Dabsyl chloride is an amine derivatizing agent, able to give rise to stable products that can be easily monitored spectrophotometrically at 460 nm; Dabsyl chloride also used for labeling amino acids.
Dabsyl chloride can give rise to mono-Dabsyl and bis-Dabsyl derivatives in the presence of multiple amino groups. Furthermore with respect to OPA derivatization, Dabsyl chloride can react with primary and also with secondary amines.
. Francioso A, et al. HPLC Determination of Bioactive Sulfur Compounds, Amino Acids and Biogenic Amines in Biological Specimens. Adv Exp Med Biol. 2017;975:535-549.