Carbohydrates thin-layer chromatography

Wing, R.E. and BeMiller, J.N., Preparative thin layer chromatography, in Methods in Carbohydrate Chemistry, Whistler, R.L. and BeMiller, J.N., Eds., Academic Press, New York, 1972, pp. 60-64. 

Smith and coworkers152 published a relatively complete paper on the thin-layer chromatography, on silica gel, of carbohydrates of low molecular weight. Bancher and coworkers153 reported the thin-layer chromatography of degradation products of carbohydrates, including aldonic acids and aldonolactones. 

Aromatic amines that have been used include o-toluidine, p-aminosali-cylic acid, p-aminobenzoic acid, diphenylamine and p-aminophenol. Their ability to react preferentially with a particular carbohydrate or class of carbohydrate is often useful, e.g. p-aminophenol, which shows some specificity for ketoses compared with aldoses and is useful for measuring fructose. These reagents have proved particularly useful for the visualization and identification of carbohydrates after separation of mixtures by paper or thin-layer chromatography, when colour variations and the presence or absence of a reaction aid the interpretation of the chromatogram. 

Table 9.3 Some monophasic solvents for thin-layer chromatography of carbohydrates...

M. Mecozzi and Zs. Papai, Application of curve fitting thin-layer chromatography-flame ionization detection analysis of the carbohydrate fraction in marine mucilage and marine snow samples from Italian seas. J. Chromatogr. Sci. 42 (2004) 268-274. 

It has been demonstrated that ILMs are suitable for qualitative and quantitative analyses of low-molecular weight compounds of biological interest, for example, carbohydrates, vitamins and amino acids [38], and glycolipids [40]. ILMs were further used for fhe direct analysis of alkaloids, anesthetics and antibiotics, separated by thin-layer chromatography (TLC) [46]. For this purpose, the ILM was spotted onto the fractions on the TLC-plates and the complete plate was measured in MALDI MS without the need for additional pretreatment of the TLC-samples. The mass deviation inherently caused by the inhomogeneous surface of fhe TLC-plafe was balanced by using the... 

A procedure, devised by Kuhn and coworkers, that employs methyl iodide and silver oxide in N,N-dimethylformamide is frequently used for the permethylation of carbohydrates. When applied to sulfonic esters of carbohydrates, two side-reactions are found if appropriate structures are present, namely 3,6-anhydro ring formation, and conversion of a primary methylsulfonyloxy group into a methoxyl group. These side reactions were minimized by conducting the meth-ylation at 0° instead of at room temperature, and by processing the reaction mixture as soon as the reaction was complete, as shown by thin-layer chromatography. With methyl 2,3-di-0-p-tolylsulfonyl-6-O-trityl-a-D-glucopyranoside, methylation was effected in 86% yield with methyl iodide and silver oxide in hot acetone, without occurrence of desulfonylation. 

It is impossible to conclude this discussion on FAB without mentioning the possibility of recording the spectrum of a substance directly from a thin-layer chromatography (TLC) plate (84AC109 84UP1), as this will have direct applications (on paper chromatography) in carbohydrate analysis. 

Robyt JF (2000) Thin-layer Chromatography of Carbohydrates. In Wilson ID, Cooke M, Poole CF (eds) Encyclopedia of Separation Science, vol. 5. Academic Press, San Francisco, pp 2235-2244... 

There are many publications and comprehensive handbooks on the thin-layer chromatography (TLC) of carbohydrates (e.g., Refs. 1 and 2). The reason is their great importance in life science and the great diversity of cases monosaccharide, disaccharide, trisaccharide, oligosaccharide, polysaccharide, aldose, ke-tose, triose, tetrose, pentose, hexose, as well as reducing and nonreducing sugars. In addition, when extracted from natural products or produced by fermentation, carbohydrates are accompanied by many impurities. That is why separation methods are used predominantly for their analysis. 

Silica gel is the most extensively used adsorbent in thin layer chromatography because it leads to excellent, uncomplicated separations. It can be successfully employed for both qualitative and quantitative thin layer chromatographic analyses. It is usually used as a stationary phase in separations and analysis of alkaloids, various organic acids (especially amino acids and their derivatives), steroids, lipids, vitamins, plant pigments, pesticides, drugs, carbohydrates, phenolic substances, etc. 

Young DS, Jackson AJ. Thin-layer chromatography of urinary carbohydrates. A comparative evaluation of procedures. Clin Chem 1970 16 954-9. 

Ghebregzabher, M., Rufini, S., Monaldi, B. and Lato, M. Thin-layer chromatography of carbohydrates. J Chromatogr, 127, 133, 1976. 

Thin-layer Chromatography. — A t.l.c. method for the analysis of eleven carbohydrates commonly found in foodstuffs has been described using silica gel plates, which are eluted three times with acetonitrile-water (85 15). The spots were visualized using a diphenylamine dip and estimated spectrophoto-metrically. ... 

Following acid hydrolysis the monosaccharide composition of the carbohydrate fraction was determined by HPLC or by thin-layer chromatography. 

See also Amino Acids. Carbohydrates Overview. Food and Nutritionai Anaiysis Sample Preparation Packaging Materials. Liquid Chromatography Overview. Thin-Layer Chromatography Overview. 

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