Abstract:Aiming at temperature effect on stripping peak current of water cadmium analyzer based on anodic stripping voltammetry, a modified simultaneous calibration method is proposed. In the proposed method, standard solutions are simultaneously measured in the period of sample measurement. And sample concentration is calculated by linear comparison of standard solutions and sample stripping peaks. Experimental results indicate the current of cadmium stripping peaks gradually enhanced with temperature increased, while the current of stripping peak increases about 2.3 times from 5.0°C to 43°C. Diffusion rate of cadmium ions within diffusion layer on working electrode surface is dominated by the solution temperature, which is the main mechanism of temperature effect on stripping peak currents. A modified simultaneous calibration method used for analyzer is introduced to eliminated this effect. Test results show that the measurement errors are less than 10% ranged from 5.0°C to 43°C with this simultaneous calibration method, which proves the efficiency in avoiding environmental effect on measured values.