• 作者：D. Fabbri ^A1 ; M. Mongardi ^A2 ; L. Montanari ^A3 ; G. C. Galletti ^A1 ; G. Chiavari ^A1 ; R. Scotti ^A4
• 刊名：Fresenius' Journal of Analytical Chemistry
• 出版年：1998
• 出版时间：October 1998
• 年：1998
• 卷：362
• 期：3
• 页码：299-306
• 全文大小：151 KB

Abstract The chemical structure of humins (HUs) and humic acids (HAs) of terrestrial and marine environments was investigated by cross-polarization magic angle spinning ¹³C-nuclear magnetic resonance spectroscopy (CP/ MAS ¹³C-NMR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Samples of HUs and HAs were obtained from sediments of the Adriatic Sea, the Lagoon of Ravenna (Adriatic Sea) and the Bubano Lake as well as from an agricultural soil. HUs displayed pyrograms and NMR spectra different from those of related HAs. According to NMR spectra HUs were more aliphatic and contained fewer carboxyl groups than HAs, while pyrolysates of HUs were characterized by higher levels of products arising from carbohydrates and lower levels of lignin methoxyphenols with respect to HAs. The relative content of paraffinic carbons determined by NMR was in good agreement with the relative abundance of unbranched aliphatic hydrocarbons released by pyrolysis. Both techniques evidenced the importance of polymethylene structures in HUs.