Chromatographia

, Volume 68, Supplement 1, pp 57–62

Measurement of Hydroxyl-Radical Formation in the Rat Striatum by In Vivo Microdialysis and GC-MS

Authors

  • Vien Nguyen
    • Department of Molecular Biology and ImmunologyUniversity of North Texas Health Science Center
  • Darius V. Bonds
    • Department of Molecular Biology and ImmunologyUniversity of North Texas Health Science Center
    • Department of Molecular Biology and ImmunologyUniversity of North Texas Health Science Center
Original

DOI: 10.1365/s10337-008-0703-6

Cite this article as:
Nguyen, V., Bonds, D.V. & Prokai, L. Chroma (2008) 68: 57. doi:10.1365/s10337-008-0703-6

Abstract

A GC-MS method was developed for measuring hydroxyl-radical capture products of salicylic acid, a common trapping agent for this reactive oxygen species, in samples obtained by in vivo cerebral microdialysis experiments. The assay employed liquid–liquid extraction followed by derivatization of 2,3- and 2,5-dihydroxybenzoic acid, along with 3,5-dihydroxybenzoic acid added as an internal standard. Due to their simple electron ionization mass spectra featuring [M–57]+ ions through the loss of tertiary alkyl group from the corresponding molecular ions, tert-butyldimethylsilyl (TBDMS) derivatives afforded straightforward method development based on selected-ion monitoring. In addition, tandem mass spectrometry probing collision-induced dissociation of [M–57]+ ions obtained from the isomeric tert-butyldimethylsilyl derivatives revealed characteristic differences in the resultant product-ion spectra. Our work has demonstrated the applicability of GC-MS for the assay of microdialysates for 2,3- and 2,5-dihydroxybenzoic acid by confirming that local administration of the excitotoxic glutamate into the rat striatum significantly increased in vivo hydroxyl-radical production in this brain region and that subsequent systemic administration of α-phenyl-tert-butylnitrone reversed glutamate-induced oxidative stress.

Keywords

Gas chromatography-mass spectrometry In vivo intracranial microdialysis Derivatization Oxidative stress Dihydroxybenzoic acid

Copyright information

© Vieweg+Teubner | GWV Fachverlage GmbH 2008