A Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) pretreatment technique combined with HPLC–MS/MS was established to detect 26 pesticides in traditional Chinese medicinal leeches. The sample was extracted by acetonitrile solution with sodium acetate-0.1% (v/v) acetic acid as a buffer system, then cleaned up by a mixture of 750 mg of MgSO4, 150 mg of C18, and 150 mg of PSA, separated by an ACQUITY BEH C18 column, and determined in the dynamic multiple reaction mode. Under the optimized conditions, the peak areas of the 26 pesticides in leeches showed good linearity (r > 0.99) between their mass concentrations from 1 to 100 μg/L. At the spike levels of 10, 20, and 100 μg/kg, the recoveries of 26 pesticides in leeches were 72.9–101.6% with an RSD of 1.1–12.8%, an LOQ of 10 μg/kg, and an LOD of 0.1–5.4 μg/kg. This method is easy, rapid, sensitive, and practical and meets the requirements of pesticide residue detection standards.

The purposes of this study were to explore the systemic properties of vanisulfane in tobacco plant and to provide a reference for the rational use of vanisulfane in the field. After the tobacco plants were treated by hydroponics and foliar spraying, the contents of vanisulfane in root and stem leaf were detected by high-performance liquid chromatography tandem high-resolution mass spectrometry (UPLC-HRMS), and the position of vanisulfane in root and stem leaf was real-time observed through fluorescence two-photon confocal microscope. UPLC-HRMS results showed that the contents of vanisulfane in root and stem leaf gradually increased with the extension of processing time, and after 12 h treatment, the contents of vanisulfane in root and stem leaf reached the maximum levels of 31.95 and 0.215 mg/kg, respectively. In addition, fluorescence two-photon confocal microscope results showed that vanisulfane could observe in the root and stem leaf. These results showed that vanisulfane had excellent upward and downward of systemic in tobacco plants, which is helpful to guide a reference for the rational use of vanisulfane in the field.