UV Spectrophotometry

Analyzing light absorption

UltraViolet/Visible Spectrophotometry (UV/Vis) is defined by PDA TR29 to "involve measuring transmission/absorbance of a specified wavelength of light by a solvent solution of the residue."
The FDA's Biotechnology Inspection Guide defines UV Spectrophotometry as "a quantitation technique for proteins using their distinctive absorptionn spectra due to the presence of side- chain chromophoes." UV/Vis is often used in small molecule, specifically API, manufacturing since it is not necessary to separate from the matrix to quantify the residue and is considered. UV/Vis is acceptable to use throughout the entire cleaning validation lifecycle (design/development, qualification, and maintenance) and can be used for investigations.