Commercial formulations of mixtures of pyrethrins, piperonyl butoxide, and n-octyl bicycloheptene dicarboximide were quantitatively measured by gas chromatography. The three active ingredients of the formulations were measured simultaneously using gas chromatographic columns containing the support Chromosorb W coated with either 3% or 5 o/o SE-30 silicone. The individual pesticide components present in the formulations, ranging in amounts of 0.05 to 50.00/O of the mixtures, could be measured within a reasonable degree of accuracy.
INTROI)UCTION
Pesticide chemists generally agree that the AOAC method1 for the analysis of pyrethrin formulations is tedious, time-consuming, and lacks precision and accuracy ; the latter is evident in the collaborative report by KELSEY~. The British Joint Committee of the Pharmaceutical Society and the Society for Analytical Chemistry on Methods of Assay for Crude Drugs made a comparative detailed study of the method with the PBK (Pyrethrum Board of Kenya) procedure3 and concluded that the AOAC procedure was "inherently unsatisfactory", that it also measured "false materials", but they recommended its use as an interim measure.
The AOAC procedure measures the hydrolysis products of the pyrethrums, considered to be. chrysanthemum monocarboxylic acids which are derived from pyrethrin I and cinerin I components of the pyrethrum mixture and are reported as pyrethrin I (ref. 4) ; the measured dicarboxylic acids are derived from the pyrethrin II and cinerin II components and are reported as pyrethrin II. Recent reports5 indicate that jasmolin I would also be included in the pyrethrin I fraction and jasmolin l Publishccl with the approval of the Director of the Hawnii Agricultural Experiment Station, University of Hawaii as Journal Series No. 1181. .