title: Synthesis of water-soluble phenylazosalicylaldehyde analogues and their application to capillary electrophoretic determination of primary amines.
abstract: Several primary amines are known to be endogenous substances, and they are to be detected at very low concentration level. Novel water-soluble azo dyes as precolumn derivatizing reagents were synthesized for the analysis of primary amines with strong visible-light absorption by CZE. A coupling reaction was used to introduce a sulfophenylazo group to salicylaldehyde or 1-hydroxy-2-naphthaldehyde to extend the conjugation and to improve the solubility in water of the derivatizing reagents, as well as the target compounds of the reaction products with the primary amines. Two azo dyes of 5-(4-sulfophenylazo)salicylaldehyde sodium salt (AZO1) and 4-(4-sulfophenylazo)-1-hydroxy-2-naphthaldehyde sodium salt (AZO2) were synthesized. Separation of eight kinds of n-alkylamines was performed by CZE after the derivatization with AZO1 or AZO2. The addition of Brij 35 to the running electrolyte and to the sample solutions was necessary to improve the solubility and the resolution among the analytes. Both reagents, AZO1 and AZO2, were compared with each other in terms of the reaction time of derivatization, the detection sensitivity and the total analysis time. The derivatization process using AZO2 was applied to the determination of four biogenic amines, histamine, tyramine, cadaverine and putrescine, and LODs at around micromolar level were achieved for the four amines.
authors.affiliation: The Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
authors.forename: Rim
authors.initials: R
authors.lastname: Driouich
authors.forename: Toshio
authors.initials: T
authors.lastname: Takayanagi
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Oshima
authors.forename: Shoji
authors.initials: S
authors.lastname: Motomizu
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis*; D000588:Amines / Q000032:analysis*; D001391:Azo Compounds / Q000138:chemical synthesis*; D001679:Biogenic Amines / Q000032:analysis; D019075:Electrophoresis, Capillary / Q000379:methods*; D007700:Kinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012995:Solubility; D014867:Water
chemical_list: D000447:Aldehydes; D000588:Amines; D001391:Azo Compounds; D001679:Biogenic Amines; D014867:Water; C013243:salicylaldehyde