Nitrogen / Protein Determination by Combustion

FP628
Nitrogen / Protein
Determination by Combustion
Rev 1 - 6/8/11

Presentation Outline
• LECO Background
• N Determination
• FP628
– Theory of Operation
– Specifications
– Advantages
– Software
– Data

LECO Background
• Privately owned U.S. Company for over 70 years
• Headquartered in Saint Joseph, MI
• Diverse Instrumentation offerings
– Organic and Inorganic Elemental Analysis
– Mass Spectrometry (TOF)
– Metallography
– Microscopy and Image analysis
Environmental
Food
Energy
Metals
Mining
• 25 LECO subsidiaries representing over 100 countries

N / Protein Determination
• Quantitative Analysis
– Nutritional labeling (protein) for foods and feeds
– Material characterization - education/research, commercial and regulatory
– Soil/plant science
• Process and Quality Control
– Grade and value for feeds
– Food, agricultural and chemical processing
• Milling applications (starch, flour, oilseeds)
• Chemical and Specialty materials processing (resins, adhesives, etc)

Techniques for Determining Nitrogen

FP628
• Vertical quartz furnace tube with a maximum temperature of 1050°C
• Sample mass 50mg up to ~1g
• Tin capsules or foils used to encapsulate sample and attain high combustion
temperature ~1800°C
• Reticulated crucible collects ash from sample and tin cap or foil

FP628 Theory of Operation
• A sample is weighed into a foil or capsule and loaded into autoloader

FP628 Theory of Operation
• Sample is loaded into purge chamber
removing atmospheric gas
• Sample introduced to furnace

FP628 Series Theory of Operation
• Combustion gases are swept from the
furnace into the thermo electric cooler
• Moisture efficiently removed without the
use of chemical anhydrone

FP628 Theory of Operation
• Combustion gas is swept onto the
combustion gas collection and aliquot
collection system

FP628 Theory of Operation
• Aliquot gas is swept through a reduction reagent tube then passes through Lecosorb
and anhydrone reagent tube

FP628 Theory of Operation
• The aliquot gas passes through a thermal conductivity cell for nitrogen detection

Thermal conductivity table

FP628 Specifications
• Instrument Range
– Nitrogen 80ppm to 100% Nitrogen @ 500mg
• Precision Range
– Nitrogen 0.02 mg Nitrogen or 0.5% RSD (whichever is greater)
• Analysis Time ~4.5 minutes nominal
• Sample Mass
– N up to ~1g, 500 mg nominal
• Cost per Analysis
– ~54p regardless of sample weight, type, moisture

FP628 Series Specifications (cont.)
• Detection Technique
– Nitrogen Thermal Conductivity (TC Cell) Detector
• Furnace Resistance Primary and Secondary up to 1050 o C max
• Autoloader 30-position, expandable up to 120
• Electrical Power Requirements
– Instrument 230 V~, 50/60 Hz, single phase, 12A

Instrument Range Concentration Calc
• FP628 range:
– 500 mg sample mass
• Nitrogen (80ppm to 10%)
– Low end = (0.04 mg N / 500 mg sample) * 100 = 0.08% or 80 ppm N
– High end = (50 mg N / 500 mg sample) *100 = 10% N

FP628 Advantages
• Analysis Time Throughput
– Analysis time
• FP628 is the fastest macro combustion instruments in the market
• FP628 Series analysis time is ~4.5 minutes
• Whole gas analysis techniques using chromatographic separation or purge
and trap approached typically have 2 times longer analysis times
• Competitive whole gas instruments analysis times are dependent on
element configuration and sample mass (more elements and or sample
mass = longer time…)
Samples/Hour
• FP628 Series 14
• Competitor N model 7

FP628 Advantages
• Low cost-per-analysis
– Exclusive use of Oxygen within Combustion Furnace results in:
• Ensures complete combustion and superior recovery of elements
• Speeds combustion
• Allows for use of macro sample mass
• Eliminates the need for other reagent oxidizers within combustion system
– Ballast and Aliquot Combustion Gas Handling system
• Allows for the exclusive use of pure oxygen in the furnace
• Eliminates treating the whole combustion gas with CO2 scrubbers and
reduction reagents
• Significantly extends lifetime of CO2 scrubber and reduction reagents

FP628 Advantages
• Ability to determine carbon hydrogen and nitrogen in macro samples of various
organic matrices under the same method and conditions
• Multiple methods and calibrations are not required to compensate for poor
combustion conditions
• Allows system to analyze heterogeneous samples with better precision and accuracy
– Plant Tissues
– Feeds
– Flour
– Etc.

FP628 Series Software
• LECO Windows ® -based operating software
– Seamless management of data and
detector plots
– Integrated control charts and statistical
calculations

FP628 Series Software
• LECO Windows-based operating software
– Monitor real-time internal component
readings
– Expanded interactive diagnostic
screens aiding
• Troubleshooting
• Improve serviceability

FP628 Series Software
• LECO Windows-based operating software
– Simplified data handling with convenient storage and customizable reporting and
data exporting capabilities
– User definable fields for automatic calculations
– Compatible with various Laboratory Information Management Systems (LIMS)

FP628 Calibration
Wide Dynamic Range Calibration
– ~50 mg to ~350 mg EDTA
• 1.0 to 33.5 mg N
• Linear curve type

CN628 Blanks
• Low Consistent Blank
– ~3 ppm Nitrogen Std Dev

FP628 Data
502-563 Corn Flour Sample Data
– ~250 mg sample mass
– EDTA Calibration
– Cert values:
• 1.46 +/- 0.02 % N

FP628 Data
502-563 Corn Flour Sample Data
– ~250 mg sample mass
– EDTA Calibration
– Cert values:
• 1.46 +/- 0.02 % N

FP628 Data
Glycine Solution Sample Data
– ~300 mg sample mass
– EDTA Calibration
– Expected value:
• 0.1 % N

FP628 Data
Ammonium Sulfate Sample Data
– ~50 mg sample mass
– EDTA Calibration
– Theoretical value:
• 21.2 % N

CHN628 Series
Elemental Analysis by Combustion
Unparalleled Capabilities

Leco Macro Nitrogen Determination
• Vertical and horizontal furnace designs utilize the LECO combustion approach resulting in:
− Rapid analysis time (4 minutes)
− Extended reagent lifetimes and instrument uptime
− Ability to handle macro samples up to ~3g
− Low cost-per-analysis
− Complies with AOAC, ASTM, ISO, AACC AND ASBC approved methods

Leco Instruments UK Ltd
Thanks for Listening
Michael Reaney
If you require further information please feel free to contact the Leco stand