Development of a simple multi-residue determination method of 80 veterinary drugs in Oplegnathus punctatus by liquid chromatography coupled to quadrupole Orbitrap mass spectrometry.

Abstract

A simple, rapid and sensitive multi-residue analytical method was developed and validated for 80 veterinary drugs in Oplegnathus punctatus using ultrahigh performance liquid chromatography-Orbitrap high resolution mass spectrometry (LC-HRMS). The analytes belong to 12 different families include benzimidazoles, β-lactams, lincosamides, macrolides, nitromidazoles, quinolones, sulfonamides and trimethoprim, tetracyclines, triphenylmethane dyes, amphenicols, nonsteroidal estrogens and steroid hormones. The sample preparation was optimized base on QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure. A very simple and sufficient preparation procedure without salting-out and complex clean-up process was studied. It had been proved that water in the extract was helpful for extracting hydrophilic compounds and precipitating the lipids during the subsequent cleaning process. In addition, an appropriate percent of methanol was necessary to some analytes. Finally, a mixture of acetonitrile, methanol and water (3:1:1, v/v/v) which include 1% acetic acid and 10mM ethylenediaminetetraacetic acid disodium salt 2-hydrate was selected as the extraction solvent, and the clean-up step consisted of a low temperature procedure and two times of high-speed centrifugation to deproteinize and remove lipids. The detection and quantification of all compounds were performed by ultrahigh performance liquid chromatography coupled with electrospray ionization quadrupole Orbitrap high resolution mass spectrometry in positive and negative ion mode. This methodology was validated according to the Commission Decision 2002/657/EC and SANTE/11945/2015. The recoveries ranged from 60.74%-109.85% with relative standard deviations (RSDs)<20%. The limits of quantification (LOQs) were 0.25-25ug/kg, for the analytes which the MRL or MRPL had been established in fish tissue, the LOQs were all lower than their own legal tolerances. The values of decision limit (CCα) and detection capability (CCβ) were in the range of 1.91-1001.13ug/kg and 3.52-1002.26ug/kg, respectively. This validated method has been successfully applied on the determination of veterinary drugs in real commercial oplegnathus punctatus samples.