Concentrations of quinolinic acid in cerebrospinal fluid measured by gas chromatography and electron-impact ionisation mass spectrometry. Age-related changes in a paediatric reference population.
A simple method for the determination of the excitotoxin, quinolinic acid (QUIN) in cerebrospinal fluid (CSF) is described. QUIN, in lyophilized samples, was silylated by N-methyl-N-(tert.-butyldimethylsilyl)trifluoroacetamide in a single-step reaction at 65 to 70 degrees C to form a di-tert.-butyldimethylsilyl ester. Neither pre-purification of QUIN from CSF nor post-derivatisation sample clean-up was required. The derivatives were analysed by gas chromatography-electron impact mass spectrometry resulting in a prominent and characteristic [M-57]+ fragment ion which was used for quantitation. 2,6-Pyridine dicarboxylic acid, a structural analog of QUIN, was used as the internal standard. The detection limits for injected standards are in the femtomole range. CSF QUIN was found to be age-related and three preliminary reference ranges for CSF QUIN were found: 0 to 1 years, 31 +/- 15 nM QUIN (mean +/- standard deviation): 1.1 to 3 years, 26 +/- 15 nM; 3.1 to 14 years, 14 +/- 9 nM.
Dobbie
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MS
Division of Biochemistry and Genetics, Institute of Child Health (UCLMS), London, UK.
Surtees
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D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D017378:Quinolinic Acid / Q000134:cerebrospinal fluid* / Q000737:chemistry; D012015:Reference Standards; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D017378:Quinolinic Acid