Dissipation and residues determination of propamocarb in ginseng and soil by high-performance liquid chromatography coupled with tandem mass spectrometry.

Two-year field trials were performed at two experimental sites to investigate dissipation and terminal residues of propamocarb in ginseng root, stem, leaf, and soil by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Mean recoveries ranged from 80.5 to 95.6% with relative standard deviations (RSDs) of 5.5-9.1% at fortified levels of 0.01, 0.02, 0.05 and 0.20 mg kg(-1). The half-lives of propamocarb were 5.00-11.36 days in root, 5.07-11.46 days in stem, 6.83-11.31 days in leaf and 6.44-8.43 days in soil. The terminal residues of propamocarb were below the maximum residue limits (MRLs) of EU (0.20 mg kg(-1)) and South Korea (0.50 mg kg(-1) in fresh ginseng and 1.0 mg kg(-1) in dried ginseng) over 28 days after last spraying at recommended dosage. The results provide a quantitative basis for establishing the MRL and give a suggestion of safe and reasonable use of propamocarb in ginseng.