Simultaneous Determination of 72 Veterinary Drugs in Shrimp by Modified QuEChERS and High Performance Liquid Chromatography-Tandem Mass Spectrometry

KeyWord:QuEChERs  LC-MS/MS  multi-residues  veterinary drugs  shrimp  determination

Abstract:

      A method was developed for the simultaneous determination of 72 veterinary residues in shrimps by QuEChERS and high performance liquid chromatography-tandem mass spectrometry.The sample was extracted with 5%acetic acid-acetonitrile,and the supernatant liquid was directly purified with C18,meanwhile,acetonitrile was used for the precipitation of protein.The extract was evaporated under nitrogen stream,and redissolved with 1 mL 0.1%formic acid-acetonitrile£¨4¡Ã1£©.Prior to the injection into LC-MS/MS,the sample was filtered through a 0.22 ¦Ìm filter membrane.The HPLC separation was performed on ZORBAX SB-C18 column by gradient elution with acetonitrile and 0.1%formic acid as mobile phase.The analysis of target compounds was carried out with electrospray ionization£¨ESI£© under multi reaction monitoring£¨MRM£© mode.The external standard method was used for quantification. Under the optimal conditions,the correlation coefficients for 97.2%of the veterinaries were larger than 0.95 in the linear range of 0.1-1 840 ¦Ìg/kg,the limits of quantitation ranged from 0.02 ¦Ìg/kg to 33.58 ¦Ìg/kg.The recoveries of 72 veterinary at three spiked levels were between 61%and 119%,except that for dibutylsuccinate,cefapirin,cefquinome,ceftiofur,lincomycin ane diazinon were between 38%and 58%,and their relative standard deviations were in the range of 1.6%-20%.The established method was used for the screening and determination of real samples£¨pteris shrimp,freshwater shrimp and sea shrimp£© bought from supermarket.It was shown that no residue was detected in the sea shrimp and pteris shrimp samples,and 4.0 ¦Ìg/kg of sulfadiazine as well as 2.2 ¦Ìg/kg of sulfamethoxazole were found in freshwater shrimp sample,but the concentrations were all lower than the MRLs.