A UV–Vis spectrophotometer is an analytical instrument that measures the amount of ultraviolet (UV) and visible light that is absorbed by a sample. It is a widely used technique in chemistry, biochemistry, and other fields, to identify and quantify compounds in a variety of. Ultraviolet–visible spectrophotometry (UV–Vis or UV-VIS) refers to absorption spectroscopy or reflectance spectroscopy in part of the ultraviolet and the full, adjacent visible regions of the electromagnetic spectrum. Electron transition takes place, so it is also called electron spectroscopy. Its popularity comes from its versatility, simplicity, and broad applicability, as it can detect nearly every molecule under the right conditions. Since every molecule absorbs a unique pattern of wavelengths, this.