一滴溶剂微萃取-毛细管气相色谱法分析水中的七种硝基苯类化合物

用一滴溶剂微萃取(SDME)-毛细管气相色谱联用技术测定水中的硝基苯、硝基甲苯类和硝基氯苯类化合物,对影响萃取的因素如萃取溶剂种类、液滴体积、搅拌速度、针尖入水深度、水样体积、萃取时间、萃取温度等进行了优化,结果表明:硝基苯和硝基甲苯类化合物在0.8～32 μg/L 范围内,硝基氯苯类化合物在0.04～3.2 μg/L 范围内均呈现良好的线性(r2>0.999),检出限可达0.01～0.3 μg/L。自来水加标样品测定的相对标准偏差和平均回收率(n=5)范围分别为3.1%～7.9%和101%～105%,废水加标样品测定的相对标准偏差和平均回收率(n=5)范围分别为3.3%～7.9%和92.5%～97.0%。优化后的SDME具有环保、灵敏、快速、简便等特点,适用于萃取水中的痕量硝基苯、硝基甲苯类和硝基氯苯类化合物。

Determination of Seven Nitrobenzene Compounds in Water Samples by Single-Drop Microextraction with Capillary Gas Chromatography

A method suitable for the extraction of nitrobenzene, nitrotoluenes and nitrochlorobenzenes from water samples using single-drop microextraction with capillary gas chromatography is presented. Parameters, such as organic solvents, drop volume of organics, agitation, immerge depth of needle point, aqueous sample volume, exposure time and temperature were controlled and optimized. The developed protocol was found to yield a linear calibration curve in a concentration range from 0.8 to 32 microg/L for nitrobenzene and nitrotoluenes and a range from 0.04 to 3.2 microg/L for nitrochlorobenzenes (r2 > 0.999). The limits of detection were found to be in the range between 0.01 and 0.3 microg/L. The relative standard deviations (RSDs) and relative recoveries (n = 5) from tap water fortified samples were 3.1% -7.9%, and 101% - 105%, and from waste water fortified samples were 3.3% - 7.9%, and 92.5% - 97.0%, respectively. The single-drop microextraction is proved to be a environmental friendly, sensitive, fast and simple tool for the preconcentration of trace nitrobenzene, nitrotoluenes and nitrochlorobenzenes from water samples.