Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Milk and Milk Products Inspection Center of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
Key Laboratory of Quality & Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Laboratory of Quality and Safety Risk Assessment for Dairy Products of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China; Milk and Milk Products Inspection Center of Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
J Dairy Sci. 2019 Nov;102(11):9605-9610. doi: 10.3168/jds.2018-16187. Epub 2019 Aug 22.
We developed a sensitive and selective isotope dilution ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of sulbactam residue in raw bovine milk. Sulbactam and internal standard, sulbactam-d, were extracted from raw bovine milk via liquid-liquid extraction and enriched with strong anion exchange solid-phase extraction cartridges and finally analyzed by using UPLC-MS/MS with multiple reaction monitoring mode. The method was validated according to European regulations. The calibration curve showed good linearity, with a correlation coefficient of 0.9998. Decision limit and detection capability of sulbactam were determined by matrix calibration curve and were 0.0445 and 0.0517 μg/L, respectively. The recoveries of sulbactam in fortified raw bovine milk ranged from 72.1 to 91.5%, with the intra- and interday relative standard deviations ranging from 3.0 to 18.9%. Furthermore, the developed method was applied to analyzing real raw bovine milk samples collected from dairy farms in Beijing, China. Sulbactam was not determined in all samples. The proposed method could ultimately serve as a methodological foundation for the determination of sulbactam in different types of raw milk and dairy products.
我们开发了一种灵敏、选择性的同位素稀释超高效液相色谱-串联质谱（UPLC-MS/MS）方法，用于测定生牛乳中的舒巴坦残留量。舒巴坦和内标舒巴坦-d 通过液液萃取从生牛乳中提取，然后用强阴离子交换固相萃取小柱进行富集，最后采用多反应监测模式的 UPLC-MS/MS 进行分析。该方法按照欧洲法规进行了验证。校准曲线呈良好的线性，相关系数为 0.9998。通过基质校准曲线确定了舒巴坦的决策限和检测限，分别为 0.0445 和 0.0517 μg/L。舒巴坦在添加生牛乳中的回收率为 72.1%至 91.5%，日内和日间相对标准偏差为 3.0%至 18.9%。此外，该方法还应用于分析来自中国北京奶牛场的真实生牛乳样品，所有样品中均未检测到舒巴坦。该方法最终可作为不同类型生牛乳和乳制品中舒巴坦测定的方法学基础。
