Multiparallel microfluidic high-performance liquid chromatography for high-throughput normal-phase chiral analysis

The suitability of the Eksigent Express 800 microfluidic eight-channel HPLC instrument for multiparallel normal-phase chiral analysis in support of high-throuhput pharmaceutical process research was investigated. Analysis of test mixtures containing the two enantiomers of benzoin and the closely related (R,S)-dihydrobenzoin, was carried out in a 96-well microplate, affording rapid (< 2 h) and accurate assessment of enantiopurity. In a second example, use of the instrument to support high-throughput catalyst screening of the asymmetric hydrogenation of a prochiral unsaturated ester is presented, in which method development (gradient screening of four columns and two eluents, followed by optimization to afford a fast analytical method) and analysis of a 96-well microplate was carried out within a single working day. This represents a considerable improvement over conventional analysis techniques that usually take several days to complete. (c) 2007 Elsevier B.V. All rights reserved.