Application of Stripping Voltammetry with a Solid Amalgam Electrode for Determination of Copper in a Tracer and Groundwater Tracing Experiment

Using water-soluble metal salts as tracers, provides an effective method for karst groundwater tracing experiments, which reveal the motion law of karst groundwater by the instant determination of metal ions with artificial tracers in the field. Liquid mercury used in traditional polarography is inconvenient to operate and easily pollutes the environment. In this work, a solid amalgam electrode was made and used for the determination of copper ion in groundwater tracer by stripping voltammetry, in which method the buffer solution of HAc-NaAc was added to the groundwater sample and potassium chloride solution was used as a supporting electrolyte, while the solid amalgam electrode sweeping was employed and the stripping diagram was recorded. Effects of the amount of potassium chlorate solution and HAc-NaAc buffer solution on peak current with a concentration of 100 ng/mL copper standard solution were studied. Copper concentration in the range of 0-1000 ng/mL demonstrated a good linear relationship with the peak current under the selected optimal conditions. The correlation coefficient was greater than 0.999, the detection limit was 0.58 ng/mL and the addition standard recoveries were 96.4%-101.7%. The results were not interfered with by the ions possibly existing in groundwater. When applied to groundwater tracing experiments, stripping voltammetry results for copper ions agree well with those obtained by polarography. This method provides a simple and rapid procedure, which is suitable for field spot determination while avoiding pollution by liquid mercury.