聚合离子液体-多壁碳纳米管化学修饰电极同时测定多巴胺、抗坏血酸与尿酸

Simultaneous Determination of Dopamine,Ascorbic Acid and Uric Acid Using Poly(ViEtIm^+Br^-)/MWCNTs/GCE

以1-乙烯基咪唑(1-Vinylimidazole)和1-溴乙烷(1-Bromoethane)为原料设计合成了溴化1-乙烯基-3-乙基咪唑功能化离子液体(1-Vinyl-3-ethylimidazolium bromide),以偶氮二异丁腈(Azobis(2-methylpropionitrile))为引发剂,制备了聚1-乙烯-3-乙基咪唑溴代盐聚合离子液体(Poly(ViEtIm^+Br^-))。在此基础上,利用Poly(ViEtIm^+Br^-)中咪唑基团与多壁碳纳米管之间的强π-π相互作用,在温和条件下,使用非共轭方法制备了聚合离子液体-多壁碳纳米管复合物修饰电极(Poly(ViEtIm^+Br^-)/MWCNTs/GCE),并成功应用于多巴胺(DA)、抗坏血酸(UA)和尿酸(UA)的同时测定。结果表明,在DA、AA、UA 3者的同时存在下,Poly(ViEtIm^+Br^-)/MWCNTs对3者的检测范围分别为2～180μmol/L、50～5 000μmol/L、4～50μmol/L,对应检出限分别为0.4、22.2、0.9μmol/L。将该电极用于维生素C注射剂中抗坏血酸浓度的检测以及盐酸多巴胺注射剂中多巴胺浓度的检测,回收率为98.8%～101%,检测效果良好。

In the present work,functionalized ionic liquid of 1-vinyl-3-ethylimidazolium bromide (ViEtIm^+Br^-) was firstly synthesized by reaction of 1-vinylimidazole and 1-bromoethane.Poly (1-vinyl-3-ethylimidazolium bromide ) polymeric ionic liquid (Poly (ViEtIm^+Br^-)) was obtained through polymerization reaction of (ViEtIm^+Br^-) by using azobis (2-methylpropionitrile ) as initiator.Then,the composite of polymeric ionic liquid modified multi-walled carbon nanotube (Poly (ViEtIm^+Br^-)/MWCNTs ) was prepared under mild conditions through a non-conjugated method by taking advantage of strong π-π interaction between MWCNTs and imidazole group,which was designed as an efficient electrode modifider for the simultaneous determination of UA,DA and UA.The experimental results showed that the Poly (ViEtIm^+Br^-)/MWCNTs/GCE displayed a linear response for DA,AA and UA in the range of 2-180 μmol/L,50-5 000 μmol/L and 4-50 μmol/L,respectively,and the detection limits were 0.4,22.2,0.9 μmol/L,respectively.The Poly (ViEtIm^+Br^-)/MWCNTs/GCE was successfully used for the detection AA in vitamin C injection and DA in dopamine hydrochloride injection with recoveries of 98.8 %-101 %.