Comparison of GC and OxiTop Analysis of Biogas Composition Produced by Anaerobic Digestion of Glucose in Cyanide Inhibited Systems

The purpose of this study was to compare the composition of the biogas produced by the anaerobic degradation of glucose with or without the addition of cyanide (32.0 mg L-1) during the digestion process using the qualitative OxiTop method and the quantitative gas chromatography (GC). For the non-inhibited systems the biogas composition obtained from OxiTop was in good correlation with the results obtained using gas chromatography analysis. On the other hand, a great difference was observed for the biogas composition of the inhibited system. We have shown that the necessary assumption, when using the OxiTop method, that the residual gas after carbon dioxide elimination was only methane, was not accurate for the inhibited reaction system.