Spectrophotometry - optic method for research of gaseous, liquid and solid substances, based on the determination of the intensity of absorption of light by matter (absorption spectrophotometry) or radiation intensity of the light (emission spectrophotometry) depending on wavelength.
Obtained in this way (with the help of special instruments - spectrometers) absorption and emission spectra are characteristic for each of the given substance.
There are spectrophotometry in UV (UV), visible and infrared (IR) spectrum range.
Spectrophotometry is widely used in clinical, biochemical, sanitary-hygienic, forensic medical and pharmaceutical laboratories for qualitative and quantitative analysis of various biological objects (serum blood, cerebrospinal fluid, urine and other), medicines, food, etc.