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Capillary electrophoresis (CE), also designated by the acronym HPCE for "High Per- formance Capillary Electrophoresis" is a rapidly growing analytical separation method. It unites the separation technique of classical electrophoresis on plates with the instrumental methods of chromatography with respect to direct detection of the solutes separated in the capillary and their ready identification and quantification. The initial problems of inadequate reproducibility in quantitative analysis, due to the necessity of handling extremely small volumes, have largely been solved in the sec- ond generation commercial instruments. Hence, a rapid and reliable separation sys- tem is available for ionic compounds from the smallest cation (the lithium ion) up to poly anions with molecular weights ranging in the millions (such as DNA molecules). The methods of gel electrophoresis and isoelectric focusing can be readily extended to separation techniques carried out in a capillary. For nonionic compounds an addi- tional separation method is available in the form of micellar electrokinetic chroma- tography (MEKC). This involves a true chromatographic separation process because the distribution of the analytes between the buffer and the micelles is superimposed on the electrophoretic migration, which contributes substantially to the selectivity.
Modern liquid column chromatography (LC) has developed rapidly since 1969 to become a standard method of separation. If the statisticians are to be believed, the recent growth of LC has been the most specta cular development in analytical chemistry and has not yet abated be cause its vast potential for application remains to be fully exploit ed. Significant factors contributing to this continued rise are the simplicity and low cost of the required basic equipment and the rela tive ease of acquiring and interpreting the data. Unfortunately, in LC, as so often in the field of analytical chemistry, the available commercial instruments are frequently far more complicated - and consequently far more expensive - than is nec essary for routine application. Therein also lies the risk of propa gating a "black box" philosophy that would be particularly detrimen tal to chromatography. Moreover, it appears to have been forgotten, as was done previously with gas chromatography, that inadequate sep aration by a column can be remedied only with great difficulty, if at all, by electronic means. Also, whether the capillary columns recent ly advocated with great enthusiasm for LC will fulfill the expecta tions of their proponents is highly questionable unless someone comes up with some new and revolutionary ideas."
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