Publisher Summary This chapter presents a procedure for the calorimetric analysis of sugars for the identification and determination of small quantities of carbohydrates obtained from biological materials. In general, such tests have been devised by heating aqueous solutions of the sugar with a strong acid, thereby converting it to furfural or a derivative of furfural. A color is then produced by the addition of an organic developer such as indole, orcinol, diphenylamine, or carbazole. Many of the reagents commonly employed for the determination of a specific class of sugars are suitable, with slight modifications, to measure total carbohydrates. Thus, orcinol, carbazole, indole, and diphenylamine have all been used for this purpose. Although these reactions logically require a separate classification, therefore they are discussed individually to prevent unnecessary duplication. For the determination of inulin diphenylamine reaction is employed, which is based on the Ihl-Pechmann reaction for fructose and is not to be confused with the diphenylamine test for DNA. In arsenomolybdate method of Nelson a colorimetric determination of the reaction product replaces the conventional iodometric titration of the reduced copper found in the Somogyi reagent, thus facilitating the handling of serial assays. In addition to the methods discussed in the chapter for the determination of pentoses, there are several alternate procedures which may be of value under special circumstances. The more important of these seem to be the methods of Roe and Rice and of Tracey employing p-bromoaniline and aniline, respectively, as the color-producing agent. These reactions are appreciably less affected by the presence of hexoses and uronic acids than is the case with orcinol.

[12] Colorimetric analysis of sugars

Polysaccharides in colon-specific drug delivery

The relationships between the denitrification capacities of 17 surface soils and the amounts of total organic carbon, mineralizable carbon, and water-soluble organic carbon in these soils were investigated. The soils used differed markedly in pH, texture, and organic-matter content. Denitrification capacity was assessed by determining the N evolved as N2 and N2O on anaerobic incubation of nitrate-treated soil at 20°C for 7 days, and mineralizable carbon was assessed by determining the C evolved as CO2 on aerobic incubation of soil at 20°C for 7 days. The denitrification capacities of the soils studied were significantly correlated (r = 0·77∗∗∗) with total organic carbon and very highly correlated (r = 0·99∗∗∗) with water-soluble organic carbon or mineralizable carbon. The amount of nitrate N lost on anaerobic incubation of nitrate-treated soils for 7 days was very closely related (r = 0·999∗∗∗) to the amount of N evolved as N2 and N2O.

The work reported indicates that denitrification in soils under anaerobic conditions is controlled largely by the supply of readily decomposable organic matter and that analysis of soils for mineralizable carbon or water-soluble organic carbon provides a good index of their capacity for denitrification of nitrate.

Relationships between the denitrification capacities of soils and total, water-soluble and readily decomposable soil organic matter

Isolation and Properties of a Low Molecular Weight β2-Globulin Occurring in Human Biological Fluids

Proteinpolysaccharide Complex from Bovine Nasal Cartilage A COMPARISON OF LOW AND HIGH SHEAR EXTRACTION PROCEDURES

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The Determination of Hexosamines According to Elson and Morgan.

/pdf/on-the-estimation-of-bound-hydroxylamine-in-biological-16d0kocsbt.pdf

On the Estimation of Bound Hydroxylamine in Biological Materials.

/pdf/metal-ammine-formation-in-aqueous-solution-vi-stability-and-1ahtnpsgte.pdf

Metal Ammine Formation in Aqueous Solution. VI. Stability and Light Absorption of Copper Ethylenediamine Ions.

/pdf/the-alkoxylation-of-simple-furans-and-related-reactions-2w9ep6jtqb.pdf

The Alkoxylation of Simple Furans and Related Reactions.

/pdf/enzymatic-breakdown-of-dextran-30eyfizmig.pdf

Aarne Tuhkanen

Papers

The Determination of Hexosamines According to Elson and Morgan.

On the Estimation of Bound Hydroxylamine in Biological Materials.

Metal Ammine Formation in Aqueous Solution. VI. Stability and Light Absorption of Copper Ethylenediamine Ions.

The Alkoxylation of Simple Furans and Related Reactions.

Enzymatic Breakdown of Dextran