QUANTITATIVE HIGH-RESOLUTION GAS-CHROMATOGRAPHIC DETERMINATION OF STEREOISOMERIC COMPOSITION OF CHIRAL VOLATILE COMPOUNDS IN THE PICOGRAM RANGE BY EC-DETECTION

A gas chromatographic method using electron capture detection for dete rmination of the stereochemical composition of chiralolatile compounds , e.g., pheromones, at the picogram level is described. Substances of interest are analyzed as pentafluorobenzoate derivatives on fused sili ca capillary columns coated with CP Sil-88. This method was developed primarily for the quantitative analyses of stereoisomerism of the pher omone precursor, diprionol, in female sawflies, Neodiprion sertifer. I t was possible to separate the stereoisomers showing (2S, 3S, 7R) and (2S, 3S, 7S) configurations. Resolution of the (2S, 3S, 7S)- and (2S, 3R, 7R)-diastereomers was high enough to allow the quantification of t hese stereoisomers. A quantitative analysis of the diprionol productio n in individual N. sertifer females yielded 7.5-9.7 ng/female.