Comparison between sampling and analytical methods in characterization of pollutants in biogas

Different sampling methods involving the collection of biogas by Tedlar bags or adsorption tubes, and different GC–MS injection systems, loop injection or cold trap injection (with bags or by tube desorption), were compared to establish the best method to determine the minority compounds in biogas from sewage treatment plants (STPs). A study of parameters is included, such as the stability of compounds in Tedlar bags or cartridges and the adsorption effect of some less volatile compounds in the thermal desorption system (TD). timized methods allowed to determine most compounds at low mg m−3 levels. Among them, maximum values of D5 (4.84 mg m−3), decane (95–118 mg m−3) and H2S (2223 mg m−3) were found in biogas samples.