CHALLENGES AND FRUSTRATIONS IN THE SEPARATION AND ANALYSIS OF CHIRAL AGROCHEMICALS

The development of chiral HPLC methods and isolation techniques within Zeneca Agrochemicals (formerly ICI Agrochemicals) is reviewed. The us e of low temperature to improve chiral separations has been successful ly applied to production analysis, but although useful for some compou nds it is regrettably not a universal panacea for all poor separations . The need to isolate small quantities of individual enantiomers from new compounds for research evaluation has led us to devise a more univ ersal and cheap chiral stationary phase (CSP) for Preparative-LC. Join t academic research produced a CSP based on tartaric acid which was ma de commercially available and it was gratifying to find it was the onl y phase able to resolve a novel insecticide. However, as new CSPs emer ged almost every month, our attention turned to using a universal chir al detector for analysis, rather than via separation of individual ena ntiomers. Diode laser-based polarimeters offered the opportunity of ch eap, sensitive chiroptical detectors for HPLC and the ability to move away from chiral columns in both research and production analysis. Joi ntly sponsored research with a university has successfully explored th e versatility of chiroptical detectors in agrochemical and food analys is. Comparison of chiral SFC with chiral HPLC and an extensive evaluat ion of established and research agrochemicals on a wide range of comme rcial CSPs have led to a revised method development strategy. Current work with high load displacement chiral chromatography will be describ ed as a potential means of isolating pure enantiomers from racemates. (C) 1994 Wiley-Liss, Inc.