聚吡咯-离子液体固相微萃取涂层的电沉积制备及其在苯类化合物气相色谱检测中的应用

在0.1 mol/L吡咯-0.1 mol/L对甲苯磺酸-4g/L 1-丁基-3-甲基咪唑四氟硼酸盐水溶液中,通过循环伏安法在不锈钢丝表面制备了新型聚吡咯-离子液体(Polypyrrole-ionic liquid,PPY-IL)涂层.此涂层呈菜花状结构,粒度比PPY小.以5种苯类化合物(即1,2-二甲苯、1,2,4-三氯苯、1,2-二氯苯、1,2,4-三甲苯和1,3,5-三甲苯)为目标分析物,对所得萃取头性能进行了考察.在优化的实验条件(萃取温度:50℃；萃取时间:40 min;搅拌速率:600 r/min; NaCl浓度:0.2 g/mL)下,对这些苯类化合物进行顶空固相微萃取-气相色谱检测,其线性范围为0.6～800 μg/L,单根多次萃取的相对标准偏差小于4.5％(n=5),多根萃取头平行萃取的相对标准偏差为4.5％～12.4％(n=5).PPY-IL萃取头有良好的稳定性,在使用150次后萃取性能仅有很小的变化；在温度升至290℃时不分解.与聚吡咯和聚二甲基硅氧烷萃取头相比,本萃取头对这些苯类化合物有更高的萃取能力.

Electrochemical Preparation of Polypyrrole-Ionic Liquid Coating for Solid Phase Microextraction and Its Application in Gas Chromatographic Determination of Benzene Derivatives

A novel polypyrrole-ionic liquid(PPY-IL) film coated steel wire was prepared by electrodeposition in 0.1 mol/L pyrrole+0.1 mol/L p-methyl benzene sulfonate acid+4 g/L 1-butyl-3-methylimidazolium tetrafluoroborate aqueous solution.The PPY-IL coating showed cauliflower structure,with smaller particle size than that of polypyrrole.Taking five benzene derivatives as models,the analytical performance of the resulting fiber was explored.Under the optimized conditions(i.e.extraction temperature:50 ℃;extraction time:40 min;stirring rate:600 r/min;NaCl concentration:0.2 g/mL),when the benzene derivatives were determined by GC after headspace solid-phase microextraction with the PPY-IL fiber,the linear ranges were 0.6-800 μg/L with correlation coefficients above 0.99.The relative standard deviations(RSD) of chromatographic peak areas were smaller than 4.5% for five successive extraction with single fiber,and the RSDs for fiber-to-fiber were 4.5-12.4%(n=5) for different benzene derivatives.The fiber also presented good stability and it still had high extraction efficiency after being used for about 150 times;when the temperature was up to 290 ℃ it did not decompose.In comparison with PPY and polydimethylsiloxane fibers,the PPY-IL fiber showed higher extraction capability and durability.