Meetschen U, Petz M
Bergische Universität Wuppertal, Bundesrepublik Deutschland.
Z Lebensm Unters Forsch. 1991 Oct;193(4):337-43. doi: 10.1007/BF01191630.
A capillary gas chromatographic method is described for the determination of residues of benzylpenicillin, phenoxymethylpanicillin, methicillin, oxacillin, cloxacillin, dicloxacillin and nafcillin in bovine muscle, liver, kidney, adipose tissue and milk. The samples are extracted with acetonitrile under slightly acidic conditions, the co-extracted water is separated with the addition of sodium chloride and dichloromethane and discarded. Clean-up is performed by liquid/liquid partitioning steps and anion exchange chromatography. The penicillin residues are methylated with diazomethane. After derivatization, only the extracts from liver and kidney needed further clean-up using cartridges with a polar diol sorbent. The gas chromatographic procedure is based on split/splitless injection, programmed temperature vaporization, separation on a methyl silicone fused silica column and nitrogen-specific thermionic detection. Internal standardization is used for quantification. The limits of detection for all penicillins are well below 3 microgram/kg in milk and all tissues. Recoveries of spiked samples at 3 and 10 micrograms/kg are in the range of 65-80% for milk and 50-70% for bovine tissues.
本文描述了一种毛细管气相色谱法，用于测定牛肌肉、肝脏、肾脏、脂肪组织和牛奶中苄青霉素、苯氧甲基青霉素、甲氧西林、苯唑西林、氯唑西林、双氯西林和萘夫西林的残留量。样品在微酸性条件下用乙腈萃取，加入氯化钠和二氯甲烷分离共萃取的水并弃去。通过液/液分配步骤和阴离子交换色谱进行净化。青霉素残留用重氮甲烷甲基化。衍生化后，只有肝脏和肾脏的提取物需要使用带有极性二醇吸附剂的小柱进一步净化。气相色谱程序基于分流/不分流进样、程序升温汽化、在甲基硅氧烷熔融石英柱上分离和氮特异性热离子检测。采用内标法定量。所有青霉素在牛奶和所有组织中的检测限均远低于3微克/千克。加标样品在3和10微克/千克时，牛奶的回收率在65-80%范围内，牛组织的回收率在50-70%范围内。
