Depending on the elements to be determined, elemental analysis or optical emission spectrometry (OES) is the method of choice if a highly precise and fast metal analysis of the elemental concentrations is required. Atomic spectroscopy instruments can be divided into three basic types, depending on whether the phenomenon measured is based on light absorption, emission or fluorescence. Flame atomic absorption spectrometry also can be used, but iron solutions are notorious for clogging the burner with iron oxide when the. 5. The principle of AAS relies on the vaporization of metals within a sample when introduced to a flame. Every ground state metal absorbs light radiation (and. Spectroscopy is a common method for analyzing metal composition due to its high precision and ability to detect a wide range of elements. It's highly sensitive and can detect very low concentrations of trace.