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G L O B A L A N A L Y T I C A L S O L U T I O N S<br />

www.gerstel.com<br />

News from <strong>GERSTEL</strong> GmbH & Co. KG · Eberhard-Gerstel-Platz 1 · D-45473 Mülheim an der Ruhr · Germany · Phone +49 (0) 2 08 - 7 65 03-0 · gerstel@gerstel.com<br />

<strong>No</strong>. 8 February 2008<br />

ISSN 1619-0076<br />

<strong>GERSTEL</strong> moves to new Headquarters<br />

Reaching for<br />

the Stars<br />

Quality control and food safety<br />

Malachite Green<br />

Automated SPE<br />

Simplify and speed<br />

up PAH analysis<br />

Residual solvents in<br />

pharmaceutical products<br />

Organic Volatile Impurities –<br />

4 minute cycle time


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Editorial<br />

In this issue<br />

News<br />

DHS: Comparing<br />

automated extraction<br />

techniques 3<br />

MPS: Integrated<br />

weighing option 5<br />

SPE: The right<br />

solution for every<br />

application 18<br />

MAESTRO: Easy sample prep 18<br />

TDS: On-line derivatization<br />

for Thermal Desorption 19<br />

ATEX: Direct Thermal Extraction<br />

in disposable micro-vials 19<br />

Application<br />

Determining Organic Volatile<br />

Impurities (OVIs) in pharmaceuticals 4<br />

PAH-humbug, or why automating<br />

your method brings joy any time 9<br />

Smoke Signals: Fireworks<br />

and Hazardous Air Pollutants 20<br />

Malachite Green: Quality control<br />

and food safety 26<br />

Report<br />

<strong>GERSTEL</strong> among<br />

Germany’s Top Innovators 9<br />

Distributor<br />

<strong>GERSTEL</strong> Distributor<br />

in South Korea 25<br />

<strong>GERSTEL</strong> online<br />

You can fi nd more information on products,<br />

applications and services on the <strong>GERSTEL</strong><br />

home page at www.gerstel.com.<br />

<strong>GERSTEL</strong> moves to new<br />

company headquarters<br />

Since September 10, 2007, <strong>GERSTEL</strong><br />

resides at 1 Eberhard-Gerstel-Platz in<br />

Mülheim an der Ruhr. The street is named<br />

after Eberhard Gerstel Sr., the company<br />

founder. The decision to stay in Mülheim<br />

an der Ruhr emphasizes our company’s<br />

longstanding ties with the city.<br />

A company with steady growth is<br />

faced with the challenge of fi nding room<br />

for the addition of new people and for the<br />

expansion of its manufacturing capacity.<br />

<strong>GERSTEL</strong> has been dealing with this<br />

welcome challenge for most of our<br />

40 year history.<br />

Since 1998,<br />

<strong>GERSTEL</strong> has<br />

had double<br />

digit annual<br />

growth.<br />

In 1999,<br />

manufacturing<br />

was relocated<br />

from company<br />

headquarters<br />

Holger Gerstel and Eberhard G.<br />

Gerstel, Managing Directors of<br />

the <strong>GERSTEL</strong> GmbH & Co. KG<br />

to nearby<br />

Duisburg,<br />

easing the<br />

crowded<br />

conditions<br />

- at least<br />

for a while. Since 2000, the number of<br />

employees has doubled, increasing the<br />

challenge to accommodate many new<br />

colleagues. Adding to this, the expansion<br />

of the products and services portfolio into<br />

the fi elds of LC and LC/MS has increased<br />

the need for laboratory space. Our LC and<br />

LC/MS solutions are well placed in target<br />

markets that are developing extremely well<br />

for the company.<br />

<strong>GERSTEL</strong> today has a world-wide<br />

presence with succesful subsidiaires in<br />

the U.S., Japan and Switzerland as well<br />

as an international network of distributors<br />

spanning more than 70 countries.<br />

With increasing market demand for<br />

<strong>GERSTEL</strong>’s sample preparation solutions<br />

for GC, GC/MS, LC and LC/MS, growth<br />

has accelerated. Staff has been added<br />

in all departments. After years of splitting<br />

up departments and remodeling existing<br />

buildings, we decided that it was time<br />

to build new, modern and effi cient<br />

headquarters. We want to offer customers<br />

maximum performance well into the<br />

future, and this can only be done if our<br />

infrastructure can support further growth.<br />

The new <strong>GERSTEL</strong> headquarters have<br />

been designed to support and improve the<br />

work fl ow and operations at all levels. The<br />

facilities were planned based on extensive<br />

employee consultation with the help of<br />

seasoned business process experts and<br />

facility planning specialists. In order to have<br />

maximum effi ciency, and best possible<br />

interaction between all departments<br />

and company personnel, three separate<br />

locations have now been reunited at <strong>No</strong>. 1<br />

Eberhard-Gerstel-platz in Mülheim an der<br />

Ruhr.<br />

Yours sincerely,<br />

Imprint<br />

Published by<br />

<strong>GERSTEL</strong> GmbH & Co. KG<br />

Eberhard-Gerstel-Platz 1<br />

45473 Mülheim an der Ruhr<br />

Germany<br />

Editorial Director<br />

Guido Deußing<br />

ScienceCommunication<br />

Neuss, Germany<br />

guido.deussing@t-online.de<br />

Translation and editing<br />

Kaj Petersen<br />

kaj_petersen@gerstel.de<br />

Scientific advisory board<br />

Eike Kleine-Benne, Ph.D.<br />

eike_kleine-benne@gerstel.de<br />

Oliver Lerch, Ph.D.<br />

oliver_lerch@gerstel.de<br />

Contact<br />

gerstel@gerstel.com<br />

Design<br />

Paura Design, Hagen,<br />

Germany<br />

www.paura.com<br />

Print<br />

BasseDruck, Hagen,<br />

Germany<br />

www.bassedruck.de<br />

ISSN 1619-0076<br />

2<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide News<br />

Comparing automated extraction techniques<br />

Dynamic Headspace (DHS)<br />

provides highest performance<br />

Traditional headspace gas chromatography<br />

(HS-GC) is a technique that is<br />

widely used to determine volatile<br />

organic compounds (VOCs) in liquid<br />

or solid samples. HS-GC is a rugged and<br />

simple-to-perform technique that is easily<br />

automated. Unfortunately, HS-GC does<br />

not provide the level of sensitivity achievable<br />

by Headspace-Solid Phase MicroExtraction<br />

(HS-SPME)-GC or by Dynamic Headspace<br />

(DHS)-GC. <strong>GERSTEL</strong> set out to compare<br />

the performance of these three techniques<br />

based on a range of analytes and the following<br />

sample matrices: ground coffee, shower<br />

gel and cheese. The <strong>GERSTEL</strong> MultiPurpose<br />

Sampler (MPS) ensured that all three techniques<br />

were reliably automated.<br />

„Whether for the extraction and concentration<br />

of analytes from shower gel, coffee<br />

or cheese, the DHS technique won out<br />

in all cases while providing quality of results<br />

in terms of repeatability equal to the other<br />

techniques. DHS is simply more sensitive,<br />

Coffee: The DHS technique won out in all cases<br />

providing lower detection limits”, says Eike<br />

Kleine-Benne, Ph.D., R&D project manager<br />

for <strong>GERSTEL</strong>.<br />

In DHS, equilibrium between the phases<br />

is deliberately avoided as analytes are<br />

purged away from the sample headspace<br />

and trapped on a suitable adsorbent. This<br />

means that analytes are more efficiently<br />

removed from the liquid, viscous or solid<br />

sample and transferred to the analysis system<br />

providing a marked improvement in<br />

sensitivity and detection limits compared<br />

with classical Headspace GC.<br />

DHS is a simple and reliable analytical<br />

tool used to concentrate and determine<br />

small amounts of analytes from liquid<br />

or solid samples. The <strong>GERSTEL</strong> MPS<br />

performs all DHS steps in a reliable and<br />

repeatable manner. Samples are placed in<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

standard disposable 20 mL headspace vials<br />

and for each sample, a separate adsorbent<br />

tube can be used. This means that carry over<br />

from sample to sample can be completely<br />

eliminated or at least greatly reduced.<br />

For the concentration step, a number<br />

of standard adsorbents can be used, such<br />

as carbon-based adsorbents, Tenax TA or<br />

even PDMS foam sorbent. A selection of<br />

pre-packed adsorbent tubes is available.<br />

Using a tube with two or more adsorbents<br />

for the analysis enables the system to cover<br />

a wider range of polarities or a wider boiling-point<br />

range.<br />

There are no valves or transfer lines in<br />

the Thermal Desorption Unit (TDU) used<br />

to desorb the DHS tubes. This means that<br />

For more information:<br />

App<strong>No</strong>te 1/2007: „Automated Dynamic Headspace<br />

Sampling using Replaceable Sorbent Traps“,<br />

http://www.gerstel.de/p-gc-an-2007-01.<strong>pdf</strong><br />

loss of analytes is dramatically reduced. An<br />

inert gas transfers analytes efficiently from<br />

the sample to the adsorbent tube and later<br />

from the tube to the directly attached cool<br />

trap and on to the GC/MS system.<br />

Compared with SPME, the DHS adsorbent<br />

trap provides a much better phase ratio<br />

enabling significantly lower detection limits.<br />

All steps in the DHS process are selected<br />

by mouse-click in the MAESTRO software<br />

(cf. Page 18) and are performed reliably<br />

by the MPS.<br />

The steps in the DHS process are intelligently<br />

overlapped using the PrepAhead<br />

function. This means that the DHS process<br />

for a sample is performed during the<br />

GC run of the preceding sample for maximum<br />

throughput and system utilization.<br />

Since only the headspace is purged, there is<br />

no risk of foaming and system contamination<br />

and the associated instrument downtime<br />

for cleaning.<br />

The DHS process from extraction to sample introduction<br />

DHS Background<br />

and System Overview<br />

The DHS station provides sample thermostating<br />

and agitation combined with purging of<br />

the sample headspace with a controlled flow<br />

of inert gas. The result is fast, efficient and reproducible<br />

extraction of analytes from liquid<br />

or solid samples. Extracted compounds are<br />

trapped and concentrated on a replaceable<br />

adsorbent-fi lled trap, which is subsequently<br />

thermally desorbed in the integrated <strong>GERSTEL</strong><br />

Thermal Desorption Unit (TDU) followed by determination<br />

of the analytes using GC/MS.<br />

While in the <strong>GERSTEL</strong> MPS autosampler,<br />

samples are stored in standard headspace<br />

vials at ambient temperature. Optionally, samples<br />

can be stored at controlled temperatures<br />

between 4 °C to 200 °C. Lower sample temperatures<br />

can help reduce decomposition of heat<br />

sensitive samples such as food and biological<br />

materials. Higher temperatures can be used<br />

to simulate sample behavior under “stressed”<br />

conditions. During extraction, samples can<br />

be agitated to enhance and speed up the extraction<br />

process. The temperature of the adsorbent<br />

tube during the DHS process can be<br />

independently controlled from 20 °C to 70 °C<br />

for optimal trapping of the analytes of interest.<br />

The adsorbent tube can be dry purged for water<br />

removal to ensure the best possible chromatography<br />

and MS stability. A new adsorbent tube<br />

can be used for every sample, eliminating the<br />

risk of cross contamination or the same tube<br />

can be used for multiple samples as in standard<br />

Purge and Trap instruments.<br />

3


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Determining Organic Volatile Impurities (OVIs) in pharmaceutical products<br />

Organic Volatile Impurities<br />

– 4 minute cycle time!<br />

The production of pharmaceuticals is tightly regulated. US and European Pharmacopeia lay<br />

down the law: Pharmaceutical products must be analyzed for Organic Volatile Impurities<br />

