What does atomic absorption spectrometry (AAS) measure?

Atomic absorption spectrometry (AAS) is a technique specifically designed to measure the concentration of metal ions in a sample. The method relies on the principle that atoms in a gaseous state can absorb light at specific wavelengths characteristic of each element. When a sample containing metal ions is vaporized, the atoms are excited to a higher energy state by the absorption of light from a lamp that emits radiation at the specific wavelength corresponding to the metal of interest. The amount of light absorbed is directly proportional to the concentration of the metal ions in the sample.

This technique is particularly useful in various fields such as environmental analysis, pharmaceuticals, and food safety, where it is often necessary to quantify trace metal levels in complex mixtures. The precise and sensitive nature of AAS allows for the detection and quantification of even very low concentrations of metals, making it a powerful tool in analytical chemistry.

While it does not measure molecular weight, the presence of functional groups, or thermal stability of compounds, its specificity and sensitivity toward metallic elements form the core of its application, confirming that the measurement of specific metal ion concentrations is the primary function of atomic absorption spectrometry.