Evaluating the accuracy and reliability of compound-specific carbon isotopic analysis using gas chromatography-combustion-isotope ratio mass spectrometry with the addition of a reduction furnace.

The addition of an independent reduction furnace had no significant effect on the δ C of n-alkanes and fatty acid methyl esters, but it had a significant effect on the δ C of nitrogen-containing compounds. It is suggested that GC IsoLink needs an independent reduction furnace to effectively eliminate the interference of NO on CO isotopic determination to improve the accuracy of δ C for nitrogen-containing compounds.