基于高效液相色谱法对农产品中吡虫啉的提取和净化

基于高效液相色谱法，对不同农产品中吡虫啉的不同提取和净化方法进行比较，建立农产品中吡虫啉农药残留的检测方法。样品经乙腈提取后，采用WondaSep GC-e/PSA固相萃取柱净化，以乙腈-0.1%磷酸为流动相梯度洗脱，XBridge C18色谱柱进行分离，二极管阵列检测器检测，外标法定量。考察不同农产品加水或不加水提取对吡虫啉提取的影响，以及固相萃取和QuEChERS对干扰基质的净化效果。研究表明：不同提取方法和净化方法，对不同农产品影响差异较大。该方法中吡虫啉在0.05～10.0 μg/mL范围内线性关系良好（R2≥0.999），平均回收率在88.3%～109.1%之间，相对标准偏差不大于3.5%。本研究可为农产品中吡虫啉农药残留的监测提供技术支持。

Comparison of Sample Pretreatment Methods for the Determination of Imidacloprid Residue in Agricultural Products by High Performance Liquid Chromatography

The aim of this study was to develop a high performance liquid chromatography (HPLC) method for the determination of imidacloprid residue in agricultural products. Different extraction and purification methods were compared for their applicability in the sample pretreatment procedure. Samples were extracted with acetonitrile and the extract was concentrated and purified using a WondaSep GC-e/PSA SPE cartridge. The target compound was separated on an XBridge C18 column using 0.1% phosphoric acid-acetonitrile as the mobile phase under gradient elution mode, detected with a diode-array detector and quantified by external standard method. The effect of water added to agricultural products on the extraction of imidacloprid was examined, and solid phase extraction (SPE) and the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method were compared for their efficiency in removing interfering matrices. The results showed that different extraction and purification methods had different effects on different agricultural products. The method developed in this study showed good linearity with correlation coefficients (R2) greater than or equal to 0.999 in the concentration range of 0.05 to 10.0 μg/mL. The average recoveries of the analyte were between 88.3%–109.1%, with relative standard deviations (RSDs) less than 3.5%. This method can provide strong technical support for the monitoring of imidacloprid residues in agricultural products.