三正辛胺修饰电极伏安测定痕量金的研究

Studies on Voltammetry Determinatibn of Trace Amount of Gold by Tri-n-Octylamine Modified Electrode

用化学修饰电极伏安测定痕量金,Kalcher K等曾采用阴离子交换剂碳糊修饰电极及打萨宗碳糊修饰电极检测100～300μg/L的金。本文采用三正辛胺(TOA)修饰玻碳电极,在1.5 mol/L介质中,Au(Ⅲ)在+0.16 V(vs SCE)处有一灵敏的不可逆还原峰。检出限为0.1μg/L。灵敏度比文献方法高千倍。Au(Ⅲ)浓度在5×10^(-7)～5×10^(-9)

The determination of trace amount gold( Ⅲ ) with tri-n-octylamine as the modified glassy carbon electrode in 1. 5 mol/L hydrochloric acid medium by cathodic voltammetry is presented. A highly sensitive irreversible reduction peak was obtained at potential +0. 16V(vs SCE). A linear relationship between the peak height and concentration in the range of 5× 10-7-5× 10-9 mol/L of gold was observed. The detection limit was found to be about 0.1 μg/mL (3-min preconcentration). This method is applied to measure the trace amount of gold in anode mud and the results are satisfied, with the coefficient of variation 6. 42%(at 26 ppb level) and the percentage of recovery 95%-101 %.