The concentration of lead Pb in a given water sample can be determined using atomic absorption spectroscopy AAS by following these steps:1. Sample preparation: Collect a representative water sample and filter it to remove any suspended particles. Acidify the sample with a few drops of concentrated nitric acid HNO3 to prevent precipitation of lead salts and preserve the sample.2. Calibration: Prepare a series of lead standard solutions with known concentrations by diluting a lead stock solution with deionized water. These standard solutions will be used to create a calibration curve.3. Instrument setup: Set up the atomic absorption spectrometer according to the manufacturer's instructions. Choose the appropriate lamp hollow cathode lamp or electrodeless discharge lamp for lead determination and set the wavelength to the optimal value for lead usually around 283.3 nm .4. Calibration curve: Measure the absorbance of each lead standard solution using the AAS instrument. Plot the absorbance values against the corresponding lead concentrations to create a calibration curve. Ensure that the curve is linear and has a good correlation coefficient R > 0.99 .5. Sample analysis: Aspirate the prepared water sample into the AAS instrument and measure its absorbance. Compare the absorbance value to the calibration curve to determine the concentration of lead in the sample.To ensure accurate quantification, follow these measures:1. Use a method of standard additions: This involves spiking the water sample with known amounts of lead standard solution and measuring the absorbance of each spiked sample. This can help account for any matrix effects or interferences that may affect the accuracy of the measurement.2. Perform a blank correction: Measure the absorbance of a blank solution deionized water with added nitric acid and subtract this value from the absorbance of the sample and standards to correct for any background absorbance.3. Use a graphite furnace AAS GFAAS instead of flame AAS FAAS if the concentration of lead in the sample is very low. GFAAS has a higher sensitivity and lower detection limit compared to FAAS.4. Ensure that the instrument is properly maintained and calibrated, and that the operating conditions e.g., lamp current, slit width, and burner height are optimized for lead determination.5. Perform replicate measurements and calculate the average concentration to minimize random errors and improve the precision of the results.