Indirect chiral separations capillary electrophoresis

Wan H, Andersson PE, Engstrom P, Blomberg LG (1995) Direct and indirect chiral separation of amino acids by capillary electrophoresis. J Chromatogr A 704 179-193 Varesio E, Gauvrit JY, Longeray R, Lanteri P, Veuthey J-L (1997).Central composite design in the chiral analysis of amphetamines by capillary electrophoresis. Electrophoresis 18 931-936... 

Chiral separation of drng molecules and of their precursors, in the case of synthesis of enantiomerically pure drugs, is one of the important application areas of HPLC in pharmaceutical analysis. Besides HPLC, capillary electrophoresis (CE) is another technique of choice for chiral separations. Chapter 18 provides an overview of the different modes (e.g., direct and indirect ones) of obtaining a chiral separation in HPLC and CE. The direct approaches, i.e., those where the compound of interest is not derivatized prior to separation, are discussed in more detail since they are cnrrently the most frequently used techniques. These approaches require the use of the so-called chiral selectors to enable enantioselective recognition and enantiomeric separation. Many different molecnles have been nsed as chiral selectors, both in HPLC and CE. They can be classified into three different groups, based on their... 

Capillary Electrophoresis (CE) and Micellar Electrokinetic Chromatography (MEKC). - Di(2-ethylhexyl) thiophosphoric acid (DEHTPA) has been earlier characterised by potentiometric titration, and quantified by capillary zone electrophoresis with carbonate buffer, operating at —20 kV, and using UV detection at 210 nm. ° Also, a comparison has been made of capillary electrophoresis (CE) and liquid chromatography (LC) for the enantiomeric separation of a-phosphonosulfonic acids, where CE used 3-cyclodextrin as chiral selector in a borate electrolyte. Alkylphosphonic acids, at trace levels in water, have been determined by CE coupled online with flame photomeric detection, and alkylphosphonic acid esters have been separated and determined by CE using indirect UV detection. 

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