关键词: β-内酰胺酶抑制剂, 舒巴坦, 多残留检测, 酶抑制法, 头孢硝噻吩

Abstract: An enzyme inhibition method was established and used to detect the multi-residue of β-lactamase inhibitors in milk. For sample preparation, the protein was precipitated by acetonitrile and the fat was removed by n-hexane. The matrix-matched external standard method was used for quantification, which eliminated the interference of the milk matrix. The detection limits of sulbactam, potassium clavulanate, tazobactam and avibactam sodium in milk samples were 42.88, 10.20, 1.68 and 3.48 μg/kg, respectively. The average recoveries were tested from 80.43% to 115.87% with coefficients of variation below 10.14%. When the residue of β-lactamase in milk did not exceed 40 U/mL, the accuracy of the test results would not be affected. Good correlation between the enzyme inhibition method and liquid chromatography?tandem mass spectrometry was obtained for spiked milk samples, with a correlation coefficient (R2) of 0.982. The established enzyme inhibition method had the characteristics of accurate, rapid, high-throughput and multi-residue detection, which was ideally suitable for on-site screening of β-lactamase inhibitor residues in large numbers of milk samples.

Key words: β-lactamase inhibitors, sulbactam, multi-residue detection, enzyme inhibition method, nitrocefin