Rapid Screening of 14 Sulfonamides in Raw Milk by Ultra Performance Liquid Chromatography-Quadrupole Time-of-flight Mass Spectrometry

KeyWord:ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry£¨UHPLC-Q TOF MS£©  raw milk  sulfonamides  rapid screening

Abstract:

      A comprehensive analytical method was established for the simultaneous determination of 14 sulfonamides£¨sulfadimidine,sulfadiazine,sulfadimethoxine,sulfathiazole,sulfapyridine,sulfachloropyridazine,sulfamerazine,sulfacetamide,sulfatroxazole,sulfaphenazole,sulfabenzamide,sulfamethizole,sulfamethoxypyridazine and sulfamethoxazole£© in raw milk by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry£¨UHPLC-Q TOF MS£©.The accurate mass and two-stage mass spectrometry databases of 14 compounds were established.The analytes in milk samples were extracted with acetonitrile containing 0.1%formic acid.The extracts were cleaned up through QuEChERS method. The target compounds were separated on an Agilent ZORBAX SB C18 column by gradient elution using acetonitrile-0ª±1% formic acid solution as mobile phase,and detected by MS in Dual AJS ESI+ mode.The 14 sulfonamides could be separated in 8 min.As a result,the limits of quantitation£¨LOQ,S/N=10£©of 14 target compounds were 10 ¦Ìg/kg in milk.The average recoveries of 14 analytes spiked at three concentration levels in the range of 72.5%-117.1% with relative standard deviations of 1.3%-10.9%.The precision mass,retention time,isotopic abundance and two-stage ion mass spectra were employed for the screening and confirmation.This method could be applied in the high-throughput screening and qualitative identification of 14 sulfonamides in raw milk due to its fastness,simplicity and relatively high sensitivity.