Humin distributions

H NMR 38,39,42, 50-55 Hole capacity constant 205 Homogeneous distribution of correlation times 37 Humic acids 17 Humidity of plastics 119 Humins 17 Hydrogen bond 200 Hydrophilic 191, 194, 206... 

In the seven lakes studied by Yamamoto (1983), amino acid distribution of fulvic acid, humic acid, and humin resembled each other. However, after detailed examination of amino acid distribution, the following regularities were found to exist in almost all humic substances studied ... 

Fatty acids in humin from Lake Haruna sediments were analyzed for the fraction obtained by solvent (benzene/methanol 6 4) extraction followed by saponification 2N KOH aqueous solution at 200°C for 3 hours) extraction (Yamamoto and Ishiwatari, 1981). The fatty acids were composed of normal C12-C30 saturated monocarboxylic acids (maximum at Cig), unsaturated (Cie and Cis), and branched (C13, C15, and Cn) monocarboxylic acids. The fatty acid distribution in humin resembled that in humic acid. Total fatty acids accounted for 1.0% of the humin and probably originated from algae, bacteria, and higher plants. 

A portion of these biochemical compounds may be associated with the extracted humic substances. However, as already described, the humin which had been hydrolyzed by 6N HCl at 110°C for 24 hours gave essentially the same oxidative (KMn04) degradation products (aliphatic C4-C14 a,co-dicarboxylic acids as major products) as untreated humin. Moreover, stepwise (eight steps) oxidative (KMn04) degradation of humin produced similar degradation products (aliphatic Cs-C 8 monocarboxylic and C5-C16 a,co-dicarboxylic acids and small amounts of benzenecarboxylic acid Machihara and Ishiwatari, 1980). These facts indicate that the major part of humin forms aliphatic structures with biochemical compounds distributed uniformly in the humin matrix. These compounds are firmly linked within the humin matrix by unknown bonds. 

The distribution pattern of a,w-dicarboxylic acids for lipids resembled those for humic acid and humin (Fig. 3). This fact clearly indicates the common origin for the polymethylene chains in lipids, humic acid, and humin, which means that phytoplankton-derived lipids actively took part in the formation of humic acid and humin. The relative abundance of polymeth-ylene chains in lipids and humic substances was estimated on the assumption that the yield of production of aliphatic acids from polymethylene chains by alkaline permanganate oxidation was the same for these organic fractions. The following estimations resulted 42% (% of the total amount of polymethylene chains in the sediment) for humin, 38% for lipids, 19% for humic acid, and 1% for fulvic acid. 

Table 5 presents data on the distribution of nitrogen in humic acids, fulvic acids, and humin extracted from tropical soils. Especially noteworthy are the relatively high proportions of amino acid nitrogen in all humic fractions, and the unusually high percentages of total nitrogen identified. Humin is especially rich in amino sugars. 

The most striking features of the amino acid composition of the three humic preparations (Table 6) are (1) the high concentrations of acidic amino acids in the fulvic acids (2) the relatively low concentrations of basic and some neutral amino acids (phenylalanine, tyrosine, leucine, and isoleucine) in the fulvic acids and (3) the accumulation of cysteic acid in the fulvic acids. The distributions of amino acids in the humic acids and humin are quite similar. 

Selective extraction was used to operationally determine the quantitative and qualitative distributions of PCB 8 and saturated hydrocarbons among free lipid (FL), humic acid (HA), and humin (HU) fractions of four contaminated estuarine sediments. In all samples, over 90% of the total sedimentary PCB s and hydrocarbons were extracted with FL fractions. Bound (HA and HD) and free assemblages of these compounds may have derived from different sources. Two polar, chlorinated pollutants also detected In this study, hexachlorophene (HCP) and pentachlorophenol (PCP), were proportionately more concentrated In bound fractions than the non-polar compounds HCP was detected only In HA fractions and was probably chemically hound to refractory organic matter. Selective extraction Is a promising technique for Investigating strongly bound polar pollutants, such as HCP, which apparently are not recovered by conventional solvent extraction. 

Fig. 11 N2 adsorption-desorption isotherms (a) and pore size distribution curves from the adsorption branch (b) of mesoporous silica spheres. Reprinted from Yurong Ma, Limin Qi, liming Ma, Yongqing Wu, Ou Liu, and Humin Cheng Large-pore mesoporous silica spheres Synthesis and application in HPLC CoUoids Surf A Physicochem. Eng. Asp., 229 (2003) 1-8, Copyright 2003 with permission from Elsevier Science...

Amino acid analyses of horse liver catalase have been carried out by Theorell and Akeson (78) and by Bonnichsen (13), who compared these values with those obtained on horse blood catalase. Bonnichsen s results largely confirmed the earlier values of Theorell and Akeson. Furthermore, he analyzed the catalase for glutamic and aspartic acids and cystine. Horse liver catalase, according to Bonnichsen, contains 3.86% histidine, 8.9% arginine, 7.1% lysine, 10.3% glutamic acid, 16.5% aspartic acid, and 1.85% cystine (mean values). The values for the horse blood catalase were, within the limits of error, the same. This applies to the nitrogen distribution on the fractions humin, anodic, neutral, and cathodic nitrogen as well. 

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