UVabsorbance

UV absorbance refers to the ability of a substance to absorb ultraviolet (UV) radiation. Ultraviolet radiation is a portion of the electromagnetic spectrum with wavelengths shorter than visible light and longer than X-rays, typically ranging from 100 to 400 nanometers. Many molecules have the capacity to absorb UV light at specific wavelengths, a phenomenon that is highly dependent on the molecular structure.

When UV radiation interacts with a molecule, its energy can be absorbed, causing electrons within the molecule to transition from a lower energy state to a higher energy state. This absorption is a fundamental principle used in various analytical techniques, most notably UV-Vis spectroscopy. In UV-Vis spectroscopy, a sample is exposed to UV light, and the amount of light that is transmitted or absorbed at different wavelengths is measured. The resulting spectrum provides information about the concentration and identity of the substance.

The extent of UV absorbance is quantified by absorbance, which is a logarithmic scale. A higher absorbance value indicates that more UV light is being absorbed by the sample. This property is utilized in diverse fields, including chemistry for quantitative analysis of compounds, pharmaceuticals for quality control, environmental monitoring to detect pollutants, and in the development of sunscreens where UV-absorbing compounds are used to protect skin from harmful UV radiation.