Microchip capillary electrophoresis with amperometric detection for rapid separation and detection of seleno amino acids

J Chromatogr A. 2005 Oct 14;1091(1-2):177-82. doi: 10.1016/j.chroma.2005.07.055.

Abstract

This article describes an effective microchip capillary-electrophoresis protocol for rapid and effective measurements of food-related seleno amino acids, including Se-methionine (Se-Met), Se-ethionine (Se-Eth), Se-methyl cysteine (Se-Cys), utilizing o-phtaldialdeyde/2-mercaptoethanol (OPA/2-ME) derivatization. Relevant parameters of the chip separation and amperometric detection are examined and optimized using a response surface methodology (RSM). Under optimum conditions, the analytes could be separated and detected in a 30 mM borate buffer (pH 9.3, with 28 mM sodium dodecul sulfate) within 300 s using a separation voltage of 2000V and a detection voltage of +0.9 V. Linear calibration plots are observed for micromolar concentrations of the Se-amino acid compounds. The negligible sample volumes used in the microchip procedure obviates surface fouling common to amperometric measurements of selenoamino-acid compounds. The new microchip protocol offers great promise for a wide range of food applications requiring fast measurements and negligible sample consumption.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acids / analysis*
  • Amino Acids / chemistry
  • Amino Acids / isolation & purification*
  • Electrophoresis, Microchip / methods*
  • Flow Injection Analysis
  • Hydrogen-Ion Concentration
  • Mercaptoethanol
  • Sodium Dodecyl Sulfate
  • Time Factors

Substances

  • Amino Acids
  • Sodium Dodecyl Sulfate
  • Mercaptoethanol