Simultaneous Determination of 26 Pesticide Residues in Traditional Chinese Medicinal Leeches by Modified QuEChERS Coupled with HPLC–MS/MS

Abstract

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.

Design, Synthesis, and Herbicidal Activity of Substituted 3-(Pyridin-2-yl)Phenylamino Derivatives

“…After vortexing for 5 min, the mixture was sonicated for an additional 30 min. The resulting supernatant was collected, passed through a 0.22 μm organic membrane filter, and prepared for LC-MS analysis …”

“…The resulting supernatant was collected, passed through a 0.22 μm organic membrane filter, and prepared for LC-MS analysis. 37 ■ RESULTS AND DISCUSSION Synthesis. The synthetic routes for compounds 6a−6h, 7a−7o, and 8a−8j are depicted in Scheme 1.…”

A core–shell structured AuNPs@ZnCo-MOF SERS substrate for sensitive and selective detection of thiram

“…5–8 For these reasons, the establishment of rapid, reliable, and highly sensitive detection methods to accurately detect low concentrations of thiram has been a hot research topic, which is of great significance in terms of food safety monitoring. Traditional detection techniques include fluorescence, 9 chromatography (HPLC, 10 GC-MS, 11 and LC-MS 12 ), electrochemistry 13 and enzyme inhibition methods. 14 These conventional methods have the advantages of wide linearity, high accuracy, and sensitivity.…”

Sensitive determination of thiram in apple samples using a ZIF-67 modified Si/Au@Ag composite as a SERS substrate

“…3 Therefore, it is vital to develop simple and effective methods for monitoring the content of thiram in food. Conventional methods, such as high-performance liquid chromatography (HPLC), 4 gas chromatography-mass spectrometry (GC-MS), 5 electrochemical analysis, 6 and colorimetric sensor detection, 7 frequently require time-consuming sample processing, large amounts of reagents, and well-trained technicians.…”