(OVIs), the technique mainly used is Headspace GC.<br />

The conventional GC method used for<br />

the determination of solvent residues<br />

or Organic Volatile Impurities (OVIs)<br />

according to the European pharmacopeia<br />

typically requires a 35 minute GC run.<br />

When the Pfizer R&D Dept. in Sandwich,<br />

U.K. started looking into whether the analysis<br />

could be accelerated, they turned to<br />

the Research Institute for Chromatography<br />

(RIC) of Professor Pat Sandra. The result<br />

of the cooperation has now been published<br />

(J. Sep. Sci. 2006, 29, 695 – 698) and<br />

it shows that the method can be accelerated<br />

significantly.<br />

For the OVI determination, Pfizer was<br />

using a 6890 GC from Agilent Technologies<br />

equipped with a split/splitless inlet and<br />

a flame ionization detector (FID). The column<br />

used was a DB 624 type phase, 30 meters<br />

long, 320 μm i.d. with 1 μm film thickness.<br />

This column meets the requirements<br />

of the EU and US Pharmacopeia, enabling<br />

good separation of all listed polar and nonpolar<br />

solvents. The separation takes around<br />

35 minutes, not counting the cool down time<br />

which in turn adds between 5 and 10 minutes<br />

depending on the ambient<br />

temperature in the laboratory.<br />

The aim was to shorten the GC<br />

cycle time, improving throughput<br />

and productivity, without<br />

changing the basic method. The<br />

RIC added a Modular Accelerated Column<br />

Heater (MACH) from <strong>GERSTEL</strong> to<br />

the 6890 GC. MACH enables mounting<br />

of up to 4 column modules with standard<br />

capillaries on the GC. MACH can be programmed<br />

to heat the column at rates of up<br />

to 1800 °C/min. Cool-down of the column<br />

from 240 to 40 °C is achieved in 30 to 60 seconds<br />

depending on the column length.<br />

4<br />

MACH is based on Low Thermal Mass<br />

(LTM) technology that only heats the GC<br />

column. Unlike standard GC ovens, MACH<br />

column modules do not use large amounts<br />

of insulation, metal chambers, and large volumes<br />

of air, all of which need to be heated<br />

and cooled over the course of a temperature<br />

programmed analysis cycle. Because MACH<br />

technology does not require the heating and<br />

cooling of these ancillary components, significantly<br />

shorter GC cycle times and higher<br />

sample throughput can be achieved. MACH<br />

is controlled from Agilent Technologies’<br />

ChemStation software or directly through<br />

the MAESTRO software.<br />

Upgrade your GC in less<br />

than 30 minutes<br />

The 6890 GC was upgraded by replacing<br />

the standard oven door with a MACH system<br />

that can hold up to four modules.<br />

After about 30 minutes, MACH<br />

had been installed and the GC reconfigured<br />

and ready to run. Column modules were<br />

mounted on the outside of the GC using<br />

an opening in the MACH GC oven door.<br />

During the run, the GC oven is kept isothermal<br />

at high temperature. This means<br />

that no special accessories or connectors are<br />

required to keep the column ends and connectors<br />

heated, minimizing system complexity.<br />

<strong>No</strong>t having to cycle the GC oven<br />

temperature provides energy savings. <strong>No</strong><br />

heating energy is expended to repeatedly<br />

heat the oven to high temperatures. This<br />

in turn means that less heat is released to<br />

the lab environment and subsequently that<br />

less energy is required for air conditioning<br />

in the summer.<br />

For the task at hand, the RIC chose a<br />

MACH module with a column that was<br />

shorter and with smaller internal diameter<br />

than the one originally used by Pfizer: DB<br />

624 stationary phase, 25 meters long, 180 μm<br />

I.D. and 1 μm film thickness. This column<br />

provides more efficiency per unit length of<br />

column as well as enhanced speed of separation.<br />

The improvement was significant:<br />

Separation of a 20 solvent mixture was<br />

achieved in approximately 2.7 minutes<br />

– with good sensitivity, reproducibility,<br />

and linearity over a wide concentration<br />

range. Thanks to ultra-efficient cooling,<br />

the cycle time was reduced to a total<br />

of only 4 minutes.<br />

GC/MS-System from Agilent<br />

Technologies with the <strong>GERSTEL</strong> MultiPurpose<br />

Sampler (MPS XL) and <strong>GERSTEL</strong> Modular<br />

Accelerated Column Heater (MACH).<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Retention time (min) Area LOD Correlation<br />

Mean SD RSD (%) RSD (%) % ( w / w ) r 2<br />

Methanol 0.888 0.0005 0.055 2.85 0.0060 0.9960<br />

Pentane 1.054 0.0005 0.051 0.77 0.0001 0.9993<br />

Ethanol 1.085 0.0000 0.000 3.90 0.0041 0.9976<br />

Diethyl-Ether 1.110 0.0000 0.000 1.25 0.0002 0.9998<br />

Acetone 1.180 0.0004 0.032 2.28 0.0005 0.9948<br />

2-Propanol 1.213 0.0004 0.031 4.93 0.0036 0.9991<br />

Acetonitrile 1.246 0.0004 0.030 3.30 0.0028 0.9994<br />

Dichloromethane 1.284 0.0005 0.038 3.50 0.0022 0.9984<br />

t-Butanol 1.303 0.0000 0.000 5.18 0.0028 0.9980<br />

Hexane 1.402 0.0005 0.038 1.47 0.0002 0.9999<br />

n-Propanol 1.444 0.0004 0.026 4.68 0.0082 0.9990<br />

Ethylacetate 1.549 0.0000 0.000 2.93 0.0016 0.9995<br />

Chloroform 1.603 0.0004 0.024 3.81 0.0110 0.9997<br />

Cyclohexane 1.661 0.0005 0.029 1.71 0.0003 0.9993<br />

Benzene 1.713 0.0000 0.000 2.73 0.0007 0.9998<br />

n-Butanol 1.785 0.0007 0.039 5.41 0.0237 0.9972<br />

1,4-Dioxane 1.874 0.0005 0.026 7.70 0.0033 0.9904<br />

4-Methyl-2-Pentanone 1.985 0.0004 0.019 8.21 0.0031 0.9985<br />

Toluene 2.028 0.0000 0.000 3.10 0.0014 0.9995<br />

n-Butylacetate 2.130 0.0004 0.018 7.03 0.0044 0.9974<br />

List of solvents with retention times (min),<br />

standard deviations and relative standard<br />

deviations (%) of the retention times. Additionally,<br />

relative standard deviations are listed for the peak<br />

areas obtained using a System Suitability Test mix<br />

(6 μg/mL test mix in DMAC, n=6, RSD% for the<br />

raw peak areas). Limits of Detection (% w/w) are<br />

listed based on S/N=3 in addition to the linearity<br />

achieved (r²) for a three point calibration curve<br />

spanning concentrations 6, 25 and 100 μg/mL.<br />

Separation of a 20 component<br />

solvent mixture in 2.7 minutes<br />

– including high-boiling solvent<br />

DMAC. Using MACH’s unique<br />

cooling ability, the cycle time could<br />

be reduced to 4 minutes.<br />

<strong>GERSTEL</strong> MultiPurpose<br />

Sampler (MPS) with<br />

integrated weighing option<br />

Enlarged view: Separation of a<br />

20 component solvent mixture<br />

Standard autosampler vials are placed in the<br />

balance by the MPS. Liquid samples, standards,<br />

reagents or diluents that are added<br />

are weighed and the weights registered separately.<br />

For each sample, multiple liquid additions<br />

can be defined by mouse-click in the<br />

MAESTRO software. Results are automatically<br />

transferred to pre-defined Microsoft Excel<br />

tables for convenient processing. Each sample<br />

is reported in a separate line, each addition<br />

in a separate column.<br />

When the sample preparation steps have<br />

been finalized, the MPS can introduce the prepared<br />

sample to the GC or LC system.<br />

Every step from sample preparation to sample<br />

introduction is conveniently and efficiently<br />

set up in the MAESTRO software. When combined<br />

with the Agilent ChemStation software,<br />

one integrated method and one integrated sequence<br />

table controls everything from sample<br />

prep to sample introduction and GC/MS<br />

or LC/MS analysis. The MPS weighing option<br />

simplifies the laboratory work flow as well as<br />

the data handling process, reducing the risk<br />

of operator error for improved convenience,<br />

productivity and certainty.<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

5


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Accelerating apple flavor enjoyment<br />

Fast Apple Flavor screening using<br />

SPME coupled with fast GC/MS<br />

based on standard columns<br />

Food producers invest large sums in complex fl avor analysis to ensure consistent<br />

product quality and product fl avor. Professor Pat Sandra’s Research Institute for<br />

Chromatography (RIC) has developed a HS-SPME-GC/MS method that speeds up<br />

screening of fl avor compounds.<br />

6<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Few fruits are seen as symbol of so many<br />

different things and few carry as many<br />

different meanings across human cultures<br />

as apples. Among other things, apples<br />

symbolize fertility, love, and ties to home,<br />

family and country. Lest we forget, apples<br />

equally symbolize temptation and<br />

original sin. In the U.S., the saying<br />

“as American as apple pie” refers<br />

to apples as almost a symbol<br />

of the good American life. Symbolism<br />

aside, one can still say apples<br />

are healthy and tasty, provided<br />

that they have been allowed<br />

to fully ripen in the proper way.<br />

Most frequent consumers of apples<br />

have sufficient experience to<br />

recognize a good, ripe and well<br />

developed apple when confronted<br />

with one. The speed at which<br />

an experienced person can make<br />

a correct visual and olfactory assessment of<br />

an apple cannot be beaten by analytical instrumentation<br />

to date.<br />

When, however, a brand name product<br />

relies on consistently delivering the same<br />

accepted great taste batch after batch - year<br />

in year out - more than subjective selection<br />

by humans will be required: Enter chemical<br />

analysis in the form of gas chromatography<br />

coupled with mass selective detection (GC/<br />

MSD). Professor Pat Sandra and his team at<br />

the RIC accepted the challenge to speed up<br />

the analysis of flavor compounds in apples<br />

used for a brand name product. Using a fast<br />

GC column module, the Modular Accelerated<br />

Column Heater (MACH) from GER-<br />

STEL, the RIC team was able to speed up<br />

apple flavor analysis by a factor of 10 compared<br />

with the customer analysis method,<br />

reducing the cycle time to 4.5 minutes.<br />

Andreas Hoffmann,<br />

Manager Analytical<br />

Services (Application),<br />

<strong>GERSTEL</strong><br />

Easy GC modification<br />

improves performance<br />

The speed of capillary GC analysis can be<br />

improved significantly by increasing the<br />

speed of temperature programming. Additional<br />

factors are at play, of course. Shorter<br />

columns with smaller i.d. provide a big<br />

boost. Smaller columns in return require<br />

improved pneumatic control<br />

at higher carrier gas pressures. Further,<br />

a GC inlet is needed that offers<br />

adequate dimensions (small<br />

internal volume) and a split vent.<br />

These properties enable the inlet to<br />

deliver analytes to the GC column<br />

in a narrow band, the best possible<br />

start for high-quality fast separations.<br />

Accelerating the GC separation<br />

process of course has consequences<br />

“downstream”: Faster data acquisition<br />

is needed for sufficient peak definition<br />

and accuracy of results, for this, an<br />

MSD is needed that offers faster scan rates.<br />

The RIC used a 6890 GC combined with<br />

a state-of-the-art 5975 Quadropole MSD<br />

from Agilent Technologies for this work.<br />

The 5975 enables data acquisition<br />

rates of up to 21 Hz, 21 full<br />

scans per second, while maintaining<br />

mass spectral data quality.<br />

To enable fast heating rates, the<br />

GC was equipped with a Modular<br />

Accelerated Column Heater<br />

(MACH) from <strong>GERSTEL</strong>. MACH<br />

is based on column heating modules<br />

that enable direct resistive<br />

heating at rates of up to 1800 °C /<br />

min. <strong>No</strong>t only is the column heating<br />

step accelerated by MACH:<br />

The GC column cools down from<br />

240 °C to 40 °C in as little as 30<br />

seconds, depending on the column length.<br />

Since there is little material that needs heating<br />

or cooling, the GC equilibration time<br />

can also be cut to near zero. The overall<br />

result: Ultra-short GC cycle times and a<br />

significant increase in productivity and<br />

throughput.<br />

MACH based on Low Thermal<br />

Mass (LTM) technology<br />

Unlike a traditional GC oven, the MACH<br />

module has no insulation material and no<br />

metal based oven chamber that needs to<br />

be heated or cooled along with the column<br />

over the GC cycle. MACH is controlled<br />

from the Agilent Technologies Chem-<br />

Station Software or directly through the<br />

MAESTRO software. Andreas Hoffmann,<br />

<strong>GERSTEL</strong> Applications Manager: “We don’t<br />

drill a hole in the GC oven door to mount<br />

the MACH modules; the door is replaced<br />

with a dedicated oven door that holds up<br />

to 4 MACH modules.” It takes only around<br />

30 minutes to upgrade a 6890 or 7890 GC<br />

to MACH, getting it ready to perform faster.<br />

“The column module is simply mounted<br />

from the<br />

outside through an opening in the door,<br />

not inside the GC oven. “This has the added<br />

benefit that when operating the GC oven<br />

isothermally at the maximum temperature<br />

required for the analysis, no special accessories<br />

are required to heat the end of the column<br />

or the transfer capillaries to the standard<br />

GC injector or standard GC detector.”<br />

First peel your apple, and<br />

then apply automated<br />

sample preparation and<br />

high performance column<br />

technology<br />

This is how the RIC scientists approached<br />

the task: An apple was peeled<br />

and homogenized using an Ultraturrax<br />

blender. A ten gram sample of the resulting<br />

apple sauce, or compote, was weighed<br />

into a 20 mL vial, which was capped and<br />

placed in the <strong>GERSTEL</strong> MultiPurpose Sampler<br />

(MPS) tray. Sample preparation and<br />

sample introduction to the GC/MSD system<br />

was performed by the MPS using the<br />

Headspace Solid Phase Micro Extraction<br />

(HS-SPME) technique.<br />

The SPME fibre, coated with 100 μm<br />

polydimethylsiloxane (PDMS), was placed<br />

in the sample headspace for five minutes<br />

to extract the volatile analytes. The sample<br />

temperature was held at 25 °C. The fibre was<br />

subsequently desorbed at 250 °C for 30 seconds.<br />

For maximum productivity, the MPS<br />

was set to PrepAhead mode providing overlapping<br />

sample preparation and chromatography.<br />

In PrepAhead mode, samples are<br />

prepared during the GC-run of the preceding<br />

sample. When the GC becomes ready,<br />

the next sample has been prepared and is<br />

ready to be injected. This approach helps to<br />

ensure that the GC /MSD system is never<br />

idle providing maximum productivity and<br />

system utilization.<br />

The inlet, a Cooled Injection System<br />

(CIS) from <strong>GERSTEL</strong> was fitted with a 1.5<br />

mm i.d. deactivated liner and set to split<br />

mode with a split ratio of 3:1. The Helium<br />

carrier gas was initially set to a constant<br />

pressure of 390 kPa and the column flow<br />

was set to 0.8 mL/min, which translated<br />

to a flow of 3 mL/min through<br />

the liner, sufficient for fast analyte<br />

transfer onto the GC column. The<br />

resulting sensitivity met all QC requirements.<br />

The inlet was connected to the<br />

column in the MACH module via a<br />

20 cm long, 100 μm i.d. deactivated<br />

fused silica capillary. The transfer<br />

capillary was kept inside the GC<br />

oven at 250 °C isothermal. The<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

