Soil hydrolysates

J.L. Young and J.L. Mortensen, Soil nitrogen complexes, I, Chromatography of amino compounds in soil hydrolysates, Ohio Agr. Exp. Sta. Res. Circ. 61 (1958) 1-18. 

New developments in the separation of mono- and di-saccharides on anion-exchange columns using alkaline eluants and pulsed amperometric detection have been reported. The major monosaccharides (Glc, Gal, Man, Ara and Xyl) in soil hydrolysates have been determined by h.p.l.c. on a polystyrene-based Pb " -form cation-exchange column. Minor sugars (Rha and Fuc) co-eluted with major components. ... 

The individual amino sugars in the soil hydrolysates may be separated... 

The soluble N in the soil hydrolysate which cannot be accounted for... 

BENZING-PURDIE L. 1981. Glucoscimine and galactosamine distribution in a soil as determined by gas liquid chromatography of soil hydrolysates. Effect of strength and cations. Journal of the Soil Science Society of America Proceedings, 45, 66-70. 

FRENEY J.R., STEVENSON F.J. and BEAVERS A.H. 1972. Sulphur-containing amino acids in soil hydrolysates. Soil Science, 114, 468-476. 

Calcium cyanamide (lime nitrogen) has been used as a fertiliser (6). It hydrolyses ia moist soil to produce ammonia ... 

Animals, including humans, cannot synthesise all the different amino adds they need and thus require them in their diet. These amino adds are called the essential amino acids. Proteins in food are hydrolysed in the digestive tract and the resulting amino acids are reassembled into proteins within the animal s cells. All animals are ultimately dependent on plants for protein, as it is plants that create protein by combining inorganic nitrogen from the soil (as nitrate) with organic molecules derived from carbon from the atmosphere (as CO2). 

A variety of phosphoric acid triesters and their derivatives are used as pesticides. Although there are no natural phosphorotriesters, those artificial ones undergo decomposition in the soil, implying that some microorganisms exist which are capable of hydrolysing them. The first report on a stereoselective enzymatic phos-photriester hydrolysis was pubhshed in 1973, when Dudman and Zerner succeeded... 

The major metabolite of pyraflufen-ethyl in plants and soils is E-1 (ester hydrolysate). E-2 (phenol derivative) and E-3 (methylated E-2) are also detected as major metabolites in soils. The target analytes are considered to be pyraflufen-ethyl at least in plant materials, pyraflufen-ethyl, E-1, E-2 and E-3 in soils and pyraflufen-ethyl and E-1 in water samples. 

Dilute acid (0.5 M- 2.5 M H2S04) - extractable C or carbohydrate - C have also been used as indicators of soil organic matter status (Angers and Mehuys 1989 Chan and Heenan 1999 Shepherd et al. 2001). The acid hydrolysable fraction generally accounts for about 20-40% of total organic C (Rovira and Vallejo 2002) and 65-85% of the total soil carbohydrate pool (Puget et al. 1999). 

N-methylcarbamate and N,N -dimethylcarbamates have been determined in soil samples by hydrolyses with sodium bicarbonate and the resulting amines reacted with 4-chloro-7-nitrobenzo-2,l,3-Oxadiazole in isobutyl methyl ketone solution to produce fluorescent derivatives [81]. These derivatives were separated by thin layer chromatography on silica gel G or alumina with tetrahydrofuran-chloroform (1 49) as solvent. The fluorescence is then measured in situ (excitation at 436 nm, emission at 528 and 537nm for the derivatives of methylamine and dimethylamine respectively). The... 

AIs Beispiel fur eine der Formen, in welcher sich die Konstitution der Alkylgruppen auf das Reaktionsvermogen bemerkbar macht, soil die Hydrolyse der Alkylbromide durch OH -Ionen in waBrigem Alkohol betrachtet werden. Die Reaktion verlauft nach der Gleichung... 

Abiontic, involving free extracellular enzymes or solubilizing agents, enzymes bound to soil surfaces, enzymes within dead or non-proliferating cells, or enzymes associated with dead cell fragments. Extracellular enzymes are important in the initial stages of organic matter oxidation, in which polysaccharides and proteins are hydrolysed to soluble compounds that can be absorbed by microbial cells and further oxidized in biotic processes. 

Thallium occurs in soils in both -p3 and -pl oxidation states. Tl + behaves much like Al +, but hydrolyses even more readily and insoluble Tl(OH)3 is formed... 

Primarily, Fe is released from the lithosphere into surface environments including soils by veathering of primary silicate and sulphide minerals (Tab. 16.1). In the presence of O2 and H2O and in the common pH range (>2) of surface environments, the released Fe" is oxidized to Fe " which in turn, is immediately hydrolysed to form Fe " oxides and oxide hydroxides. For Fe" silicates these reactions involve breakage of an Fe"-0-Si bond and the formation of Fe "OH and SiOH groups. For example, goethite may be formed from the oxidation and hydrolysis of olivine (fayalite) through the reaction ... 

Cohen and Wheals [334] determined ten hydrolysable carbamate and substituted urea herbicides in soil in amounts down to 0.001-0.05 ppm. In this method, a solution of the herbicide-containing extract of the soil is spotted onto a silica gel G plate and developed with hexane acetone (5 1). The plate is sprayed with 1-fluoro-l,4-dinitrobenzene in acetone and heated to 190 °C to produce the 2,4-dinitrophenyl derivative of the herbicide amine moiety acetone extracts of the areas of interest are subjected to gas chromatography. 

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