Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China.
J Chromatogr A. 2013 Feb 1;1275:25-31. doi: 10.1016/j.chroma.2012.12.036. Epub 2012 Dec 22.
In this work, a new method of polydimethylsiloxane/polythiophene (PDMS/PTH) coated stir bar sorptive extraction (SBSE) coupled to liquid desorption-large volume injection-gas chromatography-flame photometric detection (LD-LVI-GC-FPD) was proposed for the determination of organophosphorus pesticides (OPPs, including phorate, fenitrothion, malathion, parathion and quinalphos) in environmental water samples. Polythiophene was synthesized by chemical oxidative polymerization method, and the PDMS/PTH coated stir bar was prepared by sol-gel technique. The preparation reproducibility of PDMS/PTH coated stir bar was good with the relative standard deviations (RSDs) ranging from 3.9% to 8.1% (n=7) in one batch, and from 5.9% to 14.9% (n=6) among different batches. To get the best extraction performance for OPPs, the operation parameters affecting the extraction efficiency of SBSE, including extraction time, desorption time, stirring rate and ionic strength, were investigated. Under the optimal conditions, the limits of detection (S/N=3) were found to be in the range of 0.011-0.038 μg/L for the five target OPPs, and the linear range was from 0.2 to 100 μg/L for phorate and 0.1-100 μg/L for other four OPPs. The RSDs of the proposed method were in the range of 4.0-9.8% (n=8, c=1 μg/L) and the enrichment factors were varied from 56.7 to 80.9-fold (theory enrichment factor was 100-fold). The proposed method was applied to the analysis of OPPs in East Lake water and ground water samples with recovery in the range of 77.7-119.8% and 79.1-109.8% for the spiked East Lake water and ground water samples, respectively.
在这项工作中，提出了一种新的聚二甲基硅氧烷/聚噻吩（PDMS/PTH）涂层搅拌棒吸附萃取（SBSE）与液体解吸-大体积进样-气相色谱-火焰光度检测（LD-LVI-GC-FPD）联用的方法，用于测定环境水样中的有机磷农药（OPPs，包括甲拌磷、三唑磷、马拉硫磷、对硫磷和喹硫磷）。聚噻吩通过化学氧化聚合法合成，PDMS/PTH 涂层搅拌棒通过溶胶-凝胶技术制备。PDMS/PTH 涂层搅拌棒的制备重现性良好，同一批次的相对标准偏差（RSD）在 3.9%至 8.1%（n=7）之间，不同批次之间的 RSD 在 5.9%至 14.9%（n=6）之间。为了获得 OPPs 的最佳萃取性能，考察了影响 SBSE 萃取效率的操作参数，包括萃取时间、解吸时间、搅拌速度和离子强度。在最佳条件下，五种目标 OPPs 的检出限（S/N=3）在 0.011-0.038μg/L 范围内，甲拌磷的线性范围为 0.2-100μg/L，其余四种 OPPs 的线性范围为 0.1-100μg/L。该方法的 RSD 在 4.0-9.8%（n=8，c=1μg/L）范围内，富集因子变化范围为 56.7-80.9 倍（理论富集因子为 100 倍）。该方法应用于东湖水样和地下水样品中 OPPs 的分析，东湖水样和地下水样品的加标回收率分别在 77.7-119.8%和 79.1-109.8%范围内。
