The Rapid Analysis of Antibiotics in Animal Meat and Egg Using a Novel SEP Method and UPLC-MS/MS

A simple and sensitive method for the determination of 39 antibiotics, including sulfonamides and quinolones, in pork, chicken, fish tissues and eggs, has been developed. The sample preparation included ultrasound-assisted extraction (UAE) with 0.1% formic acid in 90:10 acetonitrile/water (v:v) and a final clean-up with Oasis PRiME HLB, a new reversed phase SPE without traditional pre-equilibration and washing steps before eluting SPE. Analysis was performed by ultra-performance liquid chromatography coupled to tandem quadrupole mass spectrometry (UPLC-MS/MS). The positive ionization in multiple reaction monitoring mode (MRM) and product ion confirmation scan (PICs) were used in the method. The PICs provides additional confirmation for compound identification through acquisition of MS/MS spectra in the same injection and a means of verifying that the signal from the MRM peak is from the compound of interest. In particular, single test is simultaneously able to gain both quantitative MRM and qualitative full-scan MS/MS data without the need for long analysis times or repeat injection. All solvent and matrix-matched calibration curves showed excellent correlation coefficient > 0.990, with the dynamic range 0.2-100 ng mL(-1). For over 90% of the analytes, the recoveries were between 60 and 120% in all matrices studied at three spiked levels of low, medium, and high concentrations, with the intra-day precision values in the range of 2.7-20.0% and the inter-day precision values in the range of 6.2-21.3%. The limits of detection (LODs) and limits of quantification (LOQs) of all drugs were 0.05-2.6 and 0.12-5.6 mu g kg(-1), respectively. A weak matrix effect was observed for most of the compounds in four complex samples. The proposed method was proven very simple, fast, sensitive, and selective and has been successfully applied in real samples from local markets and farms.