7


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Total Ion Chromatogram (A) and detail between 1.0 and 3.0 minutes (B) of the<br />

HS-SPME-GC/MS analysis of ten grams of apple sauce / compote. For a list of<br />

compounds, see table.<br />

Mass spectrum at tR = 2.002 min (A) and NIST spectrum of 2-Methyl-1-butylacetate<br />

(B).<br />

The RIC used a 6890 GC coupled with a 5975 MSD,<br />

both from Agilent Technologies, for fast GC analysis<br />

of apple fl avor compounds. The GC was equipped<br />

with a <strong>GERSTEL</strong> MACH module providing fast<br />

separations and fast cool-down. Sample preparation<br />

was performed automatically using the <strong>GERSTEL</strong><br />

MultiPurpose Sampler. The MPS was also used<br />

to introduce the analytes to the GC inlet <strong>GERSTEL</strong><br />

Cooled Injection System (CIS). The picture shows the<br />

newer model 7890 GC with a dual MACH module.<br />

Peak number Compound RT [min] SD [min] Peak [w 1/2 min]<br />

1 Hexane 1.159 0.000 0.010<br />

2 Butanol 1.481 0.001 0.013<br />

3 Propylacetate 1.646 0.001 0.014<br />

4 Hexanal 1.814 0.001 0.007<br />

5 Butylacetate 1.869 0.000 0.007<br />

6 2-Hexenal 1.926 0.000 0.005<br />

7 1-Hexanol 1.989 0.000 0.005<br />

8 2-Methyl-1-butylacetate 2.002 0.000 0.005<br />

9 Butylpropanoate 2.045 0.000 0.005<br />

10 Pentylbutanoate 2.057 0.000 0.005<br />

11 Butylbutanoate 2.192 0.000 0.005<br />

12 Hexylacetate 2.218 0.000 0.006<br />

13 2-Methyl-butylbutanoate 2.266 0.000 0.005<br />

14 Hexylpropanoate 2.341 0.000 0.006<br />

15 Hexylbutanoate 2.445 0.001 0.006<br />

16 Estragole 2.464 0.001 0.006<br />

17 Hexyl-2-methylbutanoate 2.500 0.000 0.006<br />

18 Hexylhexanoate 2.652 0.000 0.006<br />

19 Butylbenzoate 2.663 0.000 0.006<br />

20 alpha-Farnesene 2.804 0.000 0.008<br />

Selected identifi ed fl avor compounds from a ten gram apple sauce sample, determined by HS-SPME-GC/MS. The<br />

analysis was repeated in triplicate, the standard deviation (SD) of the retention times was always below 0.001 min.<br />

column inside the MACH module was a<br />

10 metre, 100 μm i.d., DB 1 MS column<br />

with a film thickness of 1 μm. The column<br />

outlet was connected to the MSD via a 50<br />

cm long, 100 μm i.d. deactivated fused silica<br />

capillary that was also kept inside the<br />

GC oven at 250 °C. Both Transfer capillaries<br />

were connected to the column using zero-dead-volume<br />

connectors.<br />

Flavor profiling in three<br />

minutes with a GC cycle<br />

time of only 4.5 minutes<br />

The MACH module was operated with the<br />

following temperature program:<br />

Initial temperature: 25 °C, rate 50 °C/<br />

min to 105 °C, held for 0 minutes. Rate 2:<br />

250 °C/min to the final temperature of<br />

250 °C, held for 30 seconds.<br />

The transfer capillaries were kept at a<br />

constant temperature of 250 °C. The MSD<br />

Ion Source and Quadrupole temperatures<br />

were set to 230 and 150 °C respectively. The<br />

MSD was operated in fast scan mode between<br />

m/z 33 and 300. The data acquisition<br />

rate was set to 21 Hz. Unlike the classical<br />

GC oven, the MACH module cools within<br />

seconds, ensuring that the cycle time can<br />

be kept to only a few short minutes. “The<br />

complete apple flavor profile was available<br />

after three minutes and the GC/MS system<br />

was generally ready for the<br />

next analysis after 4.5<br />

minutes”, the RIC scientists<br />

reported.<br />

The peak width at<br />

half heigth (w 1/2<br />

) was<br />

within the range from<br />

0.010 to 0.014 minutes, equal to around 600<br />

to 780 milliseconds for most of the volatile<br />

organic compounds (VOCs) such as<br />

hexane, butanol and propylacetate. Peak<br />

widths (w 1/2<br />

) for all other compounds were<br />

between 0.005 and 0.007 minutes, equal to<br />

from 300 to 420 milliseconds. The narrowst<br />

peaks had a peak width of around 0.01 minutes<br />

at base line. At the set scan rate, more<br />

than ten points were taken across the peak,<br />

enabling reliable quantitation.<br />

For more information:<br />

App<strong>No</strong>te 8/2006, „Fast Screening of Apple Flavor<br />

Compounds by SPME in Combination with Fast<br />

Capillary GC–MS using a Modular Accelerated<br />

Column Heater (MACH) and Quadrupole Mass<br />

Spectrometric Detector (qMSD)“ ,<br />

http://www.gerstel.com/p-gc-an-2006-08.<strong>pdf</strong><br />

8<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Report<br />

<strong>GERSTEL</strong> among Germany’s Top Innovators<br />

The economic initiative jury “TOP 100“ has selected <strong>GERSTEL</strong> GmbH & Co. KG among the 100 most<br />

innovative medium-size German companies. It is the second time that this coveted trophy goes to <strong>GERSTEL</strong>.<br />

As in previous years, participants were<br />

questioned in great detail, in order<br />

to develop an in-depth<br />

profile. The jury’s attention was<br />

focused on five categories “ successful<br />

innovation”, “innovative<br />

climate”, “innovative processes<br />

and organization”, “support of<br />

innovation from top management”<br />

and “ innovative marketing”.<br />

The appraisal of the participating<br />

283 candidates was performed<br />

by Professor Dr. Nikolaus<br />

Franke, of the Vienna University<br />

of Economics and Business<br />

Administration.<br />

<strong>GERSTEL</strong> was selected<br />

among the TOP 100<br />

due to superior performance<br />

in most categories.<br />

“If contamination<br />

of drinking water,<br />

air or food is a concern –<br />

chemists most often will rely<br />

on instrumentation from<br />

<strong>GERSTEL</strong> GmbH & Co. KG<br />

to resolve the issue. The company,<br />

based in Mülheim an der Ruhr, sets<br />

the benchmark for chemical analytical labs<br />

in science, industry and public authorities”<br />

the organizers of this innovation competition<br />

stated.<br />

Success based on<br />

customer benefit<br />

<strong>GERSTEL</strong>’s recipe for success is a close partnership<br />

with customers: “From design to<br />

prototyping to serial production”, says Ralf<br />

Coveted award for the 5 category<br />

winners and for the Innovator of the<br />

Year: the TOP 100 trophy<br />

Bremer, “for every new product<br />

we are completely focused on<br />

the customer benefit”. The Managing<br />

Director, responsible for<br />

R&D and Production at GER-<br />

STEL adds: ”Customers come to<br />

us with their ideas because they<br />

know we can turn them into marketable,<br />

real-world products and<br />

solutions”.<br />

Often industry takes a different<br />

approach: “Traditionally<br />

in most companies new product<br />

development is focused on<br />

the manufacturer”, Professor<br />

Franke writes. Companies perform<br />

market research to find<br />

out customer needs and,<br />

based on this, generate<br />

new products. But typically<br />

the manufacturer<br />

is the active party,<br />

while the customer, who is<br />

only asked to deliver information,<br />

is in a passive role,<br />

the economist reports.<br />

Consequently up to<br />

90% of products that are launched in the<br />

market, disappear after only a very short<br />

time and a large number of innovative projects<br />

never even make it to market. A lot of<br />

the products that succeeded were based on<br />

customers’ ideas and developments. The<br />

Professor uses the snowboard as an example:<br />

It was not invented by a company, some<br />

ski freaks were bored with skis and wanted<br />

to try something different.<br />

Ralf Bremer,<br />

Managing<br />

Director, R&D<br />

and Production,<br />

<strong>GERSTEL</strong><br />

<strong>GERSTEL</strong>’s Ralf Bre mer finds distinct<br />

parallels: “Whether it is the cooled injection<br />

system (CIS), the thermal desorption system<br />

(TDS) or the <strong>GERSTEL</strong>-Twister, whenever<br />

we turned an innovative idea into a pre-production<br />

model, we used customers to properly<br />

“beta” test its operation under real lab<br />

conditions. Such real world testing provides<br />

important information on the product’s<br />

readiness for, and relevance to the market.”<br />

Ever since its founding in 1967, <strong>GERSTEL</strong><br />

has worked closely with internationally renowned<br />

scientists and users. “Being close to<br />

both customers and technical know-how has<br />

helped build up the expertise<br />

of our company”,<br />

the Managing Director<br />

says.<br />

According to Ralf<br />

Bremer, both factors are<br />

essential ingredients for<br />

the success of the company.<br />

In terms of technical<br />

know-how, GER-<br />

STEL holds more than<br />

100 patents, mostly on<br />

products and product<br />

modifications. The<br />

outlook on company<br />

growth is rosy as well,<br />

the number of employees has more than<br />

doubled from 50 to 140 over the past ten<br />

years; around 100 are based at the Mülheim<br />

an der Ruhr headquarters. The company has<br />

subsidiaries in the USA, Japan and Switzerland;<br />

and <strong>GERSTEL</strong> is represented by distributors<br />

in more than 70 countries worldwide.<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

9


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Fluorene (C 13<br />

13 H 10 )<br />

Phen<br />

an<br />

thre<br />

rene<br />

(C 14<br />

14H 10)<br />

20 12<br />

Simplifying PAH analysis<br />

PAH-humbug, or why automating your<br />

method brings joy any time of year<br />

Polycyclic aromatic hydrocarbons (PAHs) occur naturally in fossil fuels and in many raw<br />

products that are based on petrochemicals. PAHs are often needed in order to give various<br />

products desirable properties. Some PAHs on the other hand are highly toxic for humans, some<br />

are even known human carcinogens and they are known environmental pollutants. Being able<br />

to accurately determine PAH levels is extremely important for man and the environment and it<br />

is considered a key part of environmental analysis world-wide. The following article describes<br />

how to simplify and speed up PAH analysis using automated Solid Phase Extraction (SPE)<br />

