title: Impact of halides on the simultaneous separation of aromatic amines and their acidic metabolites by capillary electrophoresis with laser-induced native fluorescence detection under acidic conditions.
abstract: This paper describes a simple, sensitive, efficient, and rapid method for simultaneous analysis of biologically active amines and acids by capillary electrophoresis in conjunction with laser-induced native fluorescence detection (CE-LINF) using a diode pumped solid state nanolaser at 266 nm. In order to optimize resolution of the amines that were prepared in 10.0 mM formate-Tris (FT) solutions, 10.0 mM FT solutions with and without containing halides were used to fill the capillary and reservoirs, respectively. The electrophoretic mobilities of tryptamine (TA) and serotonin (5-HT) at pH 4.0 decrease with the increase in halide concentration (0-10.0 mM). Taken together with a great effect of iodide than other halides, we suggest that the formation of ion pairs is a main contributor for altering the migration of the amines. In order to simultaneously analyze the amines and their metabolites (acids) at low pH, a high bulk EOF is required. The analysis of 10 anlytes including amines and acids was completed within 12 min by CE-LINF using a capillary treated with 0.5M NaOH and then filled with 10.0 mM FT solutions (pH 4.0) containing 10.0 mM KCl prior to analysis. The limits of detection for TA and 5-hydroxyindole-3-acetic acid (5-HIAA) are 0.12 and 6.0 nM, respectively. The present method has been further validated by analyzing urine samples, with an RSD less than 3.1% (migration times) and 3.9% (concentration).
authors.affiliation: Department of Applied Chemistry, Fooyin University, 151 Chin-Hsueh Road, Ta-Liao Hsiang, 831 Kaohsiung Hsien, Taiwan. sc126@mail.fy.edu.tw
authors.forename: Ming-Mu
authors.initials: MM
authors.lastname: Hsieh
authors.forename: Huan-Tsung
authors.initials: HT
authors.lastname: Chang
mesh_terms: D000143:Acids; D000588:Amines / Q000302:isolation & purification* / Q000652:urine; D019075:Electrophoresis, Capillary / Q000379:methods*; D006219:Halogens / Q000737:chemistry*; D006801:Humans; D007834:Lasers; D008297:Male; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D000143:Acids; D000588:Amines; D006219:Halogens