title: CE with sequential light-emitting diode-induced fluorescence and electro-chemiluminescence detections for the determination of amino acids and alkaloids.
abstract: This paper describes the determination of alkaloids and amino acids (AAs) using CE in conjunction with sequential light-emitting diode-induced fluorescence (LEDIF) and electrochemiluminescence (ECL) detections. In the CE-LEDIF-ECL system, the ECL detector was located in the outlet of the capillary, while the LEDIF detector was positioned 12 cm from the outlet. Naphthalene-2,3-dicarboxaldehyde (NDA) was used to form fluorescent AA-NDA derivatives from AAs possessing primary amino groups, while Ru(bpy)(3) (2+) was used to obtain ECL signals for analytes having secondary and tertiary amino groups. In the presence of poly(ethylene oxide), we accomplished the CE-LEDIF-ECL separation of a mixture of 12 AA-NDA derivatives, anabasine, nicotine, and proline within 11 min. This low-cost CE-LEDIF-ECL system allows the analysis of these AA-NDA derivatives and alkaloids at concentrations in the ranges of 49 nM-0.2 microM and 0.66-4.7 microM, respectively. We applied our CE-LEDIF-ECL system to the analysis of a urine sample and also to tobacco extracts. We obtained good qualitative and quantitative results when using this method with these analytes: the RSDs were below 3.0 and 2.8%, respectively. This CE-LEDIF-ECL system provides the advantages of high efficiency, speed, and sensitivity for the analysis of analytes possessing amino groups.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei, Taiwan.
authors.forename: Po-Ling
authors.initials: PL
authors.lastname: Chang
authors.forename: Kun-Hong
authors.initials: KH
authors.lastname: Lee
authors.forename: Cho-Chun
authors.initials: CC
authors.lastname: Hu
authors.forename: Huan-Tsung
authors.initials: HT
authors.lastname: Chang
mesh_terms: D000328:Adult; D000470:Alkaloids / Q000032:analysis* / Q000737:chemistry / Q000652:urine; D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry / Q000652:urine; D019075:Electrophoresis, Capillary / Q000379:methods; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D009281:Naphthalenes / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D014026:Nicotiana / Q000737:chemistry
chemical_list: D000470:Alkaloids; D000596:Amino Acids; D005456:Fluorescent Dyes; D009281:Naphthalenes; D009942:Organometallic Compounds; D010936:Plant Extracts; C415768:tris(2,2'-bipyridyl)ruthenium(II); D011092:Polyethylene Glycols; C027717:2,3-naphthalenedicarboxaldehyde