Inductively coupled plasma optical emission spectrometry is an analytical technique used for the qualitative and quantitative analysis of chemical elements. It is a type of emission spectroscopy that uses an inductively coupled radio frequency plasma to produce excited atoms and ions that emit electromagnetic radiation at wavelengths characteristic of a particular element.

The samples, which have to be available in an aqueous solution, are introduced in the high temperature plasma where they are atomized, ionized and excited to emission. The intensity of the emissions from various wavelengths of light are proportional to the concentrations of the elements within the sample.

Since the samples have to be available in an aqueous solution a precondition for a comprehensive application of the ICP-OES is a chemical lab with powerful digestion methods like microwave-assisted digestion.