Atomic Absorption Spectrometry (AAS) is a technique for measuring quantities of chemical
elements present in environmental samples by measuring the absorbed radiation by the
chemical element of interest. This is done by reading the spectra produced when the sample
is excited by radiation. The atoms absorb ultraviolet or visible light and make transitions to
higher energy levels. Atomic absorption methods measure the amount of energy in the form
of photons of light that are absorbed by the sample.