Partition chromatography, carbohydrate analysis

Larsson and Degens [171] devised an automated system for determining carbohydrates in biological samples using partition chromatography for the separation and the orcinol colorimetric method for the final analysis. Later versions of this kind of autoanalyser, using tetrazolium blue or a Cu1 complex of bicinchoninate for the final measurement, have been reported [172]. 

Several new phases applied to maltosaccharide analysis that seem to be promising have been described in the literature, for instance, a silica-phase covered with polymeric polyamine resin, and an entirely polymeric resin containing an amide function (35). In any case, partition chromatography is restricted mainly to the utilization of polar-bonded phases, as already described. Nevertheless, there have been a certain number of applications of reversed-phase chromatography that permit relatively simple separations to be achieved. Octadecyl-bonded silica phases are the most widely used, although few applications involve carbohydrate analysis. Their interest lies rather in the analysis of derivated sugars, where the selectivity increases (36). 

The introduction of any new analytical technique seems to inspire its indiscriminate application, without use of proper precautions, to a variety of problems, many of which could be solved more quickly by other methods. It should be emphasized that gas-liquid chromatography is not a panacea for all problems in the analysis of carbohydrate derivatives. Fast, efficient resolution of any given mixture of derivatives requires judicious selection from among the methods of countercurrent partition, liquid-liquid chromatography on columns or paper, adsorption chromatography on columns or thin layers, electrophoresis, and gas-liquid chromatography. The last method is, under the appropriate conditions, a powerful addition to the list because of its high efficiency and rapid operation, and the reliability of both the qualitative and the quantitative results. 

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