Molecular Characterization of Compost at Increasing Stages of Maturity. 1. Chemical Fractionation and Infrared Spectroscopy
详细信息 查看全文
- 作者：Riccardo Spaccini ; Alessandro Piccolo
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：March 21, 2007
- 年：2007
- 卷：55
- 期：6
- 页码：2293 - 2302
- 全文大小：363K
- 年卷期：v.55,no.6(March 21, 2007)
- ISSN：1520-5118
文摘
Composted organic biomasses at 60, 90, and 150 days of maturity were studied for changes inmolecular composition. Compost samples were subjected to a mild sequential fractionation basedon (1) organic solvent extraction, (2) transesterification with boron trifluoride in methanol (BF3-CH3OH), and (3) methanolic alkaline hydrolysis (KOH-CH3OH). The general chemical variations incompost residues following fractionation were monitored by DRIFT spectroscopy, whereas themolecular components separated along the fractionation steps were identified by GC-MS. DRIFTspectra suggested a progressive decrease of biolabile compounds such as alkyls, carbohydrates,and proteinaceous materials with compost maturity. Extraction of unbound components in an organicsolvent indicated a considerable reduction of linear and branched alkanoic acids, both saturated andunsaturated, n-alkanes, and n-alkanols with enhancing compost maturity. Extracts of weakly boundmolecules by transesterification revealed a decrease, with compost maturity, of components frommore recalcitrant plant polyesters, such as 
-, di-, and trihydroxy acids, dioic acids, and n-alkanols.Extracts of strongly bound molecules by alkaline hydrolysis indicated a lower decrease of the samecomponents, suggesting their reduced availability when in stable hydrophobic domains of progressivelymature compost. The largest decrease in molecular components occurred when compost wasstabilized from 60 to 90 days, whereas its composition did not significantly vary after stabilization at150 days. The molecular structures of a number of steroids and terpenes appeared to be lesssusceptible to transformation with composting maturity, thereby resulting as useful biomarkers totrace the fate of composted organic matter in the environment. This work showed that a detailedmolecular characterization of compost by a stepwise chemical fractionation enables the evaluationof compost maturity and origin of composted biomasses, as well as the identification of environmentaltracers.
-, di-, and trihydroxy acids, dioic acids, and n-alkanols.Extracts of strongly bound molecules by alkaline hydrolysis indicated a lower decrease of the samecomponents, suggesting their reduced availability when in stable hydrophobic domains of progressivelymature compost. The largest decrease in molecular components occurred when compost wasstabilized from 60 to 90 days, whereas its composition did not significantly vary after stabilization at150 days. The molecular structures of a number of steroids and terpenes appeared to be lesssusceptible to transformation with composting maturity, thereby resulting as useful biomarkers totrace the fate of composted organic matter in the environment. This work showed that a detailedmolecular characterization of compost by a stepwise chemical fractionation enables the evaluationof compost maturity and origin of composted biomasses, as well as the identification of environmentaltracers.