Cyclic voltammetry is an electroanalytical technique that can be used to determine the concentration of various metal ions, including lead Pb , in water samples. The method involves applying a potential to an electrode and measuring the resulting current as the potential is varied. The current response can be correlated to the concentration of the analyte in this case, lead in the sample.Here is a step-by-step procedure to determine the concentration of lead Pb in a water sample using cyclic voltammetry:1. Prepare the water sample: Collect the water sample and filter it to remove any particulate matter. If necessary, adjust the pH of the sample to the desired range usually between 4 and 6 using appropriate buffer solutions.2. Prepare the working electrode: Clean the working electrode typically a glassy carbon electrode or a mercury film electrode by polishing it with alumina slurry and rinsing it with deionized water. Dry the electrode with a gentle stream of nitrogen gas.3. Prepare the electrochemical cell: Assemble the electrochemical cell, which typically consists of a working electrode, a reference electrode such as Ag/AgCl or saturated calomel electrode , and a counter electrode such as a platinum wire . Fill the cell with the water sample.4. Add supporting electrolyte: Add an appropriate supporting electrolyte such as potassium chloride or sodium nitrate to the water sample to ensure sufficient ionic strength and conductivity.5. Perform cyclic voltammetry: Connect the electrodes to a potentiostat and perform cyclic voltammetry by applying a potential sweep between a starting potential and a final potential for lead, typically between -0.5 V and -1.2 V vs. the reference electrode . The potential is swept at a constant scan rate e.g., 50 mV/s . Record the resulting current-potential curve voltammogram .6. Identify the peak current: Analyze the voltammogram to identify the peak current corresponding to the reduction of lead ions Pb2+ to metallic lead Pb . This peak typically appears at a potential around -0.5 V to -0.6 V vs. the reference electrode.7. Calibration curve: Prepare a series of standard solutions containing known concentrations of lead ions. Perform cyclic voltammetry on each standard solution and plot the peak current vs. the concentration of lead ions to obtain a calibration curve.8. Determine the concentration of lead in the sample: Measure the peak current for the water sample and use the calibration curve to determine the concentration of lead ions in the sample.9. Validate the results: To ensure the accuracy of the results, perform additional validation steps, such as analyzing the sample using other analytical techniques e.g., atomic absorption spectroscopy or inductively coupled plasma mass spectrometry or comparing the results with certified reference materials.By following these steps, you can determine the concentration of lead Pb in a water sample using cyclic voltammetry.