气相色谱-串联质谱法检测乙氧氟草醚、唑草酮和乙螨唑在4种香辛料中的残留

Determination of oxyfluorfen, carfentrazone-ethyl and etoxazole residues in four spices using gas chromatography-tandem mass spectrometry

建立了气相色谱-三重四极杆串联质谱(GC-MS/MS)检测留兰香、桂皮、薄荷和月桂叶中乙氧氟草醚、唑草酮、乙螨唑残留的分析方法。4种香辛料用超纯水饱和,乙腈提取,无水硫酸镁及氯化钠盐析,氨基/石墨化碳黑(NH_2-Carb)固相萃取柱净化,多反应监测模式,气相色谱-串联质谱测定。结果表明:乙氧氟草醚在0.002 5～2 mg/L范围内,唑草酮和乙螨唑在0.01～2 mg/L范围内,3种农药的进样质量浓度与对应的峰面积间呈良好的线性关系,r> 0.99;乙氧氟草醚在0.025、0.5和2 mg/kg 3个添加水平下,在4种香辛料中的平均回收率在86%～112%之间,相对标准偏差(RSD)在2.4%～9.6%之间;唑草酮在0.2、0.5和2 mg/kg 3个添加水平下的平均回收率在87%～114%之间,RSD在2.4%～11%之间;乙螨唑在0.5、2和5 mg/kg 3个添加水平下的平均回收率在86%～116%之间,RSD在3.2%～11%之间。乙氧氟草醚、唑草酮和乙螨唑在4种香辛料中的定量限(LOQ)分别为0.025、0.2和0.5 mg/kg。

An analytical method was developed for the determination of oxyfluorfen, carfentrazoneethyl and etoxazole in Mentha spicata L, Cinnamomum cassia Presl, Mentha piperita L, and Laurus nobilis L using gas chromatography-tandem mass spectrometry(GC-MS/MS). The spice matrices were hydrated by ultrapure water, extracted by acetonitrile followed by the salting out process with anhydrous magnesium sulfate and sodium chloride then purified using the NH2-Carb column and determined by the GC-MS/MS under MRM mode. The calibration curve showed a good linearity in the range of 0.0025-2 mg/L(oxyfluorfen) and 0.01-2 mg/L(carfentrazone-ethyl and etoxazole), with the correlation efficient above 0.99. The average recoveries of oxyfluorfen in the four kinds of matrices at three spiked levels of 0.025, 0.5 and 2 mg/kg ranged from 86% to 112%, with the relative standard deviation(RSD) between 2.4%-9.6%. The average recoveries of carfentrazone-ethyl at three spiked levels of 0.2, 0.5 and 2 mg/kg ranged from 87% to 114%, with the RSD between 2.4%-11%. The average recoveries of etoxazole at three spiked levels of 0.5, 2 and 5 mg/kg ranged from 86% to 116%,with the RSD between 3.2%-11%. The limit of quantitation(LOQ) of oxyfluorfen, carfentrazone-ethyl and etoxazole in the four spices were 0.025, 0.2 and 0.5 mg/kg, respectively.