coupled with Gas Chromatography and Mass Spectrometry (MS) detection.<br />

10<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

If you were to ask people in a shopping<br />

mall what the acronym PAH stands for,<br />

most might be forgiven for thinking it was<br />

some political movement. Far from it! As<br />

any chemist knows, PAH is the acronym<br />

for polycyclic aromatic hydrocarbon. As it<br />

were, many political movements would love<br />

to get the level of exposure and press coverage<br />

that PAH has. <strong>No</strong> environmental laboratory<br />

in the world can safely disregard<br />

PAH analysis.<br />

Around 100 different compounds are<br />

considered to be PAHs. The distinguishing<br />

feature of a PAH is the presence of at least<br />

two aromatic rings. Most attention, however,<br />

is focused on those PAHs that have four<br />

to seven rings.<br />

The US Environmental Protection<br />

Agency (EPA) lists 16 PAH compounds<br />

as particularly dangerous. EPA<br />

Method 610, increasingly seen<br />

as the standard world-wide<br />

method, contains the following<br />

least wanted list: Naphthalene,<br />

Acenaphthylene, Acenaphthene,<br />

Fluorene, Phenanthrene, Anthracene,<br />

Fluoranthene, Pyrene,<br />

Benzo[a]pyrene, Benzo[a]anthracene,<br />

Chrysene, Benzo[b]<br />

fluoranthene, Benzo[k]fluoranthene,<br />

Dibenz[a,h]anthracene,<br />

Benzo[g,h,i]perylene and<br />

Indeno[1,2,3-c,d]pyrene.<br />

PAHs are of major concern,<br />

Oliver Lerch, Ph.D.,<br />

<strong>GERSTEL</strong> application<br />

scientist<br />

none more so than Benzo[a]pyrene, due to<br />

its endocrine disrupting, mutagenic and<br />

highly carcinogenic properties. Once inside<br />

the human body, PAHs accumulate in<br />

fatty tissue. Adsorbed onto soot and other<br />

fine particulate matter, PAHs can penetrate<br />

deep into the lungs. PAHs are not<br />

just harmful, but persistent and ubiquitous<br />

as well: Even in the permanent ice cap<br />

of the Antarctica, anthropogenic PAHs are<br />

found.<br />

Mineral Oil – a Blessing<br />

and a Curse<br />

PAHs are found in coal, crude oil, and also<br />

in varying amounts, in products that are<br />

derived from these raw materials. Examples<br />

are tar and asphalt as well as gasoline and<br />

diesel fuel. PAHs are added to some polymer<br />

based products as well (see box); this<br />

is more often the case for products<br />

that are dyed black, but<br />

they can be added for a variety<br />

of reasons to get the proper<br />

product properties.<br />

PAHs also are formed during incomplete<br />

combustion of diesel, gasoline,<br />

heating oil, wood or tobacco. Combustion<br />

residues can therefore contain PAHs. Construction<br />

materials such as roofing and tar<br />

can contain large amounts of PAHs, these<br />

are the types of samples that were analyzed<br />

for this article. The EPA methodology was<br />

followed and the work was performed by a<br />

reputable German contract laboratory.<br />

The lab had previously relied on HPLC<br />

with fluorescence detection. This approach<br />

often required large amounts of solvent.<br />

Clean-up steps for the sample extracts had<br />

mainly been performed manually based<br />

on solid phase extraction (SPE). Following<br />

sample clean-up, eluates were evaporated<br />

and the concentrate was taken up in<br />

an HPLC-compatible solvent. In summary,<br />

the original method was based on several<br />

labor intensive manual steps.<br />

The user had a strong wish to simplify<br />

the procedure and to save time and<br />

money in the process. Oliver Lerch, Ph.D.,<br />

<strong>GERSTEL</strong> application scientist was responsible<br />

for the project: “The request we received<br />

from the contract laboratory<br />

was to determine whether the<br />

<strong>GERSTEL</strong> SPE system coupled with<br />

Large Volume Injection (LVI) and<br />

GC/MS could deliver equal or better<br />

quality of results compared with<br />

the original procedure.”<br />

The detection limit target was<br />

set at 0.01 μg/mL for each of the 16<br />

PAH compounds contained in the<br />

standard EPA test mix. The pre-GC/<br />

MS part was divided into two automated<br />

parts: Sample preparation<br />

and sample introduction. Sample<br />

preparation: The roofing and tar extracts<br />

were diluted 20:1 or 100:1 with a 50:50<br />

mixture of dichloromethane and hexane.<br />

Clean-up of the diluted extracts was performed<br />

using automated SPE. The method<br />

was calibrated over the concentration<br />

range from 0.5 to 1000 ng/mL. A solution<br />

of d10-phenanthrene in methanol<br />

was used as internal standard, 4<br />

μL were added per 1 mL sample or<br />

calibration standard.<br />

100 μL of the cleaned extract<br />

was introduced to the <strong>GERSTEL</strong><br />

Cooled Injection System (CIS)<br />

in the GC. The injection speed<br />

was almost equal to the evaporation<br />

speed of the solvent, which<br />

means the solvent was evaporated<br />

almost completely during the<br />

injection step. The solvent vapors<br />

were vented from the system<br />

through the CIS split vent.<br />

The analytes were retained<br />

in the CIS liner by keep-<br />

High PAH<br />

concentrations in<br />

consumer products<br />

Even though PAHs are feared due to their<br />

toxicity, soot containing PAHs is routinely<br />

used as additive in lesser polymers thanks<br />

to its positive effect on product properties<br />

and product quality. In one recent case,<br />

a consumer watchdog in Germany found<br />

almost 1000 milligrams PAH per kilogram<br />

material in tubing used for bicycle pumps.<br />

The highly toxic Benzo[a]pyrene was present<br />

in the rubbery black tubing at a level<br />

of 51 milligrams per kilogram. The webpage<br />

of the organization reported that the<br />

toxic compounds could be transferred to<br />

the body of the user by simply touching<br />

the product. A previous example centered<br />

on high PAH levels in tool handles such as<br />

hammers, which<br />

are held firmly<br />

against the skin<br />

for extended periods<br />

of time during<br />

normal use. Such<br />

products provide<br />

ample opportunity<br />

for transfer<br />

of the highly toxic<br />

compounds to<br />

the body of the<br />

user.<br />

PAHs are found in coal, crude oil,<br />

and also, in varying amounts, in<br />

products that are derived from<br />

these raw materials.<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

11


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Method<br />

parameters<br />

Automated MPS SPE<br />

• Cartridges: 6 mL / 1000 mg silica gel<br />

• Syringe: 1 mL<br />

• Sample vials: 1.5 mL or 4 mL<br />

• Collection vial: 10 mL<br />

CIS 4<br />

• Temperature program:<br />

10 °C – 12 °C/s – 300 °C (15 min)<br />

• Pneumatic setting: Solvent Vent<br />

GC<br />

• Oven program:<br />

45 °C (1 min) – 10°C/min – 325°C (1 min)<br />

• Carrier Gas: Helium, 1.2 mL/min, constant flow<br />

• Column: HP5-MS 30 m x 0.25 mm x 0.25 μm<br />

Detection system<br />

• MSD: SIM/SCAN 50 – 285 amu<br />

For the determination of the 16 PAH compounds in<br />

the EPA standard test mix, the following GC system<br />

was used: <strong>GERSTEL</strong> MultiPurpose Sampler (MPS),<br />

<strong>GERSTEL</strong> Solid Phase Extraction (SPE), <strong>GERSTEL</strong><br />

Cooled Injection System (CIS 4) with LN 2 Option, GC<br />

6890 and MSD 5975, both from Agilent Technologies.<br />

Calibration standard: 100 ng/mL EPA PAH standard test mix extracted using<br />

the <strong>GERSTEL</strong> SPE and analyzed by LVI GC/MS in SIM Mode.<br />

Chromatogram of a real sample (Roofi ng extract diluted 1:100),<br />

analyzed in SIM mode.<br />

Automated Sample Prep Steps<br />

The <strong>GERSTEL</strong> SPE preparation steps can be easily selected<br />

from pull-down menus in the <strong>GERSTEL</strong> MAESTRO software. The<br />

following steps were performed for each sample:<br />

• Place an empty 10 mL eluate collection vial in the SPE station<br />

• Place a new 6 mL / 1000 mg silica gel cartridge in the SPE<br />

sliding carriage<br />

• Condition the cartridge using 10 mL of a dichloromethane/<br />

hexane mixture (1:1) followed by 10 mL hexane<br />

• Introduce the sample to the SPE cartridge at a speed of<br />

10 μL / sec and collect the eluate or waste liquid<br />

• Further elute the cartridge using 8 mL of a dichloromethane/<br />

hexane (1:1) mixture. Speed: 10 μL/s<br />

• Clear out the liquid from the cartridge by pumping through<br />

3 mL of air<br />

• Discard the used cartridge into the waste receptacle<br />

• Return the collection vial to the autosampler tray<br />

ing the initial injection temperature at 10 °C.<br />

After completing the injection, the split vent<br />

was closed and the CIS heated to 300 °C using<br />

a temperature program, transferring the<br />

analytes to the GC column.<br />

New method provides<br />

answers faster<br />

Oliver Lerch was extremely happy with the<br />

results. The customer’s application was easily<br />

transferred to the <strong>GERSTEL</strong> SPE and<br />

automated. The LVI-GC/MS method gave<br />

good results. „The relative standard deviation<br />

(RSD) of the complete method certainly<br />

pleased the customer”, said Oliver Lerch, “for<br />

most of the analytes, RSDs were between 0.8<br />

and 2.8 percent using a 20 ng/L standard.”<br />

For the roofing extract samples (1:100),<br />

RSDs were between 0.4 and 9.7 percent. The<br />

required limits of determination of 0.01 μg/<br />

mL (equal to 10 ng/mL) were easily reached.<br />

In the range between 0.5 and 1000 ng/mL<br />

calibration curves were linear with correlation<br />

coefficients around 0.999. Two calibration<br />

curves were created, one for each of the<br />

sample volumes (500 μL and 1000 μL) initially<br />

extracted by the SPE cartridges.<br />

Concentrations were calculated with<br />

and without taking the d10-Phenanthrene<br />

internal standard into account. A blank extraction<br />

right after the highest standard produced<br />

a slight carry-over. Naphthalene was<br />

the only compound that showed higher<br />

RSDs and blanks. The reasons are probably<br />

twofold: Hexane and dichloromethane are<br />

not ideal solvents for naphthalene – and the<br />

12<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Chemistry of PAHs<br />

The simplest PAHs, as defined by the International Union on Pure<br />

and Applied Chemistry (IUPAC) [IUPAC nomenclature for fused-ring<br />

systems], are phenanthrene and anthracene. Smaller molecules, such<br />

as benzene and naphthalene, are not formally PAHs, although they<br />

are chemically related they are called one-ring (mono) and two-ring<br />

(di) aromatics.<br />

PAHs may contain four-, fi ve-, six- or sevenmember<br />

rings, but those with five or six are most<br />

common. PAHs composed only of six-membered<br />

rings are called alternant PAHs. Certain alternant<br />

PAHs are called „benzenoid“ PAHs. The name<br />

comes from benzene, an aromatic hydrocarbon<br />

with a single, six-membered ring. These can be<br />

benzene rings interconnected with each other by<br />

single carbon-carbon bonds and with no rings remaining<br />

that do not contain a complete benzene<br />

ring.<br />

The set of alternant PAHs is closely related to<br />

a set of mathematical entities called polyhexes,<br />

which are planar figures composed by conjoining<br />

regular hexagons of identical size.<br />

PAHs containing up to six fused aromatic rings are often known as<br />

“small” PAHs and those containing more than six aromatic rings are<br />

called „large“ PAHs. Due to the availability of samples of the various<br />

small PAHs, the bulk of research on PAHs has been of those of up to<br />

six rings. The biological activity and occurrence of the large PAHs does<br />

appear to be a continuation of the small PAHs. They are found as combustion<br />

products, but at lower levels than the small PAHs due to the kinetic<br />

limitation of their production through addition of successive rings.<br />

Additionally, with many more isomers possible for larger PAHs, the occurrence<br />

of specific structures is much smaller.<br />

PAHs possess very characteristic UV absorbance spectra. These<br />

often possess many absorbance bands and are unique for each ring<br />

structure. Thus, for a set of isomers, each isomer has a different UV<br />

absorbance spectrum than the others. This is particularly useful in the<br />

identification of PAHs. Most PAHs are also fluorescent, emitting characteristic<br />

wavelengths of light when they are excited (when the molecules<br />

absorb light). The extended pi-electron electronic structures of<br />

PAHs lead to these spectra, as well as to certain large PAHs also exhibiting<br />

semi-conducting and other behaviors.<br />

PAHs of three rings or more have low solubilities in water and a<br />

low vapor pressure. As molecular weight increases, aqueous solubility<br />

and vapor pressure decrease. The aqueous solubility decreases<br />

approximately one order of magnitude for each additional ring. PAHs<br />

Benzo[ghi]perylene (C 22 H 12 )<br />

with two rings are more soluble in water and more volatile. Because of<br />

these properties, PAHs in the environment are found primarily in soil<br />

and sediment, as opposed to in water or air. PAHs, however, are also<br />

often found in particles suspended in water and air. Natural crude oil<br />

and coal deposits contain significant amounts of PAHs, as do combustion<br />

products and smoke from naturally occurring<br />

forest fires.<br />

PAH toxicity is very structurally dependent, with<br />

isomers (PAHs with the same formula and number of<br />

rings) varying from being non-toxic to being extremely<br />

toxic. Thus, highly carcinogenic PAHs may be small<br />

or large. One PAH compound, benzo[a]pyrene, is notable<br />

for being the first chemical carcinogen to be discovered<br />

(and is one of many carcinogens found in<br />

cigarette smoke). The EPA has classified seven PAH<br />

compounds as probable human carcinogens: benz[a]<br />

anthracene, benzo[a]pyrene, benzo[b]fl uoranthene,<br />

benzo[k]fl uoranthene, chrysene, dibenz[a,h]anthracene,<br />

and indeno[1,2,3-cd]pyrene.<br />

Naphthalene (C 10 H 8<br />

constituent of mothballs),<br />

consisting sting of two coplanar bered rings sharing an edge, is anothearomatic<br />

hydrocarbon. By<br />

formal convention, it is not a true<br />

PAH, though is referred to as<br />

a bicyclic aromatic hydrocar-<br />

bon.<br />

six-mem-m-<br />

PAHs are lipophilic. Their<br />

presence ncehasbeen reported<br />

in edible bleoilsfrom different<br />

parts of the world.<br />

Source: Wikipedia<br />

compound is the most volatile of the ones<br />

determined. If the solvent mixture were optimized<br />

further, the performance for naphthalene<br />

could probably be improved.<br />

Repeat injections of a standard using the<br />

1 mL syringe yielded very respectable RSD<br />

values though slightly higher than when a<br />

100 μL syringe was used.<br />

This means it was possible to use one syringe<br />

(1 mL) for the entire process, including<br />

sample introduction, allowing everything<br />

to be automated in one batch with-<br />

out manual intervention. If the 100 μL syringe<br />

is required for sample introduction to<br />

the GC, the sample preparation step is performed<br />

for the complete batch using the 1<br />

mL syringe and the syringe then quickly exchanged<br />

to perform the sample introduction<br />

using the same sampler. If a dual rail MPS<br />

(PrepStation) is used, the syringe exchange<br />

step can be avoided since the two robot arms<br />

can be equipped with different syringes for<br />

different parts of the process. The upper robot<br />

performs the SPE step using a 1 mL or<br />

2.5 mL syringe while the lower robot performs<br />

the LVI sample introduction using a<br />

100 μL syringe. The Prep Ahead function of<br />

the MPS under MAESTRO software control<br />

enables sample preparation and analysis to<br />

be performed in parallel ensuring best possible<br />

productivity of the system.<br />

Oliver Lerch: “The determination of<br />

PAHs can be automated in a very simple<br />

and efficient manner using this system. It<br />

is all a question of having the right tool and<br />

the right method.”<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

13


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Report<br />

Guests came from around the world to congratulate and celebrate<br />

<strong>GERSTEL</strong> celebrates 40 th anniversary with<br />

grand opening of new company headquarters<br />

<strong>GERSTEL</strong> now resides in new headquarters at 1 Eberhard-Gerstel-Platz in Mülheim an<br />

der Ruhr, Germany, the town where the company was founded 40 years ago.<br />

The inauguration took place in early October, 2007, exactly 40 years after the company<br />

was founded. 140 employees as well as 150 invited guests from all over the world took<br />

part in the celebrations.<br />

Several international dignitaries from the world of analytical<br />

chemistry took the time to honor <strong>GERSTEL</strong> in speeches,<br />

among them Shanya Kane, Vice President and General<br />

Manager of the GC business for Agilent Technologies, Heiner<br />

Scherrer, Owner and General Manager of CTC Analytics AG,<br />

a leading producer of GC- and LC autosamplers world-wide, the<br />

internationally renowned chromatography expert Professor Pat<br />

Sandra from the Research Institute for Chromatography (RIC) as<br />

well as Peter Dawes, owner and president of SGE Analytical. The<br />

Analytical Chemistry Section of the Society of German Chemists<br />

was represented by Professor Werner Engewald from the University<br />

of Leipzig.<br />

The audience that had gathered<br />

in front of the stage in<br />

the entrance hall of the new<br />

<strong>GERSTEL</strong> headquarters<br />

had travelled far to<br />

take part in the festivities,<br />

some coming<br />

literally from<br />

the other side of<br />

the planet. The occasion<br />

was the in-<br />

Pat Sandra,<br />

Research Institute for<br />

Chromatography (RIC)<br />

auguration of the new headquarters coinciding with the 40th anniversary<br />

of <strong>GERSTEL</strong>. Eberhard G. Gerstel, Holger Gerstel and<br />

Ralf Bremer, managing directors of <strong>GERSTEL</strong>, took the audience<br />

through a program highlighting the milestones of the company<br />

from its humble beginnings in a remodelled garage to the impressive<br />

new buildings encompassing almost 50,000 square feet.<br />

Among the speakers, Professor Pat Sandra, internationally renowned<br />

chromatography expert from the Research Institute for<br />

Chromatography in Kortrijk, Belgium stressed the impressive de-


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Report<br />

Mr. Peter Dawes (chairman of SGE Analytical Science, left), Andreas Hoffmann<br />

