超高压液相色谱-串联四级杆飞行时间质谱法同时筛查猪肉中54种兽药

应用超高压液相色谱串联四级杆飞行时间质谱建立了筛查猪肉中54种兽药的新方法。样品经过乙腈∶水＝5∶1（ V ∶ V）和5％三氯乙酸两次提取，旋蒸后经Waters Oasis HLB柱净化后上机测定，样品在正负离子模式下进行检测，在50～1500 Da质量范围内进行一级全扫描，以保留时间、化合物精确分子离子质量和特征碎片离子质量对药物进行定性分析。结果表明，在低中高三个添加浓度下测定了各种药物的回收率，54种兽药在4～1．5×104μg／L范围内线性关系良好，相关系数r2≥0．98。54种药物的质量数误差绝对值小于7．71×10-6，不同兽药在猪肉中回收率为10％～128％。猪肉中检出限为2～10μg／kg。该方法适用于猪肉中54种兽药的检测需要，该方法操作简单，准确，杂质干扰少。

Screening Method for 54 Drugs in Pork by Ultra Performance Liquid Chromatography- Quadrupole Time-of-Flight Mass Spectrometry

A method based on ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry （ UPLC-QTOF） has been developed for quantitative analysis of 54 kinds of drugs in pork. The conditions of sample preparation and analysis were optimized in this thesis . The drugs were fristly extracted with 25 mL acetonoitrile and 5 mL deionized water, after adding 2 g NaCl, the extract was evaporated to 5 mL under nitrogen at 40 ℃. The second extraction of residues was carried out by 20 mL 5% trichloroacetic. After adjusting the second extracting solution to pH=6.5 with 6 mol/L NaOH, all of the extarcting solutions were purified with a 500 mg Waters Oasis HLB SPE cartridge. 54 drugs were detected under both positive electrospray ionization （ ESI） and negtive electrospray ionization （ ESI ） based on retention time, accurate mass and fragment ions information. The average recoveries ranged from 10% to 128% of 54 kinds of drugs in pork at three different levels. The limits of detection were ranged from 2 μg/kg to 10 μg/kg. The results indicated that the method develop was highly sensitive and selective in screening for 54 kinds of drugs in pork.