Used primarily as a derivatizing agent in analytical chemistry to detect and quantify compounds containing hydroxyl or amino groups, especially in steroids, neurotransmitters, and bile acids. Its sulfonyl chloride group reacts readily to form stable sulfonate esters or sulfonamides, which are more easily detected by techniques such as fluorescence spectroscopy, HPLC, or mass spectrometry. Also employed in the synthesis of sulfonamide-based pharmaceuticals and as an intermediate in the preparation of fluorescent probes due to its ability to enhance detection sensitivity. Commonly used in research settings for labeling biomolecules prior to analysis.