Multiresidue Pesticide Analysis of Ginseng Powders Using Acetonitrile- or Acetone-Based Extraction, Solid-Phase Extraction Cleanup, and Gas Chromatography−Mass Spectrometry/Selective Ion Monitoring (GC-MS/SIM) or −Tandem Mass Spectrometry (GC-MS/MS)

A multiresidue method for the analysis of 168 pesticides in dried powdered ginseng has been developed using acetonitrile or acetone mixture (acetone/cyclohexane/ethyl acetate, 2:1:1 v/v/v) extraction, solid-phase extraction (SPE) cleanup with octyl-bonded silica (C8), graphitized carbon black/primary−secondary amine (GCB/PSA) sorbents and toluene, and capillary gas chromatography−mass spectrometry/selective ion monitoring (GC-MS/SIM) or −tandem mass spectrometry (GC-MS/MS). The geometric mean limits of quantitation (LOQs) were 53 and 6 μg/kg for the acetonitrile extraction and 48 and 7 μg/kg for the acetone-based extraction for GC-MS/SIM and GC-MS/MS, respectively. Mean percent recoveries and standard deviations from the ginseng fortified at 25, 100, and 500 μg/kg using GC-MS/SIM were 87 ± 10, 88 ± 8, and 86 ± 10% from acetonitrile extracts and 88 ± 13, 88 ± 12, and 88 ± 14% from acetone mixture extracts, respectively. The mean percent recoveries from the ginseng at the 25, 100, and 500 μg/kg levels using GC-MS/MS were 83 ± 19, 90 ± 13, and 89 ± 11% from acetonitrile extracts and 98 ± 20, 91 ± 13, and 88 ± 14% from acetone extracts, respectively. Twelve dried ginseng products were found to contain one or more of the following pesticides and their metabolites: BHCs (benzene hexachlorides, α-, β-, γ-, and δ-), chlorothalonil, chlorpyrifos, DDT (dichlorodiphenyl trichloroethane), dacthal, diazinon, iprodione, quintozene, and procymidone ranging from <1 to >4000 μg/kg. No significant differences were found between the two extraction solvents, and GC-MS/MS was found to be more specific and sensitive than GC-MS/SIM. The procedures described were shown to be effective in screening, identifying, confirming, and quantitating pesticides in commercial ginseng products.