活性炭纤维固相微萃取-气相色谱法测定海水中的硝基苯类和环酮类化合物

建立了自制活性炭纤维固相微萃取与气相色谱联用测定海水中6种硝基苯类和环酮类化合物的分析方法。优化的萃取条件为: 样品中加NaCl至饱和,在1500 r/min速率搅拌下,于60 ℃水浴中顶空萃取30 min,于280 ℃下解吸2 min。方法的线性范围为0.01～400 μg/L,检出限为1.4～3.2 ng/L,相对标准偏差(RSD,n6)为1.4%～7.8%。海水样品中硝基苯类和环酮类化合物的加标回收率和RSD分别为86.3%～101.8%和3.7%～7.8%。应用所建立的方法对东海近岸表层水样进行测定,其中硝基苯、1,3-二硝基苯、2,6-二硝基甲苯的质量浓度分别为0.756,0.944,0.890 μg/L。实验结果表明,该方法简便、高效、无需有机溶剂,适合于海洋水体中硝基苯类和环酮类化合物的分析。

Determination of nitroaromatics and cyclo ketones in sea water by gas chromatography coupled with activated carbon fiber solid-phase micro-extraction

A gas chromatography (GC) coupled with solid-phase micro-extraction using a special activated carbon fiber (ACF) was developed for the analysis of 6 nitroaromatics and cyclic ketones, nitrobenzene (NB), 1,3-dinitrobenzene (1,3-DNB), 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), isophorone, 1,4-naphthaquinone (1,4-NPQ), in sea water samples. The sample was extracted for 30 min under saturation of NaCl at 1500 r/min and 60 ℃ in head space. The desorption was performance at 280 ℃ for 2 min. The linear ranges were from 0.01 to 400 μg/L. The limits of detection (LODs) were 1.4~3.2 ng/L. This method has been successfully applied to the determination of nitroaromatics and cyclic ketones in the sea water samples obtained from East China Sea. The concentrations of nitrobenzene, 1,3-dinitrobenzene and 2,6-dinitrotoluene in the sea water sample were 0.756, 0.944, 0.890 μg/L, respectively. The recoveries were 86.3%~101.8% with the relative standard deviations (RSDs) of 3.7%~7.8%. The method is suitable for analyzing nitroaromatics and cyclic ketones at low concentration levels in sea water samples.