论文部分内容阅读
目的建立一种高效液相色谱-串联质谱联用法测定乳制品中7种青霉素类抗生素残留的确证方法,对市售乳制品中青霉素残留情况进行调查。方法乳制品样品采用水提取后,经乙腈沉淀蛋白,正己烷液液萃取除去脂肪,用氮气吹至近干,用乙腈+水(10+90)复溶后,经0.22μm微孔滤膜过滤,用乙腈(含0.1%甲酸)-水(含0.1%甲酸)为流动相,proshell 120 EC-C18柱分离,18 min内梯度洗脱分离7种青霉素;在优化的质谱条件下,采用ESI源、正离子模式、多反应监测方式,外标法定量。结果在1.0μg/L~100μg/L浓度范围内,7种青霉素类药物在各种乳制品基质中均有良好的线性关系(r>0.9991),液体奶最低检测限为0.03μg/kg~0.15μg/kg,固体奶的最低检测限为0.15μg/kg~0.75μg/kg;方法回收率在91.0%~102.3%,相对标准差为1.02%~6.13%。测定了49份奶粉、液体牛奶、鲜奶、奶饮料等样品,有3份样品检测出青霉素G,含量在0.2μg/kg~1.6μg/kg之间。结论该方法测定7种青霉素药物的残留量简便、快速、准确,可以满足对青霉素残留的监测要求。调查结果显示,市场上奶制品中有一定的青霉素残留,应引起有关部门的重视。
Objective To establish a method for the determination of seven penicillin antibiotics residues in dairy products by high performance liquid chromatography-tandem mass spectrometry (LC-MS / MS) and investigate the residual penicillin residues in commercially available dairy products. Methods Dairy samples were extracted with water and then precipitated by acetonitrile and liquid-liquid extraction with n-hexane to remove fat. The samples were blown to near dryness with nitrogen, reconstituted with acetonitrile + water (10 + 90), filtered through 0.22 μm microporous membrane, Seven kinds of penicillin were separated by gradient elution on a proshell 120 EC-C18 column with acetonitrile (containing 0.1% formic acid) -water (containing 0.1% formic acid) as a mobile phase and gradient elution within 18 min. Under optimized conditions, Positive ion mode, multiple reaction monitoring, external standard method. Results The results showed that there was a good linear relationship (r> 0.9991) among the seven kinds of penicillins in the range of 1.0μg / L to 100μg / L, and the minimum detection limit of liquid milk was 0.03μg / kg ~ 0.15 μg / kg. The detection limit of solid milk was 0.15μg / kg ~ 0.75μg / kg. The recoveries were 91.0% ~ 102.3% with relative standard deviations of 1.02% ~ 6.13%. A total of 49 samples of milk powder, liquid milk, fresh milk and milk beverage were determined. Penicillin G was detected in 3 samples ranging from 0.2μg / kg to 1.6μg / kg. Conclusion The method of determination of 7 kinds of penicillin residues simple, rapid and accurate, to meet the monitoring requirements of penicillin residues. Survey results show that there is a certain amount of penicillin residues in dairy products on the market, which should arouse the attention of relevant departments.