Rapid analysis of GABA and glutamate in microdialysis samples using high performance liquid chromatography and tandem mass spectrometry

J Neurosci Methods. 2009 Aug 30;182(1):78-84. doi: 10.1016/j.jneumeth.2009.05.018. Epub 2009 Jun 6.

Abstract

A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method has been established for the rapid and reliable determination of gamma-aminobutyric acid (GABA) and glutamate in brain microdialysates. The microdialysis samples were analysed using a HILIC (hydrophilic interaction liquid chromatography) column, which is able to retain the polar amino acid neurotransmitters. The mobile phase consisted of a binary gradient elution profile comprising 0.1% formic acid in water and acetonitrile. GABA, glutamate as well as the respective internal standards [D(6)]-GABA and [D(5)]-glutamate were detected by a triple quadrupole mass spectrometer in the positive electrospray ionisation mode within a running time of 3 min. The linearity ranged from 1 nM to 10 microM for GABA and 10 nM to 10 microM for glutamate. The limit of quantitation was found to be 1 nM for GABA and 10nM for glutamate (injection volume 10 microl). The present LC-MS/MS method was compared to the classical method for analysis of GABA and glutamate using high performance liquid chromatography (HPLC) and fluorescence detection (FD). Eventually, the feasibility of the LC-MS/MS method was demonstrated using in vivo microdialysis in rats by monitoring changes of the extracellular concentrations of GABA and glutamate in the globus pallidus following stimulation with potassium.

Publication types

  • Evaluation Study

MeSH terms

  • Animals
  • Brain / metabolism*
  • Chromatography, High Pressure Liquid / methods*
  • Glutamic Acid / analysis*
  • Male
  • Mass Spectrometry / methods*
  • Microdialysis / methods*
  • Rats
  • Rats, Wistar
  • Reproducibility of Results
  • Sensitivity and Specificity
  • gamma-Aminobutyric Acid / analysis*

Substances

  • Glutamic Acid
  • gamma-Aminobutyric Acid