离子液体掺杂聚苯胺固相微萃取涂层的电沉积制备及其在芳香胺检测中的应用

Electrochemical Preparation of Polyaniline-Ionic Liquid Based Solid Phase Microextraction Coating and Its Application in Determination of Aromatic Amines

新型萃取材料及相关涂层制备技术是固相微萃取技术发展的重点。本研究在1-羟丙基-3-甲基咪唑-四氟硼酸盐([C3(OH)mim][BF4])和HNO3混合溶液中,通过电化学方法在铂(Pt)丝表面固定新型聚苯胺-离子液体(PANI-IL)涂层。电镜分析表明,离子液体存在时,PANI膜孔结构变均匀、比表面积增大。以芳香胺为模拟物,考察萃取头的顶空固相微萃取(HS SPME)性能。在优化条件下,5种芳香胺的检出限为0.04～0.12μg/L(S/N=3);线性范围为0.15～1000μg/L。同一萃取头萃取5次的相对标准偏差(RSD)小于4.6%;不同萃取头的RSD则在2.4%～9.5%(n=3)之间。与自制聚苯胺(PANI/Pt)及商品化的聚丙烯酸酯(PA)萃取头相比,PANI-IL/Pt萃取头具有更高的萃取率。此外,PANI-IL涂层对苯类化合物亦有较高的萃取能力。萃取头使用120余次后,萃取性能无明显变化,表明萃取头的稳定性好、使用寿命长。

A novel solid phase microextraction coating of polyaniline-ionic liquid（PANI-IL） was prepared by electrodeposition on a Pt wire in aqueous solutions containing ionic liquid [C3（OH）mim] and nitric acid.The resulted coating was more uniform and porous than PANI coating.Taking five aromatic amines as models,the performance of the PANI-IL/Pt fiber was explored.Under the optimized conditions,when they were determined by GC after headspace SPME with the PANI-IL/Pt,the detection limits were 0.04-0.12μg/L（S/N=3） and the linear ranges were 0.15-1000 μg/L.These aromatic amines were determined for five times using a PANI-IL/Pt fiber coupled with GC and the RSD of chromatographic peak areas were smaller than 4.6%;the fiber to fiber RSD was 2.4-9.5% for different aromatic amines.In comparison with PANI/Pt and commercial PA,the PANI-IL/Pt fiber showed higher extraction efficiency and repeatability.It also exhibited high extraction capability to benzene compounds.The PANI-IL/Pt fiber was used for more than 120 times,its extraction efficiency was almost unchanged,exhibiting good stability and long life time.