Carbon Hydrogen Nitrogen
Carbon, Hydrogen and Nitrogen AnalysisAnalysis for carbon, hydrogen and nitrogen is conducted in an elemental analyzer that burns a small portion of sample in an oxygen atmosphere to create the combustion byproducts CO2, H2O and N2 (or NOx). The gases are then separated and quantified by either an infrared cell or a thermal conductivity detector. Results are reported in wt % of the corresponding element.
Sample PreparationSamples are prepared by weighing a sample portion into a capsule (typically made of tin foil), carefully crimping the capsule and then loading it into an auto sampler. Typical masses taken for this test are between 1 and 5 mg, though more may be taken for some instruments. The autosampler drops the sample capsule into a furnace where the combustion occurs. In the case of samples that exhibit poor recovery of carbon, hydrogen or oxygen, a combustion aid, such as Vanadium Pentoxide, may be added to the sample before the capsule is crimped. Presence of this combustion aid improves the overall combustion of the sample and may improve recovery.
MethodsGalbraith Laboratories employs four different analytical methods for the determination of CHN. The methods are largely aligned with different models of Elemental Analyzers. Each of Galbraith’s methods are based on industry methods, but have extra QC requirements embedded to ensure the accuracy of results.The methods are indicated below along with links to each method summary: