液相色谱法测定鱼肉中土霉素残留前处理方法的改进

Improvement of Sample Pretreatment in the Determination of Oxytetracyline Residue in Fish Muscle by HPLC

对液相色谱法测定鱼肉中土霉素残留的前处理方法中样品提取液浓度、提取次数、不同SPE小柱、SPE小柱洗脱液及洗脱体积进行了研究改进。结果表明,用1%的高氯酸分15、10、10 mL三次提取样品,离心后经HLB小柱净化,用20 mL 5%三乙胺甲醇溶液洗脱样品,回收率高。向样品中分别添加0.05、0.1、0.15 mg/kg三个浓度水平的土霉素时,回收率为82%～86%,RSD为6%～7%,最低检测限可达0.017 mg/kg。

The effects of sample pretreatment on oxytetrecycline residue measurement in fish muscle by HPLC was studied.Such factors as concentration of extraction solvent,extraction time,SPE column,eluate and eluate volume for SPE column were compared.The results show that higher recovery is achieved when drugs in samples are extracted with 1% perchloric acid solution of 15 mL,10 mL,10 mL and cleaned up with a HLB column eluted with 20 mL methanol containing 5% triethylamine.When spiked with 0.05,0.1,0.15 mg/kg of oxytetracyline,the average recovery is in the range of 82%～86% and the relative standard deviation（RSD） is 6%～7%.The detection limit is 0.017 mg/kg.