To determine the concentration of lead in a soil sample using atomic absorption spectroscopy AAS , follow these steps:1. Sample collection and preparation: a. Collect a representative soil sample from the area of interest. Make sure to use a clean, dry, and non-contaminated container for sample storage. b. Dry the soil sample in an oven at 105C for 24 hours to remove moisture. c. After drying, grind the soil sample to a fine powder using a mortar and pestle or a mechanical grinder. This will ensure homogeneity and increase the surface area for better extraction of lead.2. Extraction of lead from the soil sample: a. Weigh a known amount of the prepared soil sample e.g., 1 gram and transfer it to a digestion vessel. b. Add a suitable acid mixture e.g., a combination of nitric acid and hydrochloric acid to the digestion vessel to dissolve the lead present in the soil sample. This process is called acid digestion. c. Heat the digestion vessel on a hot plate or in a microwave digestion system until the sample is completely digested and a clear solution is obtained.3. Sample preparation for AAS analysis: a. Filter the digested sample to remove any undissolved particles. b. Dilute the filtered sample to a known volume e.g., 100 mL with deionized water. This will help in bringing the lead concentration within the working range of the AAS instrument.4. Atomic absorption spectroscopy analysis: a. Calibrate the AAS instrument using a series of standard lead solutions with known concentrations. This will help in establishing a calibration curve. b. Aspirate the prepared soil sample solution into the AAS instrument. The instrument will measure the absorbance of the lead in the sample. c. Determine the concentration of lead in the sample by comparing its absorbance with the calibration curve.To ensure accurate and precise results, consider the following measures:1. Use clean glassware and equipment to avoid contamination.2. Perform a blank digestion and analysis to account for any background interference.3. Use a method of standard additions to account for matrix effects and improve accuracy.4. Analyze multiple replicates of the soil sample to ensure precision and reproducibility.5. Regularly maintain and calibrate the AAS instrument to ensure its proper functioning.6. Use appropriate quality control measures, such as analyzing certified reference materials and including control samples in the analysis.