DETECTION AND QUANTIFICATION OF TRACE LEVELS OF CARBARYL AND ITS METABOLITES FROM DENDROCTONUS-FRONTALIS ZIMMERMANN

A direct and sensitive high-performance liquid chromatographic (HPLC) method was developed for the detection and quantitative analysis of ca rbaryl and metabolites at the parts-per-billion level using a YMC stai nless steel reversed-phase ODS (mu Bondapak C-18) HPLC column (250 mm x 3.9 nm i.d.), equipped with a Waters Guard-Pak C-18 precolumn module . The use of this methodology combined with radioisotopic technique is demonstrated by topically treating the southern pine beetle, Dendroct onus frontalis Zimmermann, with [naphthyl-1-C-14]carbaryl and analyzin g methanolic extracts of the exoskeleton, the vials in which beetles w ere held, and the whole body homogenates at various incubation time in tervals after treatment. All extracts were passed through a Millex-HV 0.45-mu m filter unit (Millipore, Bedford, MA) prior to HPLC analysis. Advantages of this method include high sensitivity, reproducibility, short analysis time, and good recovery. This HPLC method should be use ful for toxicological and environmental studies that require the detec tion of nanogram concentrations of carbaryl and carbaryl metabolites.