The general term nebulizer refers to an apparatus that converts liquids into a fine mist. Nozzles also convert liquids into a fine mist, but do so by pressure through small holes. Nebulizers generally use gas flows to deliver the mist. The most common form of nebulizers are medical appliances such as asthma inhalers or paint spray cans. Analytical nebulizers are a special category in that their purpose is to deliver a fine mist to spectrometric instruments for elemental analysis. They are necessary parts of inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), and atomic absorption spectroscopy (AAS).

Atomic absorption spectroscopy (AAS) and atomic emission spectroscopy (AES) is a spectroanalytical procedure for the quantitative determination of chemical elements by free atoms in the gaseous state. Atomic absorption spectroscopy is based on absorption of light by free metallic ions.