Determination of procymidone residues in ginseng by GC–ECD and GC–MS equipped with a solvent-free solid injector

Abstract

A rapid method for determination of the insecticide procymidone in ginseng was studied by gas chromatographic analysis equipped with a solvent-free solid injector, Keele injector. Ginseng samples were freeze-dried, weighed carefully in milligram quantities and introduced into a glass tube in a Keele injector at a gas chromatograph injection port. The glass tube was then crushed to allow the sample to directly carry onto a capillary column in a normal manner. The recoveries of procymidone by the Keele injector method were close to those by a traditional method using a syringe, giving the recovery values ranging from 86% to 92% at the tested concentrations of 0.1 and 1.0 mg/kg. The Keele injector method was examined to detect procymidone in ginsengs obtained from agricultural markets. When 27 ginseng samples were analyzed by GC–MS and GC–ECD equipped with the Keele injector method, 14 samples of them contained procymidone in concentrations ranging from 0.2 to 0.8 mg/kg, which was the same results by the traditional method. Using the Keele injector method could skip sample preparation steps required generally in the traditional method. The data suggest that the Keele injector can be used as a sample introduction device for GC–ECD or GC–MS analysis of procymidone residues in ginsengs.