To determine the concentration of lead Pb in a water sample collected from a nearby river using atomic absorption spectroscopy AAS , you will need to follow these steps:1. Collect the water sample: Obtain a representative water sample from the river, ensuring that it is collected and stored in a clean container to avoid contamination.2. Prepare the sample: Filter the water sample to remove any suspended particles or debris. This can be done using a syringe filter or a vacuum filtration system.3. Calibration: Prepare a series of lead Pb standard solutions with known concentrations, typically in the range of 0 to 50 ppb parts per billion . These standards will be used to create a calibration curve, which will help you determine the concentration of lead in the water sample.4. Measure absorbance: Use the atomic absorption spectrometer to measure the absorbance of each standard solution and the water sample. The instrument will atomize the sample and expose it to a light source with a specific wavelength that corresponds to the absorption of lead. The absorbance is directly proportional to the concentration of lead in the sample.5. Create a calibration curve: Plot the absorbance values of the standard solutions against their respective concentrations. This will create a calibration curve, which can be used to determine the concentration of lead in the water sample.6. Determine the concentration of lead in the water sample: Find the absorbance value of the water sample on the calibration curve and determine the corresponding concentration of lead.7. Report the results: Report the concentration of lead in the water sample, typically in units of ppb parts per billion or g/L micrograms per liter .Please note that this is a general outline of the process, and specific details may vary depending on the equipment and protocols used in your laboratory.