Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand.
Anal Bioanal Chem. 2011 Sep;401(5):1703-12. doi: 10.1007/s00216-011-5214-x. Epub 2011 Jul 10.
A mixed anionic-cationic surfactant cloud point extraction (CPE) has been developed using sodium dodecyl sulfate (SDS) and tetrabutylammonium bromide (TBABr) for the extraction and preconcentration of organophosphorus pesticides (OPPs) at ambient temperature before analysis by high-performance liquid chromatography. The studied OPPs were azinphos-methyl, parathion-methyl, fenitrothion, diazinon, chlorpyrifos, and prothiophos. The optimum conditions of the mixed anionic-cationic CPE were 50 mmol L(-1) SDS, 100 mmol L(-1) TBABr, and 10% (w/v) NaCl. The extracted OPPs were successfully separated within 11 min using the conditions of a Waters Symmetry C8 column, a flow rate of 0.8 mL min(-1), a gradient elution of methanol and water, and detection at 210 nm. Linearity was found over the range 0.05-5 μg mL(-1), with the correlation coefficients higher than 0.996. The enrichment factor of the target analytes was in the range 6-11, which corresponds to their limits of detection from 1 to 30 ng mL(-1). High precisions (intra-day and inter-day) were obtained with relative standard deviation <1.5% (t(R)) and 10% (peak area). Accuracies (% recovery) of the different spiked OPP concentrations were 82.7-109.1% (water samples) and 80.3-113.3% (fruit juice samples). No contamination by the OPPs was observed in any studied samples.
一种混合阴离子-阳离子表面活性剂浊点萃取（CPE）已被开发出来，用于在环境温度下萃取和预浓缩有机磷农药（OPPs），然后通过高效液相色谱法进行分析。研究的 OPPs 有马拉硫磷、对硫磷、杀螟松、二嗪农、毒死蜱和丙溴磷。混合阴离子-阳离子 CPE 的最佳条件为 50mmol/L SDS、100mmol/L TBABr 和 10%（w/v）NaCl。在 Waters Symmetry C8 柱、流速为 0.8mL/min、甲醇和水梯度洗脱、210nm 检测的条件下，可在 11min 内成功分离萃取的 OPPs。在 0.05-5μg/mL 的范围内发现了线性关系，相关系数高于 0.996。目标分析物的富集因子在 6-11 范围内，其检测限为 1-30ng/mL。高精密性（日内和日间），相对标准偏差<1.5%（t（R））和 10%（峰面积）。不同浓度 OPPs 的加标回收率为 82.7-109.1%（水样）和 80.3-113.3%（果汁样）。在任何研究的样品中都没有观察到 OPPs 的污染。
