ENANTIOMERIC SEPARATIONS OF HALOGEN-SUBSTITUTED 2-ARYLOXYPROPIONIC ACIDS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY ON A TERGURIDE-BASED CHIRAL STATIONARY-PHASE

A number of racemic halogen-substituted 2-aryloxypropionic acids, most of which have not yet been resolved, were examined by HPLC on an ergo t alkaloid-based chiral stationary phase (CSP). Baseline enantiomeric separations were obtained with a selectivity factor (alpha) within the range 1.06-1.7, thus showing the suitability of this CSP for resolvin g these compounds in optical purity control of formulations, in stereo chemical studies as well as in transformation processes in soil and ve getable tissues. Furthermore, a semipreparative-scale separation of 2- (2,4,5-trichlorophenoxy)propionic acid (Fenoprop) enantiomers was carr ied out on a 250X7.8 mm I.D, column, yielding approximately 1.0 mg of each enantiomer in a single chromatographic run, with a recovery of 88 % and optical purity greater than 99%.