(<strong>GERSTEL</strong>) and Kevin Mac Namara (Irish Distillers, right).<br />

Heiner Scherrer, owner and General Manager<br />

of CTC Analytics AG.<br />

velopment that <strong>GERSTEL</strong> has undergone since its founding. “What<br />

began in a garage in 1967 has developed into an internationally<br />

successful company with an excellent reputation”, Prof Sandra<br />

said. He described the founder, Eberhard Gerstel Sr., as a visionary<br />

with missionary zeal and an excellent sense of the needs of scientists<br />

in the laboratory who delivered first class systems. “The products<br />

and services from <strong>GERSTEL</strong> have contributed to making<br />

the world a little better”, Prof. Sandra said.<br />

“The instruments and systems that <strong>GERSTEL</strong> has developed<br />

and brought to market are used successfully by analysts<br />

worldwide to analyze chemical, pharmaceutical,<br />

food and environmental samples among<br />

others”. The list is expanding and will in future<br />

include the fields of biomedicine<br />

and biotechnology, among them the<br />

new so-called “-omics”.


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Report<br />

Shanya Kane,<br />

Vice President and<br />

General Manager<br />

for the GC business of<br />

Agilent Technologies.<br />

Shanya Kane hands Eberhard and Holger Gerstel a plaque with an engraved text,<br />

signed by Mike McMullen and Nick Roelofs, Senior Vice Presidents of Agilent<br />

Technologies: „Thank you for the many years of continuous partnership and your<br />

outstanding contribution to the success of our company.“<br />

Prof. Werner Engewald,<br />

member of the board of<br />

directors of the Society<br />

of German Chemists’<br />

(GDCh) Section Analytical<br />

Chemistry.<br />

According to Prof. Sandra, <strong>GERSTEL</strong> is especially well placed<br />

to provide solutions in the extremely promising field of metabolomics,<br />

in which smaller molecules are determined.<br />

In her speech at the inauguration, Shanya Kane, drew parallels<br />

to Hewlett-Packard (HP), the original parent company of Agilent<br />

Technologies, which was also started in a garage. Ms. Kane<br />

also talked about the Agilent-<strong>GERSTEL</strong> cooperation that started<br />

in the mid-1980’s.<br />

“Agilent is a company with extremely high standards for integrity<br />

and customer satisfaction as well as for quality and reliability”,<br />

Ms. Kane stated. “We carefully select our partners, ensuring that<br />

they meet our high standards. The fact that <strong>GERSTEL</strong> has been a<br />

respected partner of ours for over 20 years bears testament to the<br />

integrity of the company and the high quality of <strong>GERSTEL</strong> products”.<br />

Today, <strong>GERSTEL</strong> is the leading world-wide partner of Agi-<br />

lent Technologies for customer focused solutions, officially recognized<br />

by Agilent Technologies as Premier Solution Partner Platinum<br />

Level.<br />

Heiner Scherrer, who recently became sole owner of CTC Analytics,<br />

referred to the slow beginnings of the <strong>GERSTEL</strong>-CTC partnership<br />

in his speech: „At first we discretely moved about eachother’s<br />

exhibition booths, admiring the competence of the staff<br />

and the high quality of the solutions displayed. At some point we<br />

then had the first contacts and concrete steps toward cooperation<br />

were discussed. CTC Analytics is a leading worldwide producer of<br />

autosamplers for LC and GC. Heiner Scherrer expressed admiration<br />

for <strong>GERSTEL</strong> solutions: “During our cooperation, these clever<br />

people have again and again shown their ability to develop new<br />

solutions based on our platform and getting the absolute maximum<br />

out of the possibilities at hand.” Mr. Scherrer praised the<br />

16<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Report<br />

new <strong>GERSTEL</strong> Headquarters, stating that it reflects the spirit of<br />

innovation that is present in the company. “We are proud to have<br />

been part of making this success possible”, said the General Manager<br />

of CTC Analytics.<br />

In his speech at the 40th anniversary dinner, Mr. Dawes praised<br />

the successful partnership between <strong>GERSTEL</strong> and SGE. Mr. Dawes<br />

drew parallels between the two family owned companies, and their<br />

success in getting and retaining high-quality employees, a key parameter<br />

for long-term success.<br />

Prof. Werner Engewald, member of the board of directors of the<br />

Society of German Chemists’ (GDCh) Section Analytical Chem-<br />

istry extended best wishes and warmest congratulations on behalf<br />

of the Section, wishing <strong>GERSTEL</strong> “a continuation of the impressive<br />

success story, which was again confirmed in 2007 by GER-<br />

STEL’s inclusion in the Top100 rank of Germany’s most innovative<br />

medium size companies”. Prof. Engewald further spoke of his<br />

first meetings with the company founder, which led to a wonderful<br />

friendship. Prof. Engewald expressed his pleasure in announcing<br />

the new “Eberhard-Gerstel-Prize for outstanding achievements<br />

among young scientists in the fields of Gas- and Liquid Chromatography”,<br />

details of which are to be revealed later.<br />

Eberhard G. Gerstel (left) and Holger Gerstel with their mother Thea<br />

Gerstel, the widow of company founder Eberhard Gerstel.<br />

Eberhard Gerstel (1927 – 2004)<br />

From a garage to <strong>No</strong>. 1 Eberhard-Gerstel-Platz<br />

Life starts at 40. For Eberhard Gerstel Sr., this<br />

statement held true, at least in terms of his<br />

business career. Less than two months after<br />

his 40th birthday, the master precision mechanics<br />

craftsman founded his company “Laboratory<br />

Precision Mechanics Gerstel”. The first<br />

home of the company was a remodelled garage<br />

in Mülheim an der Ruhr, Germany (1). Mr.<br />

Gerstel’s analytical solutions were well accepted<br />

and success brought welcome growth to<br />

the company. The limited space available<br />

could not accommodate such growth for long<br />

and the fi rst of several moves had to be undertaken.<br />

The second address for <strong>GERSTEL</strong><br />

was a former small supermarket in Mülheim<br />

(2). <strong>GERSTEL</strong> continued to expand and was<br />

changed to a Limited Liability Company (German:<br />

GmbH). The next expansion soon had<br />

to be planned, moving the company to a former<br />

cabinet-making workshop (3) where GER-<br />

STEL continued its path of steady growth. In<br />

1<br />

2<br />

1989, a former printing plant became available.<br />

The premises were expanded significantly before<br />

<strong>GERSTEL</strong> moved in. It was thought that<br />

the space available in the Aktienstrasse (4) in<br />

Mülheim an der Ruhr would be suffi cient for<br />

at least a generation, and plans to sublet parts<br />

of the building were initially considered, but<br />

were soon dropped. Already in 1997, production<br />

had to be moved to new facilities in nearby<br />

Duisburg to make room for new employees.<br />

In 2004, the Software Development and Technical<br />

Documentation departments were moved<br />

to a site nearby. Finally, less than two decades<br />

after moving into the Aktienstrasse facilities,<br />

the fourth move was completed in September<br />

of 2007. The company founder passed away<br />

on August 30th, 2004 and so, unfortunately,<br />

was not around to experience the inauguration<br />

of the new headquarters and the 40th anniversary<br />

of <strong>GERSTEL</strong>. He will be ever-present<br />

though, the company now resides at 1 Eberhard-Gerstel-Platz<br />

in Mülheim an der Ruhr. The<br />

shiny new company headquarters offer plenty<br />

of space for the time being. The facilities were<br />

planned with a view to accommodating longterm<br />

growth. An additional floor and even an<br />

additional wing can be added to the building<br />

if and when the need arises.<br />

3<br />

4<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

17


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide News<br />

<strong>GERSTEL</strong> MultiPurpose Sampler MPS and MAESTRO software<br />

The right sample prep<br />

solution for every application<br />

Robert Collins,<br />

President,<br />

<strong>GERSTEL</strong> Inc.<br />

Ralf Bremer,<br />

Managing Director,<br />

<strong>GERSTEL</strong><br />

GmbH & Co. KG<br />

<strong>GERSTEL</strong> provides analysis laboratories with unique and comprehensive<br />

automated sample preparation solutions based on the MultiPurpose Sampler<br />

(MPS). Depending on the customer‘s needs, the MPS can be connected to<br />

a GC/MS or LC/MS system, combining automated sample prep with sample<br />

introduction. Alternatively, the MPS is available as a WorkStation to perform<br />

