Analysis of branched-chain fatty acids in humic substances as indices for compost maturity by pyrolysis-gas chromatography/mass spectrometry with tetramethylammonium hydroxide (TMAH-py-GC/MS)

作者：Fukushima Masami^*; Tu Xuefei; Aneksampant Apichaya; Tanaka Atsushi

来源：Journal of Material Cycles and Waste Management, 2018, 20(1): 176-184.

DOI：10.1007/s10163-016-0559-z

• Composting
• Humic substances
• Humification
• TMAH-py-GC/MS
• Branched-chain fatty acids

Parameters that affect the degree of humification for humic substances (HSs) are deeply related to the maturity of the compost. In general, the matured composts contain HSs with a higher degree of humification. In addition, microbial activities during composting are also one of the indices for compost maturation. Branched-chain fatty acids are metabolites as the result of microbial activities in a soil environment. Such branched-chain fatty acids, regarded as humic precursors, are incorporated into HSs during the composting process. To determine whether branched-chain fatty acids in HSs can be used as biomarkers during composting processes or not, HSs were extracted from three types of composts with the different maturation, and the branched-chain fatty acids in the HSs were analyzed by pyrolysis-gas chromatography/mass spectrometry with tetramethylammonium hydroxide (TMAH-py-GC/MS). HSs with a higher degree of humification (higher aromaticity and lower molecular weight) contained higher levels of branched-chain fatty acids. These results show that branched-chain fatty acids in HSs from matured compost samples can be used as biomarkers, which indicate the history of microbial activities during overall composting process.

• 出版日期2018-1