UV light is used in the UV-Excited or UVE photochemical derivatization process to stimulate a chemical reaction between a target molecule and a reagent. By using analytical methods like chromatography and mass spectrometry, a novel derivative molecule that is produced as a result of this reaction can be found. In particular, it is beneficial for the identification of chemicals that are challenging to identify using traditional techniques. For instance, some substances may be present in a sample in extremely small amounts or may be difficult to distinguish from other substances. In these circumstances, UVE photochemical derivatization can boost the analytical methods sensitivity and selectivity by making the target compound more detectable.