Application of planar chromatography to sample analysis in the sugar industry

Analysis of sugar mixtures by modern liquid chromatographic techniques, both column and planar, has gained in prominence. As far as planar chromatography is concerned, the introduction of high performance bonded-phase layers and instrumental development techniques has opened up new avenues in the TLC analysis of sugars, especially for samples that normally require cumbersome clean-up processes. In chromatography, gradient elution is the technique of choice when the mixture components span a wide range of polarities (or molecular structure). Planar chromatography gradient development is also possible using an automated technique (AMD), which has been recently introduced. This technique makes large spot capacities possible because of the reconcentration effect caused by the multiple development as well as the accommodation of many spots on the same chromatographic plate, because of the gradient development. Thus, complex samples, such as beet or cane molasses, can be analyzed (or at least screened) on high-performance thin layers using modern scanners which allow a great deal of information to be obtained. In the analysis of molasses, over pressure liquid chromatography (OPLC) is also interesting. This is a forced flow technique which makes both large spot capacities and short development times possible, and can be utilized for gradient elutions as well. Details of the analysis of both beet and cane molasses are reported, and a comparison between the two techniques mentioned previously is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.