A stable isotope gas-liquid chromatographic-mass spectrometric assay for determining uric acid body pool size
✍ Scribed by R.W. Walker; W.J.A. VandenHeuvel; F.J. Wolf; R.M. Noll; D.E. Duggan
- Publisher
- Elsevier Science
- Year
- 1977
- Tongue
- English
- Weight
- 368 KB
- Volume
- 77
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
Studies have been carried out to develop a gas-liquid chromatographic-mass spectrometric assay for determining the uric acid body pool size in animals. A known quantity of [1 ,3-15N]uric acid is administered and the uric acid fraction is isolated from urine by a simple procedure involving ion exchange. The highly polar uric acid must be converted to a nonpolar, volatile derivative to permit successful gas chromatography. Both on-column methylation with trimethylanilinium hydroxide in methanol and trimethylsilylation with bis-trimethylsilyltrifluoroacetamide/pyridine were investigated; the latter approach was found preferable. Isotope intensity ratios for the molecular ions (m/e 456, 458) of the trimethylsilyl derivatives are obtained by mass fragmentography using an accelerating voltage alternator. As the monitored ions are intense, less than 20 ng of the isolated uric acid needs to be injected.