羧基化碳纳米管修饰碳糊电极伏安法测定痕量铝

来源期刊：冶金分析2010年第9期

论文作者：李俊华 邝代治 冯泳兰 曾荣英 屈景年

文章页码：18 - 22

关键词：碳糊电极； 阳极吸附伏安法； 铝； 铬蓝黑R

Key words：carbon paste electrode； anodic adsorption voltammetry； aluminum； eriochrome blue black R

摘    要：以羧基化多壁碳纳米管(c-MWCNT)修饰的碳糊电极为工作电极,建立了一种无汞测定痕量铝的新方法。在0.1 mol/L的HAc-NaAc电解液(pH5.2)中,铬蓝黑R(EBBR)在羧基化多壁碳纳米管修饰碳糊电极表面上进行阳极扫描时出现4个溶出峰,其峰电位分别为12mV、130 mV、390 mV、594 mV,加入Al³⁺后第二个波峰电流明显增加,其它峰电流基本不变。该峰属络合物吸附峰,利用该峰可以进行痕量铝的检测。当电位扫速为350 mV/s、富集时间为180 s时,峰电流与铝浓度在2.0×10^-9～5.0×10^-7 mol/L的范围内呈良好线性关系,其相关系数为0.996,检出限可达1.0×10^-9 mol/L。该法用于铝壶水样中铝含量的测定,回收率在98%～105%之间。

Abstract: With carboxylic multiwalled carbon nanotubes (c-MWCNT) modified carbon paste electrode as working electrode,a new mercury-free determination method of trace aluminium was established.Eriochrome blue black R (EBBR) showed four stripping peaks on surface of c-MWCNT modified carbon paste electrode during anode scanning,such as 12 mV,130 mV,390 mV and 594 mV,in 0.1 mol/L HAc-NaAc eletrolyte.When Al³⁺ was added,the current of the second stripping peak increased remarkbly but that of other peaks kept unaltered.The second peak belonged to adsorption peak of complex,which could be used for the detection of trace aluminium.While the accumulation time of Al³⁺ at the modified electrode was 180 s and potential scan rate was 350 mV/s,there was a good linear relationship between peak current and aluminum concentration in the range of 2.0×10^-9-5.0×10^-7 mol/L with a correlation coefficient of 0.996 and detection limit of 1.0×10^-9 mol/L.This proposed method has been applied to the determination of aluminum in actual aluminum kettles water samples and recoveries were from 98% to 105%.