Atomic Absorption Spectroscopy, Atomic Emission Spectroscopy, and Inductively Coupled Plasma Mass Spectrometry

Atomic absorption spectroscopy (AAS) quantifies the absorption of electromagnetic radiation by well-separated neutral atoms, while atomic emission spectroscopy (AES) quantifies the emission of radiation from well-separated neutral atoms in the excited states. AAS and AES accurately measure individual elements even in the presence of other food components because atomic absorption and emission spectra are unique for each element. The development of inductively coupled plasma (ICP) as an excitation energy source has allowed spectroscopic analysis of multiple elements in a single sample. When combined with mass spectrometry (MS), ICP-MS is a powerful tool for measuring ultra-trace minerals as well as isotopes of the same element. Technological advances over the past seven decades have had a major impact on food mineral analysis. Today, rapid measurements of a large number of mineral nutrients and non-nutrients in foods can be made with excellent precision using commercially available instruments. This chapter covers the principles of operation and instrumentation for AAS, AES, and ICP-MS, and the comparative advantages and disadvantages of these methods.