The QuEChERS-UPLC-MS/MS Method For Simultaneous Determination Of Sulfonamides And Fluoroquinolone Residue In Animal-Origin Food

QuEChERS, as a new samples processing technology, is broadly applied to the detection of pesticide residues. Sulfonamides and quinolones, two kinds of inexpensive antimicrobial agents are widely used in livestock and poultry production. However, due to abuse, misapplication and without obeying withdrawl time, these antimicrobial agents or their metabolites will be residued in animal-derived food, which poses a threat to people’s health or results in direct damage. Up to date, there is not very satisfactory method for simultaneous determination of sulfonmides and fluoroquinolones residue in animal-origin food. Therefore, the aim of the study is to establish a method used to detect multiple sulfonamides and fluoroquinolones residue in animal food.First, we optimize the conditions of extraction of drug from animal-origin samples. The protocol is as follows. The samples of5g were added in DisQuE extraction pipe and treated with100mL internal standard working liquid, one ceramic proton and20ml acetonitrile, then vortexed mixing fully, oscillated the extraction for10min at10000r/min and then centrifuged5min under4℃. Last, the precisely2.5mL supernatant was dried at50℃under nitrogen flow, and the residue was dissolved with adding1ml of0.1%formic acid aqueous solution-methanol (10:90), the liquid was filtrated using0.45mm filter membrane and used for UPLC-MS/MS determination.Then, UPLC-MS/MS method was used to simultaneously determine sulfonamides and fluoroquinolone. The results showed that the LOD and the LOQ of liquid chromatography---tandem mass spectrometry (LC-MS) were3μg/kg and10μg/kg, respectively. The results of standard curve showed a good linear relationship in the range of 10-100ng/mL. The average recovery rate of milk samples range from75.3%to108.4%at fortified concentration of20,50and100μg/kg, and LOT RSD range from5.3%to14.8%, between-run RSD was in8.1%～14.8%. The average recovery rate of egg samples range from82.3%to117.2%at fortified concentration of20,50and100μg/kg, and LOT RSD range from7.8%to14.2%, between-run RSD was7.3%～14.5%. The average recovery rate of honey samples range from81.7%to117.4%at fortified concentration of20,50and100μg/kg, and LOT RSD range from7.3%to14.5%, between-run RSD was8.7%～14.2%. The average recovery rate of pork samples ranges from74.6%to115.6%at fortified concentration of20,50and100μg/kg, LOT RSD range from7.9%to14.5%and between-run RSD range from7.2%to14.2%. The results indicated that the QuEChERS-UPLC-MS/MS method is suitable to detect multiple sulfonamides and fluoroquinolones residue in animal food.