Boison J O, Keng L J, MacNeil J D
Agriculture Canada, Food Production and Inspection Branch, Saskatoon, SK.
J AOAC Int. 1994 May-Jun;77(3):565-70.
A liquid chromatographic (LC) method that was previously developed for penicillin G residues in animal tissues has been adapted to milk and milk products. After protein precipitation with sodium tungstate, samples are applied to a C18 solid-phase extraction cartridge, from which penicillin is eluted, derivatized with 1,2,4-triazole-mercuric chloride solution, and analyzed by isocratic liquid chromatography (LC) on a C18 column with UV detection at 325 nm. Quantitation is done with reference to penicillin V as an internal standard. Penicillin G recoveries were determined to be > 70% on standards fortified at 3-60 ppb. Accuracy approached 100% using the penicillin V internal standard. The detection limit for penicillin G residues was 3 ppb in fluid milk. Samples may be confirmed by thermospray/LC at concentrations approaching the detection limit of the UV method.
一种先前开发用于检测动物组织中青霉素G残留量的液相色谱（LC）方法已适用于牛奶和奶制品。用钨酸钠进行蛋白质沉淀后，将样品加至C18固相萃取柱，从中洗脱青霉素，用1,2,4 - 三唑 - 氯化汞溶液进行衍生化，然后在C18柱上通过等度液相色谱（LC）在325nm处进行紫外检测分析。以青霉素V作为内标进行定量。在添加浓度为3 - 60 ppb的标准品时，青霉素G的回收率测定结果大于70%。使用青霉素V内标时，准确度接近100%。液态奶中青霉素G残留的检测限为3 ppb。在浓度接近紫外法检测限时，可用热喷雾/液相色谱法对样品进行确证。
