分析科学学报

本研究建立了一种基于石墨化炭黑分散固相萃取结合气相色谱法分析环境水样中菊酯类农药的新方法。方法采用石墨化炭黑作为吸附剂,将其直接分散到水溶液中涡旋,萃取完成后,将水溶液通过一次性过滤头,从而将吸附了目标物的炭黑阻留在滤头中,可避免离心,并简化后续清洗与解吸操作。本文中对样品前处理过程中的吸附时间、吸附剂用量、洗脱溶剂的种类与体积及样品溶液的pH和离子强度等影响萃取效率的因素进行优化,在最优条件下,以黄家湖水为基质,考察该方法的线性关系、检出限、定量限、准确度和精密度等。结果表明,7种目标化合物在2～200μg/L的范围内线性关系良好,相关系数R²均大于0.995,检出限在0.2～0.8μg/L之间,低、中、高3个浓度的加标回收率在79.5%以上,日内日间相对标准偏差(RSD)小于8.8%。将所建立的方法应用于5种类型共10个环境水样的检测,均检出目标分析物,在加标5μg/L的水平下,7种目标分析物的回收率在75.8%～118.9%之间,RSD小于7.3%。本研究所建立的方法前处理时间短、操作简便、所用试剂环保,适用于环境水样中菊酯类农药的残留量分析。

In this study,a new method for detection of pyrethroid pesticides in environmental water samples was developed by graphitized carbon black(GCB) based disperse solid-phase extraction(DSPE) combined with GCECD.In this method,GCB was directly dispersed into water samples.After extraction,the aqueous solution was passed through a disposable filter head for retaining the sorbent that adsorbed the target analytes,which could avoid centrifugation and simplify subsequent washing and desorption operations.Parameters that might affect the extraction efficiency were optimized including the time of adsorption,the amount of sorbent,the type and volume of the eluting solvent,the pH and ionic strength of the sample solution.Under the optimized conditions,seven target analyses had good linear relationship in the range of 2-200 μg/L with R² more than 0.995,and the limits of detection were in the range of 0.2-0.8 μg/L.At the three spiked concentration level of low,medium and high,the recoveries of the seven target analytes were more than 79.5%,and the RSDs were less than 8.8%.Finally,this method was applied to analyze ten environmental water samples in Wuhan.The target analytes can be detected in all real samples,and at the spiked concentration of 5 μg/L,the recoveries were in the range from 75.8% to 118.9% with RSD less than 7.3%.This proposed method could effectively detect pyrethroids residue in environmental water samples with short pretreatment time,simple operation and eco-friendly reagent.