If you want to know the details of preparatory and measurement procedures, you need to refer to books in this field and publications of institutions dealing with these fields of analysis, and the easiest way is to read the texts of official standards of the country.

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How to determine the concentration of heavy metals in soil, water and plant by using AAS?

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Determining the concentration of heavy metals in soil, water, and plants using Atomic Absorption Spectroscopy (AAS) involves a series of steps. AAS is a widely used analytical technique that measures the absorption of light by atoms in the gas phase. Here's a general outline of the process:

Sample Collection and Preparation:

Soil: Collect representative soil samples from different locations in the area of interest. Air-dry and homogenize the samples, then grind them to a consistent particle size.

Water: Collect water samples from various sources, making sure to preserve their integrity by using appropriate containers and storage techniques.

Plants: Harvest the plant samples, ensuring that you collect different parts (roots, stems, leaves, etc.) depending on your study objectives. Wash and clean the samples to remove any contaminants.

Digestion:

Soil: Since heavy metals can be bound to soil particles, you need to extract them. Use appropriate digestion methods to extract the metals from the soil. Common methods include acid digestion (using concentrated acids) or microwave-assisted digestion.

Water: In some cases, water samples might need pre-concentration or extraction steps to achieve detectable levels of heavy metals.

Plants: Digest the plant samples using suitable methods to break down the organic matter and release the metals. Microwave digestion or wet digestion methods are often employed.

Calibration Standards:

Prepare a series of standard solutions containing known concentrations of the heavy metals you want to analyze. These solutions will be used to create a calibration curve.

Instrument Setup:

Prepare the AAS instrument according to the manufacturer's instructions. This involves optimizing parameters such as wavelength, lamp current, slit width, and flame type.

Measurement:

Inject a small volume of each sample (including standards) into the AAS instrument.

The instrument will emit light at the characteristic absorption wavelength of each metal atom. The amount of light absorbed is proportional to the concentration of the metal present.

Calibration Curve:

Plot the absorbance values of the standards against their known concentrations to create a calibration curve. This curve will be used to quantify the concentration of heavy metals in your samples.

Sample Analysis:

Measure the absorbance of your sample solutions using the AAS instrument.

Refer to the calibration curve to determine the concentration of heavy metals in your samples.

Quality Control:

Run quality control samples (blanks, duplicates, certified reference materials) to ensure the accuracy and precision of your measurements.

Data Interpretation:

Calculate the concentration of heavy metals in your samples based on the calibration curve and instrument readings.

Reporting:

Present your results in a clear and organized manner, including details of your methods, sample preparation, instrument parameters, calibration curve, and the concentrations of heavy metals in your samples.

Remember that AAS requires careful sample preparation, appropriate standards, and proper instrument calibration to yield accurate results. Always follow established protocols and guidelines for handling hazardous materials and operating the AAS instrument.

Only after you are able to formulate more specific questions will it be worth asking them in this forum.

All these methods are available online. For plants use the AOAC (Association of Official Analytical Chemists). For waters and soils use methods of the USEPA (United States Environmental Protection Agency)! These methods involve all means of AAS including graphite furnace (GFAAS for Lead) and cold vapour (CVAAS) for Mercury (and maybe Selenium and Arsenic)