title: Development of a modified QUick, Easy, CHeap, Effective, Rugged and Safe method for the determination of multi-class antimicrobials in vegetables by liquid chromatography tandem mass spectrometry.
abstract: A modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for rapid determination of 26 veterinary antimicrobials in vegetables. Samples were extracted by single-phase extraction with acetonitrile-methanol (85:15, v/v) and citric buffer solution, followed by liquid-liquid partitioning with the addition of anhydrous magnesium sulfate and sodium chloride. A dispersive solid-phase extraction with primary secondary amine was applied for cleanup. Concentration and solvent exchange was performed prior to LC-MS/MS analysis. All matrix-matched calibration curves were linear with correlation coefficients (r) over 0.99. Recoveries for all the analytes spiked at 0.5 (1 or 1.5), 5 and 50 ng/mL were in the range of 60.0-98.0%, except for sulfaquinoxaline, sulfaclozine and doxycycline, with relative standard deviations below 25% for the low concentration level, 20% for the medium and 15% for the high. The decision limits and the detection capabilities of the analytes ranged from 0.005 to 0.5 μg/kg and from 0.02 to 1.5 μg/kg, respectively. The method was developed and validated in accordance with romaine lettuce matrix, and higher recovery rates were obtained from the other five kinds of vegetables including white radish, Chinese cabbage, cucumber, string bean and green pepper. Matrix effects of different vegetables were evaluated and signal suppression effect was observed for the majority of 26 analytes. Finally, the method was applied to the analysis of real samples collected from the agricultural areas in the vicinity of local pig farms, and the phenomenon of vegetables contaminated by antimicrobials residues is provoking.
authors.affiliation: National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
authors.forename: Fengyang
authors.initials: F
authors.lastname: Hu
authors.affiliation: National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Bian
authors.affiliation: National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
authors.forename: Yahong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
authors.forename: Yijuan
authors.initials: Y
authors.lastname: Su
authors.affiliation: National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
authors.forename: Tong
authors.initials: T
authors.lastname: Zhou
authors.affiliation: National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China.
authors.forename: Xuqin
authors.initials: X
authors.lastname: Song
authors.affiliation: National Reference Laboratory of Veterinary Drug Residues, College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong PC 510642, China. Electronic address: liminokhe@scau.edu.cn.
authors.forename: Limin
authors.initials: L
authors.lastname: He
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013058:Mass Spectrometry; D052616:Solid Phase Extraction / Q000379:methods; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014675:Vegetables / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D012997:Solvents
keywords: Antimicrobials; Liquid chromatography-tandem mass spectrometry; QuEChERS; Vegetables