Simultaneous Determination of Zinc and Cadmium in Radix Salvia Miltiorrhiza by Carbon Fiber Electrode with Stripping Voltammetry / 世界科学技术-中医药现代化

ABSTRACT

This study was aimed to develop a simultaneous determination of zinc and cadmium with carbon fiber electrode by linear sweep stripping voltammetry. Effects of analytical base solution, accumulation potential, ac-cumulation time and scanning velocity were also investigated on the determination. The results showed that in 1 mol·L-1 H2SO4 medium solution, zinc and cadmium had good electrochemical response on the carbon fiber electrode and appeared sensitive anodic stripping peaks at-0.97 V and-0.77 V, respectively. The anodic stripping peak cur-rents and concentrations of zinc and cadmium showed good linear relationships, with correlation coefficients R2 of 0.996 5 and 0.995 4, respectively. The detection limits of zinc and cadmium (S/N=3) were 1.5×10-9 mol·L-1 and 1.0×10-10 mol·L-1, respectively. The average recoveries of zinc and cadmium were 98.9%and 98.1%with the rela-tive standard deviations (RSD) of 2.72%and 2.45%(n=6), respectively. It was concluded that the method of simul-taneous determination of zinc and cadmium with carbon fiber electrode was simple, sensitive and accurate.