An Orthogonal Approach to Chiral Method Development Screening

Chiral chromatography method screening strategies: Past, present and future

Method screening is an integral part of chromatographic method development for the separation of racemates. Due to the highly complex retention mechanism of a chiral stationary-phase, it is often difficult, if not impossible, to device predefined method-development steps that can be successfully applied to a wide group of molecules. The standard approach is to evaluate or screen a series of stationary and mobile-phase combinations to increase the chances of detecting a suitable separation condition. Such a process is often the rate-limiting step for high-throughput analyses and purification workflows. To address the problem, several solutions and strategies have been proposed over the years for reduction of net method-screening time. Some of the strategies have been adopted in practice while others remained confined in the literature. The main objective of this review is to revisit, critically discuss and compile the solutions published over the last two decades. We expect that making the diverse set of solutions available in a single document will help assessing the adequacy of existing screening protocols in laboratories conducting chiral separation.

Screening of Pirkle-type chiral stationary phases for HPLC enantioseparations

The majority of enantiomeric separations for purity analysis and quality control continue to be performed by normal-phase liquid chromatography and supercritical fluid chromatography. In this chapter, representative chromatographic screening procedures for the enantioseparations using Pirkle-type stationary phases are presented. As Pirkle-type phases are commonly applied to the preparative chromatographic isolation of enantiomers, volatile modifiers are used in this screen in order to be subsequently compatible with the techniques used to recover analytes from preparative scale isolations. The Stage 1 screen presented here is used initially for screening chiral entities. The gradients use cyclohexane and ethanol both with and without chromatographic modifiers. The Stage 2 screen is used for more challenging to resolve compounds that do not exhibit resolution using the Stage 1 screening procedure.

Chromatography in industry

This review focuses on the chromatography research that has been carried out within industry or in close cooperation with industry and that has been reported in the scientific literature between 2006 and mid-2008. Companies in the health care sector, such as pharmaceutical and biotechnology companies, are the largest contributors. Industrial research seems to take place in an open environment in cooperation with academia, peer companies, and institutions. Industry appears ready to embrace new technologies as they emerge, but they focus strongly on making chromatography work robustly, reliably, rapidly, and automatically. "Hyphenated" systems that incorporate on-line sample-preparation techniques and mass-spectrometric detection are the rule rather than the exception. Various multidimensional separation methods are finding numerous applications. Strategies aimed at speeding up the development of new chromatographic methods remain the focus of attention. Also, there is a clear trend toward exploring chromatographic methods for parallel processing along with other strategies for high-throughput analysis.