Elaboration of analytic method and preliminary results of initial investigation on chemical residues of chloro-organo-pesticides in Sanchi (Panax pseudoginseng Wall)

ABSTRACT

A solid phase extraction (SPE) and GC-ECD for multi-residues determination of 14 organo-chlorinated pesticides (OCPs) in radix Pseudo-ginseng were introduced. Using n-hexane as extracting solvent and silica gel for clean up of sample extract, with GC-ECD analysis, good separation of 14 OCPs and carbophenothion(IS) was achieved on capillary column coated with poly(5% diphenyl) siloxane. Experiments showed that n-hexane is adequate as extracting solvent(percentage of recovery70% for 13 in total 14 analyses), the LOD was about 0.35 to 1.6 ppb for blank sample spiked with standards. The method has been carried out on 7 samples collected from market for preliminary investigation of its actual OCPs residues. For 14 OCPs being analysed, results showed that all samples to be examined are complied with requirements of MRL in USP 24 or in Eur. P97.We may conclude that those samples were cultivated in less contaminated soils or none of 14 OCPs was still in illegal use