Ultraviolet-visible spectroscopy (UV-Vis), an absorbance-based analytical technique, measures and identifies chemicals that absorb in the contiguous ultraviolet and visible regions of the electromagnetic spectrum.

Fourier transform infrared (FTIR) spectroscopy, a subset of infrared (IR) spectroscopy, uses a mathematical algorithm, Fourier transform, to translate raw infrared data into a spectrum.

Raman spectroscopy is based on the interaction of visible, near-infrared, or near-ultraviolet light on chemical bonds. When excited with light energy, bonds experience short-lived, higher-energy vibrational states.

Atomic absorption (AA) has been known since the 19th century, but it was not until the 1950s, thanks to efforts by Alan Walsh at Australias CSIRO research center, that use of AA spectrometers became routine for metals analysis.

The need to verify that an instrument is performing properly and is in calibration is becoming increasingly common for regulatory committees and internal QC procedures.