以离子液体1-丁基-3-甲基咪唑-六氟磷酸盐(简写作[C1MIM][PF6])为萃取剂,取水样10mL,加入氯化钠0.15g,待溶解完全后调节其酸度为pH5.0,用悬挂在微量进样器针端的一滴[C1MIM][PF6](1μL)在室温下超声萃取28min。将萃取了多氯联苯(PCB’s)的离子液体液滴在内径扩大至3.5mm的内衬管的气化室内,于280℃解吸1min,即进入毛细管柱进行色谱分离后进行质谱测定。PCB’s的线性范围为10-300ng·L,检出限(3S/N)在1.2~2.3ng·L^-1之间。分析了8个海水样品,并用标准加入法做回收试验,测得回收率在81.5%~104.2%之间。
0. 15 g of NaC1 was dissolved in 10 mL of the water sample in the headspace sample vial and acidity of the solution was adjusted to pH 5.0. It was then extracted ultrasonically for 28 rain by a droplet (1 μL) of ionic liquid of 1-buty-3-methyl-imidazole hexafluorophosphate [C4MIM][PF6 ] hanged at the end of the needle of the microinjector. Polychlorobiphenyls (PCB's) in the ionic liquid droplet were then desorbed at 280 ℃ for 1 rain in the gasification chamber having the inner diameter of its innerlined tube enlarged to 3.5 mm. The gasified PCB's were introduced into the capillary chromatographic column, separated and determined by MS. Linearity for the PCB's was kept in the range of 10-300 ng . L ^-1. Detection limits (3S/N) were found in the range of 1.2-2. 3 ng . L^-1. Eight samples of sea water were analysed by this method, and recovery was tested by adding mixed standard solution to these samples, giving values of recovery in the range from 81.5% to 104. 2%.