independent sample preparation for one or more GC/MS or LC/MS systems<br />

in the laboratory.<br />

<strong>GERSTEL</strong> SPE Solution for GC<br />

Easy sample prep<br />

with MAESTRO<br />

MAESTRO software simplifies the task of generating<br />

sample prep methods using the Prep-<br />

Builder function. Sample prep steps are selected<br />

from a pull-down menu and added to<br />

the method, enabling sample prep by mouseclick<br />

with minimal effort.<br />

The intelligent Scheduler in the MAESTRO<br />

software helps the analyst to optimize timing<br />

of both Sample Prep and analysis. Productivity<br />

and total run time for each batch of samples<br />

can be determined at a glance on the scheduler<br />

screen, you always know exactly when to<br />

have the next batch of samples ready thereby<br />

ensuring maximum throughput.<br />

This convenience and productivity feature<br />

is a great help when planning the laboratory<br />

work-flow. Sample Prep steps are performed<br />

during the GC or LC run of the preceding sample<br />

for best possible productivity and highest<br />

system utilization.<br />

The sample prep techniques performed by<br />

the MPS range from standard addition and<br />

derivatization through Twister (SBSE) and Dynamic<br />

Headspace (DHS) to Automated Solid<br />

Phase Extraction (SPE).<br />

Contract laboratories operate in a highly<br />

competitive environment. Prices<br />

are under pressure while customer<br />

expectations are on the rise. Labs are expected<br />

to deliver results ever faster, providing<br />

ever higher quality in terms of reproducibility<br />

and reliability – and, of course,<br />

combined with ever lower limits of detection.<br />

The outlook is that the market will<br />

demand even more even faster. Therefore<br />

it is no surprise that many labs are looking<br />

to automating their sample preparation as<br />

much as possible.<br />

As a logical consequence, a large number<br />

of laboratory automation products and robots<br />

will be on display at analytical chemistry<br />

related exhibitions, among them the upcoming<br />

PittCon 2008 (March 3 to 6, 2008)<br />

in New Orleans and the Analytica 2008 in<br />

Munich, Germany.<br />

<strong>GERSTEL</strong> offers the discerning analyst<br />

novel technologies for extraction and analyte<br />

concentration as well as high-performance<br />

integrated systems for sample preparation<br />

and introduction including GC/MS or LC/<br />

MS. The following offers some detail:<br />

<strong>GERSTEL</strong> SPE Solution for GC<br />

The <strong>GERSTEL</strong> SPE Solution for GC has a lot<br />

to offer the user. It is based on the Multi-<br />

Purpose Sampler (MPS), a modular autosampler<br />

and sample preparation robot<br />

that can be upgraded with a series of sampling<br />

and sample preparation options as<br />

the need arises. Among the available options<br />

are:<br />

• Liquid introduction of up<br />

to 34<strong>56</strong> samples<br />

• Standard addition, derivatization,<br />

dilution and extraction<br />

• Stirring, agitation, heating and<br />

cooling of samples<br />

• Automated Weighing Option<br />

• Dynamic Headspace (DHS),<br />

Headspace and SPME<br />

• Stir Bar Sorptive Extraction(SBSE)<br />

using the <strong>GERSTEL</strong> Twister<br />

• Thermal extraction of liquids in<br />

micro-vials (ATEX)<br />

• Solid Phase Extraction (SPE)<br />

David Singer,<br />

National<br />

Sales Manager,<br />

<strong>GERSTEL</strong>, Inc.<br />

The MPS is available as a completely integrated<br />

system with a GC/MSD from Agilent<br />

Technologies. The sampler can be operated<br />

independently through the <strong>GERSTEL</strong><br />

MAESTRO software control or fully integrated<br />

with the ChemStation from Agilent<br />

Technologies. Just one method and one<br />

sequence table is required to operate the<br />

complete system from sample preparation<br />

through sample introduction to GC/MS<br />

analysis providing efficient operation with<br />

less risk of error.<br />

<strong>GERSTEL</strong> SPE Solution for LC<br />

The <strong>GERSTEL</strong> SPE Solution for LC enables<br />

automated sample preparation and sample<br />

introduction using a number of techniques:<br />

• Liquid introduction of up<br />

to 34<strong>56</strong> samples<br />

• Standard addition, derivatization,<br />

dilution and extraction<br />

• Stirring, agitation, heating and<br />

cooling of samples<br />

• Automated Weighing Option<br />

• SBSE and Twister Back Extraction (TBE)<br />

• Membrane Assisted Solvent<br />

Extraction (MASE)<br />

• Solid Phase Extraction (SPE)<br />

The MPS is available as a completely<br />

integrated solution with an LC/MS system<br />

from Agilent Technologies. The sampler<br />

can be operated independently through the<br />

<strong>GERSTEL</strong> MAESTRO software control or<br />

18<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide News<br />

Thermal Desorption System (TDS)<br />

On-line derivatization for Thermal Desorption<br />

To learn more about <strong>GERSTEL</strong><br />

solutions, please visit <strong>GERSTEL</strong> at<br />

the 59th Pittsburgh Conference,<br />

March 1 – March 7, 2008, Ernest N.<br />

Morial Convention Center, New Orleans,<br />

Louisiana. The <strong>GERSTEL</strong>-Team is looking<br />

forward to welcoming you on Booth # 4827.<br />

P.S. Further information about <strong>GERSTEL</strong><br />

and our products is available on the web<br />

under www.gerstel.com and<br />

www.gerstelus.com (USA).<br />

fully integrated with the ChemStation from<br />

Agilent Technologies. Just one method and<br />

one sequence table is required to operate<br />

the complete system from sample preparation<br />

through sample introduction to LC/MS<br />

analysis providing efficient operation with<br />

less risk of error.<br />

Depending on the customer preferences,<br />

<strong>GERSTEL</strong> can provide the complete<br />

system or just the sample preparation and<br />

sample introduction solution. Everything<br />

is available from a single source including<br />

application support, maintenance and service<br />

support such as IO/OQ-PV.<br />

<strong>GERSTEL</strong> SPE<br />

WorkStation Solution<br />

A WorkStation SPE Solution is available<br />

for laboratories that want high-performance,<br />

flexible sample preparation independent<br />

of their GC/MS or LC/MS systems.<br />

The <strong>GERSTEL</strong> SPE WorkStation Solution<br />

is based on the <strong>GERSTEL</strong> Multi-<br />

Purpose Sampler (MPS), a modular sample<br />

preparation robot. The system can be<br />

upgraded with one or more of a series of<br />

sampling and sample preparation options<br />

as the need arises. In short, the SPE Work-<br />

Station adapts to, and grows with, your laboratory<br />

productivity needs.<br />

And, of course, the MAESTRO software<br />

runs everything at the click of a mouse. Samples<br />

can be weighed automatically, agitated,<br />

stirred, cooled or heated. A standard or a<br />

derivatization reagent can be added automatically;<br />

samples can be processed in any<br />

order to best serve the needs of the laboratory;<br />

sample prep steps can<br />

be performed in parallel for<br />

maximum productivity and<br />

throughput. Sample Prep<br />

was never this easy.<br />

<strong>GERSTEL</strong> Solid Phase<br />

Extraction Solution for<br />

Liquid Chromatography<br />

In order to determine semi-volatile or thermally<br />

labile compounds by gas chromatography<br />

(GC), these must often be derivatized prior<br />

to analysis. While derivatization is routinely<br />

performed by many laboratories, it is not a trivial<br />

matter. Depending on the analysis and the<br />

derivatization agent used, it can be cumbersome<br />

and difficult to perform. Mostly, derivatization<br />

is performed in solution. In the case<br />

of thermal desorption analysis, it is preferable<br />

to add a gaseous derivatization reagent. GER-<br />

STEL has developed a module for the Thermal<br />

Desorption System (TDS 3), that enables online<br />

derivatization of analytes during the thermal<br />

desorption phase.<br />

The on-line derivatization<br />

module delivers a reagent<br />

into the carrier gas flow and<br />

thereby to the thermal desorption<br />

tubes. Analytes are<br />

derivatized and volatilized<br />

for subsequent GC or GC/<br />

MS determination. The derivatization<br />

agent is added<br />

during thermal desorption<br />

Automated Liquid Sample Introduction<br />

Direct Thermal Extraction in<br />

disposable micro-vials<br />

Automated TDU-Liner Exchange<br />

(ATEX) is a new sample<br />

preparation option for the<br />

<strong>GERSTEL</strong> MultiPurpose Sampler<br />

(MPS) in combination with<br />

the <strong>GERSTEL</strong> Thermal Desorption<br />

Unit (TDU).<br />

The ATEX option enables<br />

the introduction of liquid samples<br />

directly into micro-vial inserts<br />

used for thermal extraction<br />

/ thermal desorption in the<br />

TDU.<br />

Extracted analytes are refocused<br />

and concentrated in a<br />

Cooled Injection System (CIS)<br />

inlet prior to introduction to the GC/MS system.<br />

Efficient extraction and concentration ensures<br />

highest possible sensitivity and lowest detection<br />

limits.<br />

After the concentrated analytes have been<br />

introduced to the GC/MS system, the microvial<br />

sample cup with the remaining high-boiling<br />

or solid residue is automatically removed.<br />

ATEX helps to ensure maximum uptime and best<br />

possible analysis results by keeping involatile or<br />

complex matrix material out of the GC/MS system.<br />

ATEX micro-vials can be used for liquid or<br />

only and can be switched off by deselecting<br />

the function in the MAESTRO software<br />

TDS method page.<br />

The on-line derivatization module for the<br />

<strong>GERSTEL</strong> TDS; it has been used successfully<br />

in forensic applications, determining<br />

residual solvents and other chemical compounds<br />

in ink in order to determine the age<br />

of printed or handwritten text. Examples<br />

could be parts of signatures or numbers in<br />

a document that may have been added after<br />

the document was originally signed.<br />

solid samples. Up to 196 samples<br />

can be processed automatically<br />

for determination of VOCs<br />

and SVOCs in heavy or involatile<br />

matrices. Standard addition and<br />

other sample preparation steps<br />

can be performed auto matically<br />

by<br />

the MPS.<br />

The complete system is operated<br />

through the <strong>GERSTEL</strong><br />

MAESTRO software either<br />

stand-alone or integrated with<br />

the Agilent ChemStation. Just<br />

one method and one sequence<br />

table controls the complete process<br />

from sample introduction<br />

through thermal desorption to GC/MS analysis<br />

ensuring the simplest possible and most productive<br />

operation.<br />

Suggested applications are the determination<br />

of VOC or SVOC concentrations in high-boiling<br />

or involatile matrices by thermal extraction, also<br />

referred to as dynamic headspace analysis<br />

or stripping. Examples are: Residual solvents<br />

in packaging material; plasticizers in packaging<br />

material and in foods such as edible oils; and<br />

flavor and fragrance compounds in household<br />

products or personal care products.<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

19


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

A message to partygoers on New Year‘s eve<br />

Smoke signals<br />

by Kaj Petersen<br />

Fireworks weave beautiful patterns in the night skies and fl eetingly<br />

place brightly colored stars in the canopy above us. Closer to the<br />

ground we are awed by fountains of shooting stars, beautiful suns<br />

and loud fi recrackers. While these visual and acoustic impressions<br />

never cease to excite and please onlookers, our respiratory system<br />

begs to differ. The air quality plummets towards levels last seen in<br />

areas with heavy industry and coal heating in days of yore. Every<br />

rocket fi red on New Year’s Eve releases signifi cant amounts of<br />

Kaj Petersen,<br />

Marketing Manager<br />

<strong>GERSTEL</strong><br />

fi ne particulate matter according to the German Federal Environmental Agency<br />

(UBA). Incidentally, just because particulate matter is labeled “fi ne” that doesn’t<br />

mean it is good or healthy. Rather, the “fi ne” particles are small enough to<br />

penetrate to the inner reaches of our lungs, from where they can no longer be<br />

exhaled. They then proceed onward through the blood vessels or the lymphatic<br />

system to the entire body, potentially carrying a load of toxic chemicals with<br />

them. Scientists from Korea have now shown that Hazardous Air Pollutants<br />

(HAPs) are also released in signifi cant amounts by fi reworks.


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Halogenated and aromatic compounds<br />

