Molecularly imprinted solid-phase extraction method for the gas chromatographic analysis of organochlorine fungicides in ginseng.

A highly selective molecularly imprinted solid-phase extraction coupled with gas chromatography method was developed for the simultaneous isolation and determination of four organochlorine fungicides (pentachloronitrobenzene, pentachloroaniline, methylpentachlorophenyl sulfide, and hexachlorobenzene) in ginseng samples. A novel molecularly imprinted polymer with pentachloronitrobenzene as template was synthesized by precipitation polymerization employing butanone/n-heptane (6.5:3.5, v/v) solution as porogen. The limit of detection of the method was 0.001 mg/kg, and the limit of quantification was 0.002 mg/kg. The different spiked levels of ginseng samples were 0.05, 0.5, 2.0 for pentachloronitrobenzene and pentachloroaniline, and 0.01, 0.1, 1.0 for methylpentachlorophenyl sulfide and hexachlorobenzene. The average recoveries of four organochlorine fungicides were 87.6-92.3% of pentachloronitrobenzene, 79.3-95.2% of pentachloroaniline, 80.3-90.4% of methylpentachlorophenyl sulfide, and 83.5-91.7% of hexachlorobenzene, respectively. This new method could be applied to direct determination of four organochlorine fungicides in ginseng samples.