整体柱固相萃取-液相色谱-串联质谱法在线分析大米中15种酰胺类除草剂残留量

以疏水的聚（甲基丙烯酸丁酯-乙二醇二甲基丙烯酸酯）整体柱作为固相萃取柱，建立了大米中15种酰胺类除草剂残留的在线固相萃取结合高效液相色谱-串联质谱测定的方法。本方法采用乙腈提取目标化合物，经在线整体柱净化，Hypersil GOLD色谱柱分离，流动相采用0.5%（v/v）甲酸水溶液-乙腈进行梯度洗脱，在电喷雾正离子模式下以多反应监测（MRM）方式测定。15种除草剂的线性关系良好，相关系数（r）大于0.998。方法检出限和定量限为0.20~2.0 μg/kg和0.50~5.0 μg/kg。待测物在2.0、5.0、10.0、50.0 μg/kg（敌稗为5.0、10.0、50.0、100 μg/kg）4个浓度水平下加标回收率为75.5%~121.3%，相对标准偏差为2.89%~12.38%。该方法快速简便，灵敏度高，可用于大米中酰胺类除草剂的快速定性定量分析。

Determination of 15 amide herbicides in rice using monolith column for on-line solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry

A method based on on-line solid-phase extraction (SPE) coupled with high performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of 15 amide herbicides in rice. A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was utilized as the solid-phase column. The sample was extracted with acetonitrile, cleaned up with the monolithic column in online mode. Subsequently, the analyte was eluted from the extraction column onto the analytical column (Hypersil GOLD column) by 0.5%(v/v) formic acid aqueous solution-acetonitrile in gradient elution mode. Electrospray ionization mass spectrometry was performed in the positive mode and multiple reaction monitoring (MRM) mode. Under the optimized conditions, good linearities were obtained with correlation coefficients of more than 0.998. The limits of detection (LODs) and limits of quantification (LOQs) were in the range 0.20-2.0 μg/kg and 0.50-5.0 μg/kg, respectively. The average recoveries were in the range 75.5% to 121.3% at spiked levels of 2.0, 5.0, 10.0, and 50.0 μg/kg for 14 amide herbicides and 5.0, 10.0, 50.0, and 100.0 μg/kg for propanil. The relative standard deviations ranged from 2.89% to 12.38%. The proposed method is simple, rapid, and highly sensitive, and it can be applied to the simultaneous identification and quantification of the 15 amide herbicides in rice.