SUPERCRITICAL FLUID CHROMATOGRAPHIC-SEPARATION OF SYNTHETIC PYRETHROIDS ON PACKED-COLUMNS AND CAPILLARY COLUMNS

The separation of synthetic pyrethroids by supercritical fluid chromatography was investigated using four packed columns and five fused silica capillary columns. The separation of 13 pyrethroids in one injection was attempted by varying both the column temperature and pressure program. With the packed columns various elution patterns were obtained. Using polar stationary phases of the capillary columns led to a successful separation of all the geometrical isomers, as well as all 13 pyrethroids in one run. The differences in the elution order among the capillary columns and the packed columns are discussed based on a consideration of the polarization and molecular interaction. The reversal of the elution order of pyrethroid geometrical isomers with the temperature is also discussed.