超高效液相色谱-串联质谱法测定梨中多抗·喹啉铜多残留

Determination of polyoxin B and oxine-copper in pear by ultra performance liquid chromatography-tandem mass spectrometry

目的建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography-tandemmass spectrometry, UPLC-MS/MS)测定梨中多抗霉素B、喹啉铜多残留的分析方法。方法喹啉铜在酸性条件下转化为8-羟基喹啉后,其与多抗霉素B经1%乙酸溶液与甲醇(95:5,V:V)提取、PSA净化后,超高效液相色谱-串联质谱仪进行检测。结果多抗霉素B和8-羟基喹啉分别在0.001~0.50 mg/L和0.0001~0.050 mg/L浓度范围内,基质标准工作液的浓度与响应值均呈良好的线性关系,相关系数r≥0.999。多抗霉素B和喹啉铜在梨中的添加水平分别为0.010~1.0mg/kg和0.005~1.0mg/kg,多抗霉素B的平均回收率在84%~99%之间,相对标准偏差最大为5.2%;喹啉铜平均回收率在78%~88%之间,相对标准偏差最大为3.4%,表明该方法的准确度和精密度均符合残留分析的要求。其中多抗霉素B和8-羟基喹啉的方法检出限(limits of detection, LOD)分别为1.0×10^-11g和1.0×10^-12g,方法定量限(limits of quantification,LOQ)分别为0.010mg/kg和0.005mg/kg。结论该方法灵敏度较高,有助于提高多抗霉素B和喹啉铜农药的残留风险监测水平。

Objective To establish a method for the determination of polyoxin B and oxine-copper in pear by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Methods 8-hydroxy quinoline converted from oxine-copper and polyoxin B were extracted with 1% acetic acid solution and methanol(95:5, V:V), purified by PSA, and then detected by ultra liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Results The correlation coefficient(r) was no less than 0.999 within the concentration range of 0.001-0.50 mg/L and 0.0001-0.050 mg/L of polyoxin B and 8-hydroxyquinoline, respectively, which indicated a satisfied linear relation between the areas and the concentrations of two target pesticides. Meanwhile, polyoxin B and oxine-copper were fortified into pear blank samples respectively to carry out the recovery tests. The addition levels of polyoxin B and oxine-copper in pear were 0.010 to 1.0 mg/kg and 0.005 to 1.0 mg/kg. The average recoveries of polyoxin B were ranged from 84% to 99%, and the maximum relative standard deviation was 5.2%. The average recoveries of oxine-copper were ranged from 78% to 88%, and the maximum relative standard deviation was 3.4%. The accuracy and precision were accorded with the request of residue analysis. The limits of detection(LOD) of polyoxin B and 8-hydroxyquinoline were 1.0×10^-11 g and 1.0×10^-12 g, respectively. Their respective limits of quantification(LOQ) were 0.010 mg/kg and 0.005 mg/kg. Conclusion The method is of higher sensitivity, which is helpful to improve the monitoring level of residual risk of polyoxin B and oxine-copper pesticides.