Flame atomic absorption is a very common technique for detecting metals and metalloids in environmental samples. It is very reliable and simple to use. Figure 1 shows which elements are commonly detected through atomic absorption. The technique is based on the fact that ground state metals absorb light at specific wavelenths. Metal ions in a solution are converted to atomic state by means of a flame. Light of the appropriate wavelength is supplied and the amount of light absorbed can be measured against a standard curve.