Isoparaffi nic compounds<br />

1,1-Dichloroethylene Bromobenzene Isopentane<br />

Methylene chloride 1,3,5-Trimethylbenzene 2,3-Dimethylbutane<br />

trans-1,2-Dichloroethane 2-Chlorotoluene 2-Methylpentane<br />

1,1-Dichloroethane 4-Chlorotoluene 3-Methylpentane<br />

2,2-Dichloropropane tert-Butylbenzene 2,2-Dimethylpentane<br />

cis-1,2-Dichloroethylene 1,2,4-Trimethylbenzene 2,4-Dimethylpentane<br />

Chloroform sec-Butylbenzene 2,2,3-Trimethylbutane<br />

Bromochloromethane 4-Isopropyltoluene 3,3-Dimethylpentane<br />

1,1,1-Trichloroethane 1,3-Dichlorobenzene 2-Methylhexane<br />

1,1-Dichloropropene 1,4-Dichlorobenzene 2,3-Dimethylpentane<br />

Carbon tetrachloride n-Butylbenzene 3-Methylhexane<br />

1,2-Dichloroethane 1,2-Dichlorobenzene 3-Ethylpentane<br />

Benzene 1,2-Dibromo-3-chloropropane 2,2-Dimethylhexane<br />

Trichloroethane 1,2,4-Trichlorobenzene 2,5-Dimethylhexane<br />

1,2-Dichloropropane Hexachlorobutadiene 2,2,3-Trimethylpentane<br />

Bromodichloromethane Naphthalene 2,4-Dimethylhexane<br />

Dibromomethane 1,2,3-Trichlorobenzene 2,3-Dimethylhexane<br />

cis-1,3-Dichloropropene<br />

2-Methylheptane<br />

Toluene<br />

4-Methylheptane<br />

trans-1,3-Dichloropropene<br />

3-Methylheptane<br />

1,1,2-Trichloroethane<br />

3-Ethylhexane<br />

1,3-Dichloropropane<br />

2,5-Dimethylheptane<br />

Tetrachloroethane<br />

3,5-Dimethylheptane(D)<br />

Dibromochloromethane<br />

3,3-Dimethylheptane<br />

1,2-Dibromoethane<br />

3,5-Dimethylheptane(L)<br />

Chlorobenzene<br />

2,3-Dimethylheptane<br />

1,1,1,2-Tetrachloroethane<br />

3,4-Dimethylheptane(D)<br />

Ethylbenzene<br />

3,4-Dimethylheptane(L)<br />

m-Xylene<br />

2-Methyloctane<br />

p-Xylene<br />

3-Methyloctane<br />

o-Xylene<br />

3,3-Diethylpentane<br />

Styrene<br />

2,2-Dimethyloctane<br />

Isopropylbenzene<br />

3,3-Dimethyloctane<br />

Bromoform<br />

2,3-Dimethyloctane<br />

1,1,2,2-Tetrachloroethane<br />

2-Methylnonane<br />

1,2,3-Trichloropropane]<br />

3-Ethyloctane<br />

n-Propylbenzene<br />

3-Methylnonane<br />

Olefinic compounds<br />

3-Methyl-1-Butene<br />

1-Pentene<br />

2-Methyl-1-Butene<br />

2-Methyl-1,3-Butadiene<br />

trans-2-Pentene<br />

cis-2-Pentene<br />

4-Methyl-1-Pentene<br />

1-Hexene<br />

trans-2-Hexene<br />

2-Methyl-2-Pentene<br />

cis-2-Hexene<br />

1-Heptene<br />

trans-3-Heptene<br />

cis-3-Heptene<br />

trans-2-Heptene<br />

cis-2-Heptene<br />

1-Octene<br />

trans-2-Octene<br />

cis-2-Octene<br />

1-<strong>No</strong>nene<br />

trans-3-<strong>No</strong>nene<br />

cis-3-<strong>No</strong>nene<br />

trans-2-<strong>No</strong>nene<br />

cis-2-<strong>No</strong>nene<br />

1-Decene<br />

Naphthtenic compounds<br />

cyclopentene<br />

Methylcyclopentane<br />

Cyclohexane<br />

1,1-Dimethylcyclopentane<br />

cis-1,3-Dimethylcyclopentane<br />

trans-1,3-Dimethylcyclopentane<br />

trans-1,2-Dimethylcyclopentane<br />

Methylcyclohexane<br />

Ethylcyclopentane<br />

ctc-1,2,4-Trimethylcyclopentane<br />

ctc-1,2,3-Trimethylcyclopentane<br />

cct-1,2,4-Trimethylcyclopentane<br />

trans-1,4-Dimethylcyclohexane<br />

1-Ethyl-1-Methylcyclopentane<br />

trans-1,2-Dimethylcyclphexane<br />

ccc-1,2,3-Trimethylcyclopentane<br />

Isopropylcyclopentane<br />

cis-1,2-Dimethylcyclopentane<br />

n-propylcyclopentane<br />

ccc-1,3,5-Trimethylcyclohexane<br />

1,1,4-Trimethylcyclohexane<br />

ctt-1,2,4-Trimethylcyclohexane<br />

ctc-1,2,4-Trimethylcyclohexane<br />

1,1,2-Trimethylcyclohexane<br />

Isobutylcyclopentane<br />

Isopropylcyclohexane<br />

n-Butylcyclopentane<br />

Isobutylcyclohexane<br />

t-1-Methyl-2-Propylcyclohexane<br />

t-1-Methyl-2(4MP)Propylcyclopentane<br />

Table: List of determined Hazardous Air Pollutants (HAPs)<br />

If your first and foremost sensation on<br />

New Year’s Day is a throbbing headache,<br />

accompanied by a desire to spend the rest<br />

of the year in bed, it need not be due to excessive<br />

alcohol consumption. It could be related<br />

to the noise levels experienced on New<br />

Year’s Eve. Equally the culprits could be the<br />

increasing levels of Hazardous Air Pollutants<br />

(HAPs) accompanied by particulate matter<br />

that you have been inhaling the night before<br />

as more and more fireworks were sent<br />

off into the skies. Even as eyes are burning<br />

and we start wheezing and coughing, tradition<br />

is adhered to and we duly continue to<br />

send off the old year and welcome in the new<br />

with loud and beautiful displays of joy. Handling<br />

fireworks poses a challenge in terms of<br />

keeping fingers, hands, face and eyes out of<br />

harm’s way. Other, less visible, harm can be<br />

done when fireworks do what they do best<br />

– burn at high temperatures. The “smoke”<br />

we see is largely made up of aerosols and of<br />

particulate matter (PM) and an accompanying<br />

cocktail of toxic chemicals. The particulate<br />

matter that is of most interest, in terms<br />

of health effects, is PM 10<br />

. These are particles<br />

that are less than 10 μm in diameter (< 0.01<br />

mm O.D.) and thus not visible to the naked<br />

eye. The German Federal Environmental<br />

Agency (UBA) website provides the following<br />

information: “Fine particulate matter<br />

has a proven negative impact on health.<br />

With decreasing particle size, the risk to our<br />

health increases”.<br />

Ongoing and recent monitoring in Germany<br />

has shown that levels of toxic particulate<br />

matter on New Year’s Eve are higher<br />

than on any other day of the year: In the first<br />

hours of 2007, inner city PM 10<br />

levels of up to<br />

4,000 μg/m 3 were measured (4,000 μg/m 3 =<br />

4,000 micrograms PM 10<br />

per cubic meter air).<br />

For comparison, the mean PM 10<br />

concentration<br />

measured at inner city monitoring stations<br />

in Germany throughout 2006 was only<br />

around 30 μg per cubic meter air.<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

21


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Prof. Gon Ok from the Department<br />

of Earth Environmental Engineering<br />

at the Pukyong National University.<br />

<strong>GERSTEL</strong><br />

Gas Sampler GS 1<br />

Schematic diagram of a reactor<br />

system used for fi recrackers.<br />

Adsorbent Packing of Thermal desorption tube.<br />

Technical and analysis detail<br />

In addition to particulate matter, the fumes<br />

released during and after the combustion<br />

of fire-work materials contain significant<br />

amounts of Hazardous Air Pollutants<br />

(HAPs). This is the conclusion reached by<br />

scientists at the Pukyong National University<br />

in Busan, Korea. Since fireworks are<br />

among the favorite pastimes of Koreans, the<br />

scientists set out to determine the environmental<br />

impact of fireworks and the quality<br />

of the air breathed by those in the area<br />

where the spectacle unfolds. In short, the<br />

goal of the project was to get quantitative<br />

data about HAP concentrations. Prof. Gon<br />

Ok and his colleagues from the Department<br />

of Earth Environmental Engineering at the<br />

Pukyong National University proceeded as<br />

follows to determine the increase in HAP<br />

concentrations during fireworks: Air samples<br />

were taken at a beach in Haeundae in<br />

the summer season, when tourists light up<br />

an estimated 1,000 – 2,000 firecrackers per<br />

night, or 50,000 – 100,000 per season pursuing<br />

their pyrotechnical hobby.<br />

For comparison, air samples were<br />

drawn in the urban area around the university<br />

where firecracker fuses are rarely, if<br />

ever, lit as a leisure activity.<br />

“In order to provide quantitative results<br />

and solid conclusions“, Prof. Gon Ok explains,<br />

“we developed a special reactor in<br />

which we can explode fireworks under controlled<br />

laboratory conditions while sampling<br />

the emitted gases for analysis.<br />

The resulting gases were sampled using<br />

the <strong>GERSTEL</strong> Gas Sampler GS 1 directly attached<br />

to the fireworks reactor. Gas samples<br />

were drawn onto thermal desorption<br />

tubes filled with carbon-based absorbents,<br />

Carbosieve S-III, Carbopack B, and Carbopack<br />

C. Sampling and analysis was performed<br />

following US-EPA method TO-17:<br />

“Determination of Volatile Organic Compounds<br />

in Ambient Air Using Active Sampling<br />

Onto Sorbent Tubes”. The tubes were<br />

subsequently thermally desorbed using a<br />

<strong>GERSTEL</strong> Thermal Desorption System<br />

22<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Total<br />

ion<br />

chromatograms ms of HAPs by GC/MS<br />

(TDS) and the analytes were refocused in<br />

the Cooled Injection System (CIS) mounted<br />

in an Agilent Technologies GC 6890.<br />

TDS tubes packed with the same types of<br />

adsorbent were used to sample air at the<br />

beach of Haeundae. Compound identification<br />

and quantification were performed<br />

using an Agilent MSD 5973.<br />

Thermal desorption of analytes from the<br />

TDS tube was performed using a temperature<br />

program: The starting temperature was<br />

set to 30 °C, ramping at a rate of 60 °C/min<br />

to an end temperature of 220 °C. Helium<br />

carrier gas was used. Cryofocusing was performed<br />

at -50 °C in the CIS. The CIS was<br />

subsequently heated at a rate of 8 °C per second<br />

to 220 °C, transferring the analytes to<br />

the GC column (Supelco VOCOL, 60 m x<br />

320 μm x 1.8 μm). The GC oven temperature<br />

program started at 30 °C, with an initial<br />

hold time of 5 minutes. The oven was first<br />

ramped at 3 °C/min to 60 °C, followed by a<br />

second ramp at 5 °C/min to 150 °C and a third<br />

ramp of 2 °C/min to the end temperature of<br />

190 °C, which was held for 2 minutes.<br />

Results and Discussion<br />

In total, around 150 different HAPs were<br />

detected in the gases emitted from the fireworks<br />

reactor. Among these were 60 different<br />

aromatic compounds, 35 isoparaffines,<br />

20 olefines and 30 naphthenes (see table).<br />

Armed with this knowledge, the scientists<br />

went about analyzing air samples from<br />

the beach at Haeundae.<br />

The results were a wake-up call. Inner<br />

city air levels of HAPs near the Pukyong National<br />

University, were between 2.5 ppb and<br />

42 ppb as an annual average. BTEX compounds<br />

made up 99.9 percent of the total<br />

concentration of aromatic compounds.<br />

HAP concentrations at the beach frequented<br />

by the noise-loving pyrotechnic enthusiasts<br />

were normally around a factor of ten<br />

higher for m- and p-xylene and a factor of<br />

400 higher for benzene. The BTEX contribution<br />

was 69 percent and at 1,260 ppb<br />

the concentration was significantly higher<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

23


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Concentrations of HAPs in the squib reactor<br />

Concentrations of HAPs in Haeundae beach air during fi rework<br />

Halogenated and<br />

aromatic compounds ppb Isoparaffinic compounds ppb<br />

Dichloromethane 2877 3-Methylpentane 26.59<br />

trans-1,2-Dichloroethylene 2005 2,4-Dimethylhexane 0.065<br />

1,1-Dichloroethane 1106 Sum 26.66<br />

Chloroform 6.085<br />

Benzene 91360 Olefinic compounds ppb<br />

Trichloroethylene 26.21 3-Methyl-1-butene 14.71<br />

Toluene 6954 1-Pentene 43.29<br />

Chlorobenzene 284.0 2-Methyl-1-butene 19.08<br />

Ethylbenzene 818.4 cis-2-Pentene 19.44<br />

m,p-Xylene 484.8 2-Methyl-1,3-butadiene 11.34<br />

o-Xylene 699.2 1-Hexene 18.42<br />

Styrene 2133 trans-2-Hexene 2.762<br />

Isopropylbenzene 22.13 2-Methylpentene-2 0.326<br />

n-Propylbenzene 57.26 cis-2-Hexene 0.108<br />

1,3,5-Trimethylbenzene 28.45 1-Heptene 2.304<br />

2-chlorotoluene 1.135 trans-3-Heptene 0.205<br />

tert-Butylbenzene 0.000 trans-2-Heptene 0.128<br />

1,2,4-Trimethylbenzene 99.76 1-Octene 2.449<br />

sec-Butylbenzene 1.403 1-<strong>No</strong>nene 2.604<br />

p-Isopropyltoluene 41.34 cis-2-<strong>No</strong>nene 0.283<br />

1,3-Dichlorobenzene 10.82 1-Decene 4.804<br />

1,4-Dichlorobenzene 1.047 Sum 142.3<br />

n-Butylbenzene 24.31<br />

1,2-Dichlotobenzene 0.696 Naphthenic compounds ppb<br />

1,2,4-Trichlorobenzene 2.100 Methylcyclopentane 0.792<br />

Naphthalene 422.8 trans-1,3-Dimethylcyclopentane 2.245<br />

1,2,3-Trichlorobenzene 2.260 cct-1,2,4-Trimethylcyclopentane 3.392<br />

Sum 109500 Sum 6.429<br />

Halogenated and<br />

aromatic compounds ppb Isoparaffinic compounds ppb<br />

Dichloromethane 476 2-Methylheptane N.D.<br />

Benzene 690 3-Methylheptane N.D.<br />

Toluene 557 2-Methyloctan N.D.<br />

Ethylbenzene 6.05 3-Methyloctan N.D.<br />

m,p-xylene 4.66 Sum -<br />

O-xylene 3.58 Olefinic compounds ppb<br />

Styrene 9.84 1-Pentene 41.1<br />

Isopropylbenzene 0.33 1-Heptene 12.2<br />

n-Propylbenzene 0.93 1-Decene 8.<strong>56</strong><br />

1,3,5-Trimethylbenzene 1.04 Sum 61.9<br />

1,2,4-Trimethylbenzene 3.27 Naphthenic compounds ppb<br />

1,4-Dichlorobenzene 1.51 Methylcyclopentane 9.90<br />

Naphthalene 1.49 Methylcyclohexane 0.68<br />

1,2,3-Trichlorobenzene N.D. t-1-Methyl-2-(4MP)cyclopentane 0.05<br />

Sum 1760 Sum 10.6<br />

Seasonal variations in concentration for various aromatic compounds<br />

Aromatic compounds Spring (ppb) Summer (ppb) Autumn (ppb) Winter (ppb)<br />

Benzene 2.50 1.70 N.D.* 0.84<br />

Toluene 5.99 2.43 1.57 7.25<br />

Ethylbenzene 9.80 0.39 0.25 1.19<br />

m,p-Xylene 8.88 0.45 0.34 1.82<br />

Styrene 1.94 0.11 N.D.* 1.18<br />

o-Xylene 6.27 0.28 0.20 1.45<br />

Bromobenzene N.D.* N.D.* N.D.* N.D.*<br />

n-Propylbenzene 0.90 0.03 N.D. 0.62<br />

1,2,4-Trimetylbenzene 4.80 0.16 0.09 2.82<br />

tert-Butylbenzene N.D. N.D. N.D. N.D.<br />

sec-Butylbenzene N.D. N.D. N.D. N.D.<br />

n-Butylbenzene N.D. N.D. N.D. 0.28<br />

Sum 41.1 5.55 2.45 17.5<br />

BTEX 33.4 5.25 2.36 12.6<br />

<strong>GERSTEL</strong><br />

Gas Sampler GS 1<br />

than the levels measured at the reference<br />

site. „Setting off firecrackers has a tremendous<br />

influence on air quality”, the scientists<br />

conclude.<br />

Professor Gon Ok and his colleagues<br />

have come to a clear and unequivocal conclusion:<br />

They are proposing changes in legislation<br />

that would restrict the use of fireworks<br />

in order to protect the health of people<br />

living in affected areas.<br />

<strong>GERSTEL</strong><br />

Gas Sampler GS 1<br />

In Germany, scientists involved are not<br />

ready to go quite that far. The approach taken<br />

is more cautious in spite of clear evidence<br />

as to the pollution caused by fireworks.<br />

The UBA on its homepage appeals<br />

to common sense: “Traditions and customs<br />

are part of our lives and should remain so.<br />

We are, however, asking you for help in limiting<br />

the amount of fine particulate matter<br />

released into our atmosphere on New Year’s<br />

Eve. Please reduce or completely eliminate<br />

your personal fireworks. In this way you will<br />

not only help improve the environment directly,<br />

you will help eliminate garbage from<br />

packaging material and spent fireworks<br />

while also reducing the amount of energy<br />

needed for fireworks production.”<br />

24<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Young In Scientific Co., Ltd.<br />

