填充吸附微萃取-气相色谱法检测水中有机磷农药

Determination of organophosphorus pesticides in water using microextraction by packed sorbent coupled with gas chromatography

建立了基于填充吸附微萃取（MEPS）和气相色谱检测水中的10种有机磷农药的方法。其中影响MEPS萃取效果的重要参数,如萃取材料、萃取循环次数和萃取速度、洗脱溶剂和洗脱体积、样品pH等均进行了详细测试和优化。最优条件下,先将样品pH调节为2,然后用C18作为萃取材料,以20μL/s的速度进行10次重复萃取,最后用150μL乙酸乙酯进行洗脱。10种目标物在22min内分离良好,并在10~500μg/L范围内线性良好,相关系数范围在0.9940~0.9992,检出限范围为0.1~2.3μg/L。在10和100μg/L两个水平加标实验中,10种有机磷农药的平均回收率为61.5%~104.3%,相对标准偏差为5.5%~15%。

An attractive, fast, low-consumption and very promising high-throughput strategy, based on microextraction by packed sorbent （MEPS） coupling to gas chromatography （GC）, was developed and validated for the determination and quantification of 10 organophosphorus pesticides in water. Important factors affecting the performance of MEPS such as the type of sorbent material, number of extraction cycles, extraction speed, the elution solvent and volume, pH of sample were tested and optimized. The optimal MEPS extraction conditions were obtained using C18 phase as sorbent at a speed of 20 μL/s for 10 extraction cycles after the pH of the sample was adjusted to 2. Finally, the target compounds were eluted by 150 μL of ethyl acetate. The analytical method demonstrated good linearity （ 10 - 500μg/L） with correlation coefficient ranging from 0. 9972 to 0. 9995. The limits of detection of 10 organophosphorus pesticides were in the range of 0.1 - 2.3 μg/L. At the spiked levels of 10 and 100 μg/L, the average spiked recoveries for 10 organophosphorus pesticides were between 61.5% and 104.3%, with relative standard derivations （RSDs） from 5.5% to 14.9%. This new approach offers an attractive alternative for analysis of organophosphorus pesticides in water samples with advantages of simplified preparation process, short-time consumption and portable performing as compared to traditional methodologies.