Title: Determination of Lead Pb Concentration in a Local River Water Sample Using Atomic Absorption SpectroscopyObjective: To determine the concentration of lead Pb in a water sample collected from a local river and compare it to the maximum permissible limit set by the World Health Organization WHO .Introduction: Atomic absorption spectroscopy AAS is a widely used technique for the quantitative determination of trace elements in various samples. In this study, AAS was employed to analyze the concentration of lead Pb in a water sample collected from a local river. The results were then compared to the WHO's maximum permissible limit for lead in drinking water.Instrumental Parameters:1. Instrument: Atomic Absorption Spectrometer2. Wavelength: 283.3 nm specific for lead 3. Lamp: Hollow cathode lamp Pb 4. Slit width: 0.5 nm5. Flame type: Air-acetylene6. Sample aspiration rate: 3-5 mL/minExperimental Procedure:1. Collection of water sample: A water sample was collected from a local river in a clean polyethylene bottle and stored at 4C until analysis.2. Preparation of calibration standards: A stock solution of 1000 ppm lead Pb was prepared by dissolving an appropriate amount of lead nitrate in deionized water. A series of calibration standards 0, 1, 5, 10, 20, and 50 ppb were prepared by diluting the stock solution with deionized water.3. Sample preparation: The water sample was filtered through a 0.45 m membrane filter to remove any suspended particles. An aliquot of the filtered sample was acidified with 1% v/v nitric acid to prevent precipitation of lead salts.4. Instrument calibration: The atomic absorption spectrometer was calibrated using the prepared calibration standards. A calibration curve was obtained by plotting the absorbance values against the lead concentrations of the standards.5. Sample analysis: The prepared water sample was aspirated into the flame of the atomic absorption spectrometer, and the absorbance was measured at 283.3 nm. The lead concentration in the sample was determined using the calibration curve.Results:1. Calibration curve: A linear calibration curve was obtained with a correlation coefficient R of 0.999.2. Sample analysis: The absorbance of the water sample was measured to be 0.125. Using the calibration curve, the lead concentration in the sample was determined to be 8.5 ppb.Conclusion:The concentration of lead Pb in the water sample collected from the local river was found to be 8.5 ppb. According to the World Health Organization, the maximum permissible limit for lead in drinking water is 10 ppb. Therefore, the lead concentration in the analyzed water sample is below the WHO's limit, but it is still advisable to monitor and control the sources of lead contamination to ensure the safety of the water supply.