<strong>GERSTEL</strong> Distributor<br />

in South Korea<br />

Seoul/Head office<br />

547 Kang Nam-Ku, Shin Sa-Dong, Seoul, 135-890,<br />

Korea<br />

Tel. 82-2-519-7300<br />

Fax. 82-2-519-7400<br />

Daejeon Office<br />

3F 550-3 <strong>No</strong> Eun-Dong, Yu Sung-Gu,<br />

Daejeon-city, Korea<br />

Tel. 82-42-823-0025~6<br />

Fax. 82-42-823-0027<br />

Young In Scientific Co., Ltd. was founded<br />

in 1976 as a successor to its then<br />

parent company, GINSCO, General<br />

Instruments Company. Young In Scientific<br />

Ltd. belongs to the Young In group of<br />

companies in Korea, which provides complete<br />

customer solutions in most areas of<br />

Life Science as well as Chemical Analysis.<br />

Young In represents Agilent Technologies<br />

in Korea.<br />

Over the past 32 years, the company<br />

has focused on supplying and servicing<br />

Analytical Systems for laboratories in<br />

both industry and academia. The systems<br />

offered are based on advanced technologies<br />

and include solutions for QA/QC as<br />

well as R&D.<br />

Today, Young In has approximately 190<br />

employees in 7 offices. The head office in<br />

Seoul focuses on R&D and major Government<br />

institutes. The Central office focuses<br />

on R&D and the fine chemical (FineChem)<br />

business. The Southwestern office focuses<br />

on Biotechnology (Bio) and the Hydrocar-<br />

bon Processing Industry (HPI). The Southeastern<br />

office focuses on Import and Export<br />

products. In 2000, Young In was named official<br />

distributor for <strong>GERSTEL</strong> in Korea with<br />

exclusive selling rights. Young In has since<br />

then introduced many <strong>GERSTEL</strong> applications<br />

to the Korean market. As a result, sales<br />

of <strong>GERSTEL</strong> solutions increased by more<br />

than 250 % between 2003 and 2007. Many<br />

international companies such as Samsung<br />

and Hyundai Motor as well as universities<br />

and government departments are using<br />

<strong>GERSTEL</strong> solutions.<br />

Young In is one of the largest distributors<br />

of scientific, analytical, medical, electrochemical<br />

and process instrumentation<br />

in Korea (Source: AII Report). The success<br />

is based on a firm commitment to customer<br />

support and problem-solving, providing<br />

outstanding customer support in the fields<br />

of applications and service support.<br />

The vision of Young In is “To provide<br />

the most comprehensive, safe and reliable<br />

solutions to our customers”.<br />

Gwangju Office<br />

302 Dae Sung Hoe Gwan, 263-2 Shin An-Dong,<br />

Buk-Ku,<br />

Kwangju-city, Korea<br />

Tel. 82-2-51-553-6307<br />

Fax. 82-2-51-553-6308<br />

Yosu Office<br />

1F, 792-16 Hwa Jang-Dong, Yosu-city,<br />

Chonnam Provice, Korea<br />

Tel. 82-61-691-4601~2<br />

Fax. 82-61-691-4603<br />

Daegu Office<br />

194-18 Shin Chun 3-Dong, Dong-Ku,<br />

Daegu-city, Korea<br />

Tel. 82-53-741-5852~3<br />

Fax. 82-53-741-5854<br />

Ulsan Office<br />

4F, 693-8 Shin Jung 2-Dong, Nam-Ku, Ulsan-city,<br />

Kyungbuk Province, Korea<br />

Tel. 82-52-266-1260~1<br />

Fax. 82-52-266-1224<br />

Busan Office<br />

2F Dong Rae Bldg, 1428-44 On Chun 2-Dong,<br />

Dong Rae-Ku, Pusan-city, Korea<br />

Tel. 82-2-51-553-6307<br />

Fax. 82-2-51-553-6308<br />

Your contact<br />

Bernd Wiesend<br />

International Sales Manager<br />

<strong>GERSTEL</strong> GmbH & Co. KG<br />

Eberhard-Gerstel-Platz 1<br />

D-45473 Mülheim a. d. Ruhr, Germany<br />

Phone: + 49 (208) 7 65 03-0<br />

bernd_wiesend@gerstel.de<br />

Young In Scientifi c Co., Ltd. in South Korea, founded in 1976,<br />

has approximately 190 employees in 7 offi ces.


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Quality control and food safety<br />

Trout Malachite Green<br />

Even though malachite green (MG) is banned as a veterinary pharmaceutical for animals<br />

used for human consumption, authorities regularly fi nd residues of this toxic compound<br />

or its metabolites during routine checks of fi sh farms. Scientists from <strong>GERSTEL</strong>, TeLA and<br />

Agilent Technologies have succeeded in improving detection limits and in automating<br />

sample preparation for the determination of MG and its metabolite leucomalachite green<br />

(LMG) in fi sh products using automated SPE coupled with LC/Iontrap-MS.<br />

The triphenyl methane dye Malachite<br />

green (MG) is highly efficient in battling<br />

fungi, bacteria and various single<br />

cell parasites. MG, however, is under suspicion<br />

for being a human carcinogen and<br />

for causing damage to genetic material if it<br />

reaches the human organism through consumption<br />

of contaminated foods.<br />

Malachite green (MG) is traditionally<br />

administered as a fungicide in aquacul-<br />

<strong>GERSTEL</strong> MultiPurpose Sampler<br />

MPS with SPE<br />

ture, either as treatment or to prevent infections.<br />

Once inside the fish organism, MG<br />

is metabolized and reduced to leucomalachite<br />

green (LMG) which accumulates in<br />

fatty tissue. Fish that are contaminated with<br />

MG or LMG should not be consumed since<br />

they pose a health risk. In 2003,<br />

the EU Commission set threshold<br />

value of 2 μg/kg as the upper<br />

concentration limit<br />

for MG and LMG.<br />

Sample<br />

preparation<br />

A fish filet sample<br />

was homogenized<br />

with a water/acetonitrile<br />

mixture,<br />

extracted, centrifuged<br />

and the supernatant<br />

collected. The extraction<br />

procedure was repeated twice. The extracts<br />

were subsequently combined and concentrated<br />

before being taken up in a mixture<br />

of water and ethanol. Sample clean-up was<br />

performed using automated SPE in a GER-<br />

STEL MultiPurpose Sampler (MPS).<br />

LC/MS Method<br />

The MPS was integrated in an Agilent 1100<br />

LC/MS Iontrap System, consisting of a binary<br />

pump, a thermostated column compartment,<br />

a Diode Array Detector and an<br />

XCT+ Iontrap-MS. The LC/IT-MS was used<br />

in Electron Spray Ionization (ESI), positive<br />

ion mode. The injection volume used for all<br />

determinations was 5 μL. The separation<br />

was performed on a Zorbax SB-C18 column<br />

(50 x 2.1 mm, 1.8 μm) with a flow rate<br />

of 0.6 mL/min in gradient mode (Eluate A:<br />

0.1 % formic acid, eluate B: acetonitrile).<br />

The column was kept at 50 °C. The complete<br />

26<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008


<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide Application<br />

Malachite green<br />

system control, including sample preparation,<br />

sample introduction, LC/MS analysis<br />

and data handling, was performed using the<br />

<strong>GERSTEL</strong> MAESTRO Software integrated<br />

with the Agilent Technologies ChemStation<br />

Software (Rev. A10.03).<br />

Mass spectra of malachite green (MG)<br />

and leucomalachite green (LMG)<br />

Results and Discussion<br />

Malachite green (MG) and its metabolite<br />

leucomalachite green (LMG) are easily ionized<br />

using Electron Spray Ionization (ESI)<br />

in positive ion mode. MG differs from LMG<br />

in that it forms a doubly charged ion (m/z<br />

166) in addition to the single charged molecular<br />

ion [M+H] + . This is due to the nonplanar<br />

sterical organization of the central<br />

carbon in the leuco form. In MS 2 mode,<br />

the MG-precursor ion forms a product ion<br />

(m/z 313), while the doubly charged LMG<br />

precursor also forms a doubly charged fragment.<br />

The transition can be used for highly<br />

sensitive determination of LMG. Using<br />

these transitions, limits of determination of<br />

0.5 μg/kg for MG and 0.05 μg/kg for LMG<br />

can be achieved.<br />

Automated SPE directly coupled with<br />

the LC/MS system provides recoveries as<br />

high as 90 % and excellent reproducibility<br />

for the SPE step. Additionally, automated<br />

SPE reduces the time required for<br />

sample preparation by 50 % compared<br />

with the manual procedure.<br />

Conclusion<br />

The described automated SPE/LC/IT-MS<br />

system enables automated sample cleaning<br />

and sample preparation followed directly<br />

by injection and analysis of the generated<br />

extracts. The sample preparation method is<br />

easily adapted to individual requirements<br />

by selecting the desired steps from a simple<br />

menu by mouse-click. The entire method<br />

including sample introduction, LC/MS<br />

analysis and data handling steps is performed<br />

using one integrated method and<br />

one sequence table from within the Agilent<br />

Technologies ChemStation Software.<br />

The sample clean-up steps ensure the<br />

removal of interfering matrix residue leading<br />

to significantly better signal to noise ratios<br />

and improved detection limits for MG<br />

and LMG in the MS system. The method is<br />

rugged and stable. RSDs range from 3.4 %<br />

to 5.3 % while recoveries are in the range<br />

from 89.5 % to 90.3 %.<br />

Chemical structure of malachite green<br />

and leucomalachite green<br />

Chemically, malachite green belongs<br />

to the group triphenyl methanes<br />

and is mainly used as a<br />

synthetic colorant, for example<br />

in lacquers.<br />

Malachite green (MG) is<br />

also a highly effective disinfectant,<br />

capable of fi ghting various parasites,<br />

such as fungi, germs and single cell organisms<br />

that attack fi sh and fi sh roe.<br />

For this reason, MG is often used in fish<br />

aquaria, especially against white dot<br />

disease caused by the ichthyophthirius<br />

multifiliis parasite.<br />

Malachite green is suspected of being<br />

a human carcinogen and of causing<br />

damage to human genetic material. To<br />

avoid any health risk to consumers, MG<br />

has been banned from use in animals<br />

destined for human consumption within<br />

the European Union (EU).<br />

In the German state of Baden-Wuerttemberg<br />

a total of 336 samples were<br />

analyzed for triphenyl-methane compounds<br />

in 2005. Samples were taken<br />

from salt and fresh water fish as<br />

well as from trout roe. Forty four trout<br />

samples and one catfish sample were<br />

found to contain leucomalachite green<br />

(LMG), the main metabolite of MG. The<br />

concentrations found ranged from 2 to<br />

over 100 μg/kg. One trout sample was<br />

found to also contain MG at 1.5 μg/kg.<br />

The large number of tests and “positives”<br />

resulted from testing all basins<br />

in three fish-producing companies after<br />

random tests had revealed traces<br />

of MG. All cases where samples were<br />

found to contain residues of LMG were<br />

subsequently officially pursued.<br />

(Source: Monitoring of food products,<br />

consumer products, cosmetics<br />

and animal feed. Annual report, Ministry<br />

of food and agriculture, Baden-<br />

Württemberg, Mail box 10 34 44, 70029<br />

Stuttgart, Germany).<br />

MS 2 spectra of MG and LMG<br />

Calibration curve for leucomalachite green<br />

The Authors<br />

<strong>No</strong>rbert Helle, Ph.D.<br />

and Martina Bohlje<br />

(TeLA GmbH, Bremerhaven)<br />

Jürgen Wendt, Ph.D.<br />

(Agilent Technologies, Waldbronn)<br />

Frederick D. Foster (<strong>GERSTEL</strong>, Inc.,<br />

Baltimore, USA)<br />

Carlos Gil (<strong>GERSTEL</strong> GmbH & Co. KG,<br />

Mülheim an der Ruhr)<br />

<strong>GERSTEL</strong> <strong>Solutions</strong> Worldwide – February 2008<br />

27


You may think you know what<br />

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included in standard software<br />

- Internal standard addition<br />

- Dilution and derivatization<br />

- Sample Prep by Mouse-Click,<br />

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- Eliminates SPME fi ber stress<br />

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Highest sample capacity<br />

- 1,296 x 2 mL vials<br />

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G L O B A L A N A L Y T I C A L S O L U T I O N S<br />

<strong>GERSTEL</strong> GmbH & Co. KG<br />

Eberhard-Gerstel-Platz 1<br />

45473 Mülheim an der Ruhr<br />

Germany<br />

+49 208 - 7 65 03-0<br />

+49 208 - 7 65 03 33<br />

gerstel@gerstel.com<br />

www.gerstel.com<br />

<strong>GERSTEL</strong>, Inc.<br />

Caton Research Center<br />

1510 Caton Center Drive,<br />

Suite H<br />

Baltimore, MD 21227<br />

USA<br />

+1 410 - 247 5885<br />

+1 410 - 247 5887<br />

info@gerstelus.com<br />

www.gerstelus.com<br />

<strong>GERSTEL</strong> AG<br />

Enterprise<br />

Surentalstrasse 10<br />

6210 Sursee<br />

Switzerland<br />

+41 41 - 9 21 97 23<br />

+41 41 - 9 21 97 25<br />

gerstel@ch.gerstel.com<br />

www.gerstel.de<br />

<strong>GERSTEL</strong> K.K.<br />

2-13-18 Nakane, Meguro-ku<br />

152-0031 Tokyo<br />

Dai-Hyaku Seimei Toritsudai<br />

Ekimae Bldg 2F<br />

Japan<br />

+81 3 57 31 53 21<br />

+81 3 57 31 53 22<br />

info@gerstel.co.jp<br />

www.gerstel.co.jp<br />

Subject to change. <strong>GERSTEL</strong> ® , GRAPHPACK ® and TWISTER ® are registered trademarks of <strong>GERSTEL</strong> GmbH & Co. KG.<br />

Printed in Germany · 0208b · © Copyright by <strong>GERSTEL</strong> GmbH & Co. KG

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