Residue Analysis of 60 Pesticides in Red Swamp Crayfish Using QuEChERS with High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

In this study, a multi-residue analytical method using quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and dispersive solid-phase extraction (d-SPE) cleanup, followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), was investigated for rapid determination of 60 pesticide residues in whole crayfish and crayfish meat. The final method used 10 mL of acetonitrile for extraction, 3 g of NaCl for partitioning, and 50 mg of primary secondary amine for d-SPE cleanup. The method was validated at three spiking levels (10, 50, and 100 ng/g) using triphenyl phosphate as an internal standard and both gradient and isocratic HPLC elution. Under gradient conditions, satisfactory recoveries (70-120%) and relative standard deviations of ≤20% were achieved for 83 and 88% of pesticides in whole crayfish and crayfish meat, respectively. Matrix effects were estimated using both gradient and isocratic HPLC elution. To our knowledge, this is the first study involving multi-residue analysis of HPLC-amenable pesticides in crayfish and mantis shrimp. The final method was successfully applied for analysis of 11 crayfish and mantis shrimp samples from markets in China, and propamocarb (<limit of quantitation) and difenoconazole (8 ng/g) were detected in two different mantis shrimps.