title: Development of a protocol for the automated analysis of amino acids in brain tissue samples and microdialysates.
abstract: An automated precolumn derivatisation method has been developed for the measurement of fourteen amino acids in brain tissue and microdialysate samples. The method involves labelling amino acids with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide (CN-). The resulting highly stable N-substituted 1-cyanobenz[f]isoindole (CBI) derivatives were separated using a binary gradient elution profile and detected fluorometrically. The order of elution of the derivatised amino acids was confirmed by using liquid chromatography with fluorescence and mass spectrometric detection in tandem. Linear calibration plots were obtained for all amino acids in the range studied (0.2-12.5 microM). The limit of detection for CBI derivatives of amino acids was in the range 5-20 fmol (S/N=2) using a 5 microl injection volume. The method has been used for the measurement of amino acids in microdialysates from rat brain and tissue homogenates from different regions of mouse brain.
authors.affiliation: SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Harlow, Essex, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Shah
authors.forename: V
authors.initials: V
authors.lastname: de Biasi
authors.forename: S G
authors.initials: SG
authors.lastname: Taylor
authors.forename: C
authors.initials: C
authors.lastname: Roberts
authors.forename: P
authors.initials: P
authors.lastname: Hemmati
authors.forename: R
authors.initials: R
authors.lastname: Munton
authors.forename: A
authors.initials: A
authors.lastname: West
authors.forename: C
authors.initials: C
authors.lastname: Routledge
authors.forename: P
authors.initials: P
authors.lastname: Camilleri
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D000818:Animals; D001331:Automation; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D017551:Microdialysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000596:Amino Acids