0 votes
31 views
ago in Analytical Chemistry by (270 points)
How can we use voltammetry to accurately quantify the amount of copper (II) ions present in a sample of drinking water?

1 Answer

0 votes
ago by (470 points)
To accurately quantify the amount of copper  II  ions present in a sample of drinking water using voltammetry, follow these steps:1. Sample preparation: Collect a representative sample of the drinking water to be analyzed. Filter the sample to remove any suspended particles or debris that may interfere with the voltammetric analysis.2. Electrode selection: Choose a suitable working electrode for the voltammetric analysis. A glassy carbon electrode or a mercury-based electrode  such as a hanging mercury drop electrode or a thin-film mercury electrode  is commonly used for the determination of copper  II  ions.3. Supporting electrolyte: Prepare a suitable supporting electrolyte solution that does not react with copper  II  ions and provides a stable background current. Common supporting electrolytes for copper  II  ion analysis include acetate buffer, phosphate buffer, or ammonium nitrate.4. Standard addition method: To improve the accuracy of the analysis, use the standard addition method. Prepare a series of standard solutions containing known concentrations of copper  II  ions. Add these standard solutions to aliquots of the drinking water sample to create a calibration curve.5. Voltammetric analysis: Perform the voltammetric analysis using an appropriate technique, such as differential pulse anodic stripping voltammetry  DPASV  or square wave voltammetry  SWV . These techniques involve applying a potential to the working electrode and measuring the resulting current as the potential is varied. The current is proportional to the concentration of the analyte  copper  II  ions  in the sample.6. Calibration curve: Plot the peak current obtained from the voltammetric analysis against the concentration of copper  II  ions in the standard solutions. Fit a linear regression to the data points to obtain a calibration curve.7. Quantification: Use the calibration curve to determine the concentration of copper  II  ions in the drinking water sample. Calculate the concentration by interpolating the peak current obtained from the voltammetric analysis of the sample on the calibration curve.8. Quality control: Perform replicate analyses and include appropriate quality control samples  such as blanks and spiked samples  to ensure the accuracy and precision of the results.By following these steps, voltammetry can be used to accurately quantify the amount of copper  II  ions present in a sample of drinking water.
Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...