关键词: 超高效液相色谱-串联质谱, 调制乳, 固相萃取, 磺胺类药物

Abstract:

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the residue determination of sulfadiazine, sulfamerazine and sulfamethazine in modified milk was established. The modified milk samples were extracted and their protein precipitated with water (containing 1%(v/v) acetic acid) and methanol. Then they were purified with an HLB solid phase extraction cartridge. The separation was performed on an ACQUITY UPLC HSS T3 column (100 mm×2.1 mm, 1.8 μm) with a gradient system of water (containing 0.1%(v/v) formic acid) and acetonitrile as mobile phases at a flow rate of 0.3 mL/min, and detected by the MS in ESI+ mode. Standard curves were drawn by using matrix standard addition method, and the external standard method was used for quantitative analysis. The limits of quantification were 1 μg/kg. The calibration curves for the three sulfa drugs were linear in the mass concentration range of 1-100 μg/L with R²≥0.998. The recoveries at the levels of 1, 2, 10 μg/kg fortified samples ranged from 76.5% to 101.9% with the relative standard deviations of 1.2%-12.4%. The method is simple, rapid, accurate, and its performance can meet the requirements of the domestic and international legislations. It is suitable for the detection of sulfonamide residues in modified milk.

Key words: modified milk, solid phase extraction (SPE), sulfonamides, ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)