CE with sequential light-emitting diode-induced fluorescence and electro-chemiluminescence detections for the determination of amino acids and alkaloids

Electrophoresis. 2007 Apr;28(7):1092-9. doi: 10.1002/elps.200600546.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alkaloids / analysis*
  • Alkaloids / chemistry
  • Alkaloids / urine
  • Amino Acids / analysis*
  • Amino Acids / chemistry
  • Amino Acids / urine
  • Electrophoresis, Capillary / methods
  • Fluorescence
  • Fluorescent Dyes / chemistry
  • Humans
  • Luminescent Measurements
  • Male
  • Naphthalenes / chemistry
  • Nicotiana / chemistry
  • Organometallic Compounds / chemistry
  • Plant Extracts / chemistry
  • Polyethylene Glycols / chemistry

Substances

  • Alkaloids
  • Amino Acids
  • Fluorescent Dyes
  • Naphthalenes
  • Organometallic Compounds
  • Plant Extracts
  • tris(2,2'-bipyridyl)ruthenium(II)
  • Polyethylene Glycols
  • 2,3-naphthalenedicarboxaldehyde