To determine the amount of lead present in a water sample collected from a local river using atomic absorption spectroscopy AAS , you will need to follow these steps:1. Collect the water sample: Take a representative water sample from the river, ensuring that it is collected in a clean and appropriate container.2. Prepare the sample: Depending on the concentration of lead in the sample, it may be necessary to dilute the sample or perform a pre-concentration step to bring the lead concentration within the working range of the AAS instrument.3. Prepare calibration standards: Prepare a series of lead calibration standards with known concentrations within the working range of the AAS instrument. These standards will be used to create a calibration curve, which will be used to determine the concentration of lead in the water sample.4. Measure the absorbance of the calibration standards: Using the AAS instrument, measure the absorbance of each calibration standard at the specific wavelength for lead usually around 283.3 nm . Record the absorbance values.5. Create a calibration curve: Plot the absorbance values of the calibration standards against their respective lead concentrations. Fit a linear regression line to the data points, and calculate the equation of the line y = mx + b, where y is the absorbance, x is the concentration, m is the slope, and b is the y-intercept .6. Measure the absorbance of the water sample: Using the AAS instrument, measure the absorbance of the prepared water sample at the specific wavelength for lead. Record the absorbance value.7. Calculate the lead concentration in the water sample: Using the equation of the calibration curve, substitute the absorbance value of the water sample y and solve for the concentration x . This will give you the concentration of lead in the water sample.8. Report the result: Report the concentration of lead in the water sample, including any appropriate units e.g., micrograms per liter, g/L and an estimate of the uncertainty associated with the measurement.Please note that this is a general outline of the procedure, and specific details may vary depending on the AAS instrument and sample preparation methods used.