Atomic absorption spectroscopy (AAS) is widely used in quantitative analysis to determine the concentration of specific metal elements in a sample. It works by measuring how much light (at a specific wavelength) is absorbed by free atoms of the element being analyzed.
Here’s how AAS is used in quantitative analysis:
- Principle
- When a sample containing metal ions is introduced into a flame or graphite furnace, the metal ions are converted into free atoms.
- These atoms absorb light from a lamp that emits the characteristic wavelength of that element.
- The amount of light absorbed is directly proportional to the concentration of the element in the sample.
- Quantitative Measurement
- A calibration curve is made by measuring the absorbance of a series of standard solutions with known concentrations.
- The absorbance of the unknown sample is then compared to the calibration curve to find its concentration.
- Applications
- Environmental analysis: Measuring metals like lead, cadmium, or mercury in water and soil.
- Food industry: Checking mineral content such as iron, calcium, or zinc.
- Clinical analysis: Determining metal levels in blood or urine.
- Industrial quality control: Monitoring metal content in alloys, fuels, or chemicals.
- Advantages
- High sensitivity and accuracy for trace metal analysis.
- Simple and relatively quick method.
- Requires only a small sample amount.
In summary:
AAS is used in quantitative analysis to accurately measure metal concentrations in various samples by relating the amount of light absorbed by atoms to their concentration.