液相色谱-串联质谱法测定蔬菜和水果中的赤霉素及高效氯氰菊酯

Determination of gibberellin andβ-cypermethrin in vegetables and fruits by liquid chromatography tandem mass spectrometry

建立了液相色谱-串联质谱(LC-MS/MS)法同时测定赤霉素和高效氯氰菊酯在普通白菜、豇豆、香蕉、葡萄的农药残留检测方法。待测试样经过乙腈振摇提取,经过盐析原理进行分层,吸取澄清乙腈层,用50%甲醇1∶1(V/V)稀释,用乙腈和5 mmol/L乙酸铵溶液进行梯度洗脱分离,利用正负离子源模式(ESI、ESI)多反应监测(MRM)数据采集,离子比定性,基质匹配外标法定量。结果表明,对2种农药进行3个水平添加(0.040、0.100、0.400 mg/kg)时的平均回收率为80.0%~112.1%,相对标准偏差(RSD)<15%。LC-MS/MS法检测分别得到赤霉素和高效氯氰菊酯标准液的标准曲线,其在质量浓度0.010~0.400 mg/L范围内线性关系良好,相关系数(R)均大于0.999;方法检出限(LODs)均值为0.001 mg/kg,定量限(LQDs)均值为0.004 mg/kg,满足常规检测方法要求。该测定方法前处理操作便捷,适合大批量样品的筛查,具备良好的灵敏度、准确度和精密度,为提高蔬菜水果的质量和安全性提供了耗材低、高效、可信的定性定量检测方法。

A method for simultaneous determination of gibberellin andβ-cypermethrin residues in vegetables and fruits by liquid chro⁃matography tandem mass spectrometry was established.The samples were extracted by acetonitrile shake and separated by salting out principle,and the clarified acetonitrile layer was dissolved in 50%methanol 1∶1(V/V),and the acetonitrile was separated by acetoni⁃trile and 5 mmol/L ammonium acetate solution.The data were collected by electrospray ionization mode(ESI+,ESI-)Multi-reaction monitoring(MRM),and the external standard method was used to quantify the ionic ratio.The results showed that the average recover⁃ies of the two pesticides at three levels(0.040,0.100 and 0.400 mg/kg)ranged from 80.0%to 112.1%,and the relative standard devi⁃ation(RSD)was less than 15%.The standard curves of gibberellin andβ-cypermethrin standard solutions were obtained by LC-MS/MS.The linear relationship was good in the range of mass concentration 0.010~0.400 mg/L,and the correlation coefficient R2 was greater than 0.999.The limits of detection(LODs)were 0.001 mg/kg and the limits of quantification(LQDs)were 0.004 mg/kg,which met the requirements of conventional detection methods.The method is convenient for pre-processing and is suitable for screening large quantities of samples.It has good sensitivity,accuracy and precision.It is a low-consumable,efficient and reliable qualitative and quantitative detection method for improving the quality and safety of vegetables and fruits.