Advances in Liquid Chromatographic and Voltammetric Analysis of Underivatized Amino Acids

A.      Pappa-Louisi; P.      Agrafiotou; S.      Sotiropoulos

doi:10.2174/138527210793351535

Abstract

The problems associated with liquid chromatographic analysis of underivatized amino acids are identified and, through reviewing the recent ten years literature, possible solutions are described. Emphasis has been placed on amperometric as well as on multi mode detection. The advantages offered by preliminary voltammetric studies at microelectrodes (under mass transfer conditions similar to those of a flow cell detector) in optimising the operation of amperometric detectors are discussed and the use of environmentally friendly Bi electrode materials for the stripping voltammetric determination of amino acids is also proposed. This review is also aimed at giving a broad outline of the potential for improvement of the separation of underivatized amino acids offered by multimode gradient elution and/or ion-chromatography provided that the relevant separation theory and optimization algorithms are available.

Keywords: Underivatized amino acids, liquid chromatographic separation, ultraviolet, conductivity, evaporative light scattering, mass spectrometry, electrochemical, voltammetric analysis, Conductometric detection, capacitively coupled contactless conduc-tivity detection, C4D, RI, refractive index detector, ELS, ELS detector, Chemiluminescent nitrogen, CLN, CLN detector, Fluorescence (FL) Detection, nuclear magnetic resonance, NMR, Electrochemical (EC) or Amperometric Detection, homocystinuria, sinusoidal voltammetry, SV, Linear Sweep, Differential Pulse Voltammetry, LSV, DPV, Adsorptive Stripping Voltammetry, CSV, AdSV, cathodic stripping voltammetry, square wave cathodic stripping voltammetry, SWCSV, Carbon Paste Electrodes, CPEs, Reversed-phase liquid chromatography, RP-HPLC, reversed phase ion-pair chromatography, IPC, drophilic interaction chromatography, HILIC