Polarography is an electroanalytical technique that can be used to quantify the amount of copper ions in a water sample. The technique is based on measuring the current that flows between two electrodes working and reference electrodes when a potential is applied. The current is proportional to the concentration of the analyte in this case, copper ions in the solution. Here's a step-by-step procedure to quantify the amount of copper ions in a water sample using polarography:1. Sample preparation: Collect the water sample and filter it to remove any suspended particles. Acidify the sample with concentrated nitric acid HNO3 to prevent the precipitation of copper ions and to stabilize the sample.2. Calibration: Prepare a series of standard solutions containing known concentrations of copper ions. These solutions will be used to create a calibration curve, which will help in determining the concentration of copper ions in the water sample.3. Electrode preparation: Clean the working electrode usually a dropping mercury electrode, DME and the reference electrode e.g., Ag/AgCl electrode before starting the analysis.4. Supporting electrolyte: Prepare a supporting electrolyte solution, such as potassium chloride KCl or sodium acetate CH3COONa , to maintain a constant ionic strength in the solution and to minimize the effect of other ions present in the sample.5. Add complexing agent: Add a suitable complexing agent, such as diethyldithiocarbamate DDTC , to the sample and standard solutions. This agent forms a stable complex with copper ions, which can be easily reduced at the working electrode.6. Polarographic measurements: Carry out the polarographic measurements using a polarograph. Set the applied potential range and scan rate according to the literature values for the reduction of copper-DDTC complex. Record the current-potential curves polarograms for the standard solutions and the water sample.7. Calibration curve: Plot the peak current values obtained from the polarograms of the standard solutions against their respective copper ion concentrations. This will give you a calibration curve.8. Determine the concentration of copper ions in the water sample: Measure the peak current value for the water sample from its polarogram. Use the calibration curve to determine the concentration of copper ions in the water sample.9. Quality control: To ensure the accuracy and reliability of the results, perform replicate measurements, spike recovery tests, and use certified reference materials if available.By following these steps, you can successfully quantify the amount of copper ions in a water sample using the polarography technique.