GERSTEL Solutions No. 8 (pdf; 5,56 MB)
GERSTEL Solutions No. 8 (pdf; 5,56 MB)
GERSTEL Solutions No. 8 (pdf; 5,56 MB)
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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
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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 />
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+49 208 - 7 65 03 33<br />
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www.gerstel.com<br />
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+1 410 - 247 5885<br />
+1 410 - 247 5887<br />
info@gerstelus.com<br />
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