Principle : The ultraviolet-visible spectroscopy is a technique of spectroscopy involving photons whose wavelengths are in the field of ultraviolet (100 nm – 400 nm), visible (400 nm – 750 nm) or near infrared (750 nm – 1400 nm). the photons from the radiation transfer in the compounds analyzed an energy that excites the molecules, atoms or ions through which they pass. a portion of the incident radiation is absorbed. the study of the radiation after passage through the substance analyzed to obtain information about its nature.
the electronic spectrum is the function that links the intensity of light absorbed by the sample analyzed as a function of the wavelength. the spectrum is usually presented as a function of the absorbance as a function of the wavelength. it can also be presented as the coefficient of molar extinction as a function of the wavelength.