Department of Chemistry, National Chung-Hsing University, Taichung 402, Taiwan.
J Chromatogr A. 2010 Mar 19;1217(12):1891-7. doi: 10.1016/j.chroma.2010.01.076. Epub 2010 Feb 1.
A microwave-assisted headspace controlled-temperature liquid-phase microextraction (HS-CT-LPME) technique was applied for the one-step sample extraction of hexachlorocyclohexanes (HCHs) from aqueous samples with complicate matrices, followed by gas chromatographic (GC) analysis with electron capture detector (ECD). Microwave heating was applied to accelerate the evaporation of HCHs into the headspace and an external-cooling system was used to control the temperature in the sampling zone for HS-LPME. Parameters affecting extraction efficiency, such as LPME solvent, sampling position and temperature, microwave power and irradiation time (the same as sampling time), sample pH, and salt addition were thoroughly investigated. From experimental results, the following conditions were selected for the extraction of HCHs from 10-mL water sample (pH 2.0) by using 1-octanol as the LPME solvent, with sampling done at 38 degrees C for 6 min under 167 W of microwave irradiation. The detections were linear in the concentration of 0.1-10 microg/L for alpha-HCH and gamma-HCH, and 1-100 microg/L for beta-HCH and delta-HCH. Detection limits were 0.05, 0.4, 0.03 and 0.1 microg/L for alpha-, beta-, gamma- and delta-HCH, respectively. Environmental water samples were analyzed with recovery between 86.4% and 102.4% for farm-field water, and between 92.2% and 98.6% for river water. The proposed method proved to serve as a simple, rapid, sensitive, inexpensive, and eco-friendly procedure for the determination of HCHs in aqueous samples.
微波辅助顶空控温液相微萃取（HS-CT-LPME）技术被应用于从复杂基质的水样中一步提取六氯环己烷（HCHs），然后进行气相色谱（GC）分析，采用电子捕获检测器（ECD）。微波加热被应用于加速 HCHs 蒸发到顶空，外部冷却系统被用于控制采样区的温度以进行 HS-LPME。对影响萃取效率的参数，如 LPME 溶剂、采样位置和温度、微波功率和照射时间（与采样时间相同）、样品 pH 值和加盐等进行了深入研究。从实验结果中选择了以下条件，用于从 10-mL 水样（pH 2.0）中萃取 HCHs，采用 1-辛醇作为 LPME 溶剂，在 167 W 的微波辐射下，在 38°C 下采样 6 分钟。α-HCH 和 γ-HCH 的浓度在 0.1-10μg/L 范围内呈线性，β-HCH 和 δ-HCH 的浓度在 1-100μg/L 范围内呈线性。α-、β-、γ-和 δ-HCH 的检测限分别为 0.05、0.4、0.03 和 0.1μg/L。农田水的回收率为 86.4%-102.4%，河水的回收率为 92.2%-98.6%，对环境水样进行了分析。该方法被证明是一种简单、快速、灵敏、经济实惠且环保的水样中 HCHs 测定方法。
