Glossary

Widely used physical-chemical analytical method for detecting and determining the concentration of organic and inorganic substances. Measures the absorbed wavelength and the intensity of the absorption.

Absorption spectrum of a solution of Fe3+ in hydrochloric acid (concentration 50 ppm, path length 2 mm)

Plotting of the absorption spectrum (absorbance as a function of the wavelength) makes it possible to pinpoint the wavelength at which the respective substance absorbs the light energy. The intensity of the absorption is used for calculating the concentration of the substance according to the Lambert-Beer Law.

Spectrum