Nuclear Magnetic Resonance and Diffuse-Reflectance Infrared Fourier Transform Spectroscopy of Biosolids-Derived Biocolloidal Organic Matter

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• 作者：J.-D. Mao ; L. S. Hundal ; K. Schmidt-Rohr ; and M. L. Thompson
• 刊名：Environmental Science & Technology
• 出版年：2003
• 出版时间：May 1, 2003
• 年：2003
• 卷：37
• 期：9
• 页码：1751 - 1757
• 全文大小：213K
• 年卷期：v.37,no.9(May 1, 2003)
• ISSN：1520-5851

文摘

We extracted the acid-soluble portion of municipalbiosolids, fractionated it by both molecular weight (MW)and hydrophobicity, and used various solid-state nuclearmagnetic resonance (NMR) methods and diffuse-reflectanceinfrared Fourier transform (DRIFT) spectroscopy tocharacterize the fractions. Spectroscopic characterizationof the MW components of the biosolids-derived organicmatter fractions revealed the presence of functionally distinctgroups of compounds. Quantitative ¹³C NMR, CH spectralediting, and several two-dimensional NMR experiments showthat the high-MW hydrophilic fraction in particular isstructurally simple, consisting predominantly of N-acetylatedpolysaccharides, perhaps derived from bacterial peptidoglycans. In the high-MW hydrophobic fraction, aromaticcompounds were present in addition to the N-acetylatedpolysaccharides. Infrared spectroscopy confirmed thathydrophilic fractions were dominated by carbohydrates andindicated that the lower-MW fractions lacked amidemoieties. Complementary interpretations of the DRIFT andNMR spectra improved our knowledge of the componentsseparated by this fractionation scheme, allowing bettercharacterization of biosolids organic matter. Moreover,fractionation based on both MW and hydrophobicity mayprove useful in detailed characterization of the structure ofbiosolids-derived organic matter and other similarlyheterogeneous natural organic matter in soils and sediments.