Abstract
The separation of enantiomers of synthetic pyrethroids by subcritical and supercritical fluid chromatography was investigated using the Pirkle-type Chiral stationary phases developed for high-performance liquid chromatography. The enantioselectivities of these stationary phases were found to be sufficient in tests with reference chemicals. Using these stationary phases, enantiomers of compounds with one or two chiral centers in acid and alcohol moieties were resolved; attempts were made to improve their resolution. Significant improvement resulted with the use of lower temperature, and thermodynamic considerations suggested the effectiveness of subcritical fluid chromatography for chiral separation of pyrethroids. The elution order of enantiomers was the same as in high-performance liquid chromatography in the two cases studied. This technique is very promising, as it requires a shorter analysis time.
