Turbo flow在线净化-超高效液相色谱-串联质谱法检测水果中5种咪唑类农药残留

Determination of five imidazole pesticide residues in fruits byTurbo flow online purification-ultra performance liquid chromatography-tandem mass spectrometry

建立了 Turbo flow（TF）在线净化-超高效液相色谱-串联质谱同时检测水果中吡咪唑、咪唑烟酸、咪鲜胺、咪唑嗪和咪唑菌酮等5种咪唑类农药的方法。以饱和氯化钠溶液溶解样品，乙腈提取，蒸干，乙腈-水（1∶1，v / v）溶液定容后进入 Turbo flow-超高效液相色谱-串联质谱系统分析，外标法定量。对影响 TF 净化的条件如 TF 色谱柱、流动相、洗脱溶液、洗脱速率等进行了优化。在优化的实验条件下，以 Turbo flow C18（50 mm×1.0 mm）为净化柱，Hypersil GOLD aQ（100 mm×2.1 mm）为分析柱，乙腈和5 mmol / L 甲酸铵溶液（含0.1％（ v / v）甲酸）为流动相进行梯度洗脱，在电喷雾正离子选择反应监测模式下进行检测。结果表明，各目标化合物在0.0075~0.75 mg / L范围内线性关系良好（相关系数均大于0.99），定量限为0.005 mg / kg。对实际样品分别加标0.005、0.01、0.05和0.5 mg / kg，回收率为71.2％~122.4％，相对标准偏差（RSD）为0.5％~8.9％。该方法简便、快速，结果准确可靠，适用于水果中5种咪唑类农药残留的检测。

A Turbo flow-ultra performance liquid chromatography-tandem mass spectrometry （TF-UPLC-MS / MS）method was developed for the determination of five imidazole pesticides （imazapyr,triazoxide,rabenzazole,prochloraz and fenamidone）in fruits. The fruit samples were dissolved in saturated sodium chloride solution and extracted by acetonitrile. After the acetonitrile layer was evaporated and redissolved with acetonitrile-water（1 ∶1,v / v）,the fruit samples were analyzed by TF-UPLC-MS / MS. The main factors influencing the purification effi-ciency including the TF column,mobile phase,elution solution and elution rate were opti-mized. Under the optimized experimental conditions,the analytes were purified by Turbo flow C18 column（50 mm×1. 0 mm）and separated on a Hypersil GOLD aQ column（100 mm × 2. 1 mm）using the mobile phases of acetonitrile and 5 mmol / L ammonium acetate（ containing 0. 1% （v / v）formic acid）aqueous solution with gradient elution. The compounds were detected by selective reaction monitoring（SRM）via positive electrospray ionization（ ESI ＋）. The linear range of the method ranged from 0. 007 5 to 0. 75 mg / L for all the five imidazole pesticides, with the correlation coefficients（r 2 ）greater than 0. 99. The limits of quantification were 0. 005 mg / kg for all the five imidazole pesticides. The recoveries were in the range from 71. 2% to 122. 4% at the spiked levels of 0. 005,0. 01,0. 05 and 0. 5 mg / kg with the relative standard devi-ations ranging from 0. 5% to 8. 9% in actual samples. The results indicate that the developed method is simple,efficient and precise,and can be a reliable technique for the determination of the five imidazole pesticides in fruit samples.