摘要
[目的]建立采用LC—MS—MS分析牛奶中阿莫西林、氨苄西林、氯唑西林、苯唑西林和青霉素-G残留量的方法。[方法]牛奶样品中加入内标青霉素-D7,经乙腈沉淀后,离心并吸取上清液。上清液吹干后,通过固相萃取柱净化,然后进行检测。在液相色谱分离系统中,通过Atlantis C18柱,采用0.1%甲酸水溶液与乙腈不同比例混合的梯度流动相,根据以上各成分的不同质量数的碎片离子的强度,将5种抗生素分离并测定。[结果]在2—20μg/L范围内,与内标的峰面积比有良好的线性关系。相关系数(R。)为0.9943—0.9981,在5、10μg/L水平的标准加入回收率为88%-127%。阿莫西林、氨苄西林、青霉素、氯唑西林、苯唑西林的最低检测限量分别为5、2、2、4、4μg/L(以信噪比为10:1)。[结论]该方法利用液-液萃取和固相萃取相结合的方法,并加入同位素内标,有效地去除干扰因素,为该类抗生素的测定提供了可靠、实用的测定方法。
[ Objective] To develope a high performance liquid chromatography coupled mass spectrometry method based on C18 solid - phase extraction for simultaneous determination of five β - lactam antibiotics ( amoxicillin, ampicillin, oxacillin, cloxacillin and penicillin G) in bovine milk. [ Methods ] The samples were cleaned up with C18 SPE catridge, the extracts were analyzed by liquid chromatography- electrosprapy ionization tandem mass spectrometry ( LC - MS/MS ) in the positive mode using a isotope - labeled internal standard. [ Results ] The method was validated at the 5 and 10 μg/L level for these compounds in milk, and the limit of quantification was 5, 2,2,4,4 μg/L for amoxicillin, ampicillin , penicillin G, cloxacillin and oxacillin, and the detection range was from 2 to 20 μg/L. [ Conclusion] Liquid - liquid extraction and solid - phase extraction are combined to eliminate the interfering substance while the internal standard is used. Hence this method is adoptable for the determination of five kinds of antibiotics.
出处
《上海预防医学》
CAS
2008年第3期109-112,共4页
Shanghai Journal of Preventive Medicine