Spectrophotometric method is a method for qualitative and quantitative analysis of the substance by measuring the absorbance of the light at a certain wavelength or wavelength range. It has the advantages of high sensitivity, simple operation and fast, and is the most commonly used experimental method in biochemical experiments. Many substances are determined by spectrophotometry. In the spectrophotometer, the absorption intensity corresponding to different wavelength can be obtained when the light of different wavelengths is continuously irradiated to a certain concentration of sample solution.
The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, and molecular biology. They are widely used in many industries including semiconductors, laser and optical manufacturing, printing and forensic examination, as well in laboratories for the study of chemical substances. Spectrophotometry is often used in measurements of enzyme activities, determinations of protein concentrations, determinations of enzymatic kinetic constants, and measurements of ligand binding reactions. Ultimately, a spectrophotometer is able to determine, depending on the control or calibration, what substances are present in a target and exactly how much through calculations of observed wavelengths.