Optimization Of Amino Acid Derivatization Procedure Using Naphthalene-2,3-Dicarboxaldehyde For Capillary Electrophoresis With Fluorescence Detection

Amino acids (AAs) are very important compounds in living organisms and their quantification in biological fluids can be used for diagnostic purposes. For determination of AAs by capillary electrophoresis coupled with laser induced fluorescence detection (CE-LIF), derivatization procedure is necessary because only a few AAs exhibit native fluorescence. Derivatization reagent naphthalene-2,3-dicarboxaldehyde (NDA) reacts with prmary amines in the presence of nucleophile, such as cyanide anion, to form fluorescent derivates. Derivatization reaction can be done in pre-capillary or on-capillary arrangement. In on-capillary arrangement the capillary is used both for separation and derivatization. Optimization of pre-capillary and on-capillary derivatization procedure of AAs using NDA and NaCN, and comparison of these approaches were performed.