Measurement of plasma uracil using gas chromatography-mass spectrometry in normal individuals and in patients receiving inhibitors of dihydropyrimidine dehydrogenase

Daoqin Bi, Lawrence W. Anderson, Jeremy Shapiro, Alla Shapiro, Jean L. Grem, Chris H. Takimoto

Research output: Contribution to journalArticle

27 Scopus citations


A sensitive gas chromatographic-mass spectrometric method is described for reliably measuring endogenous uracil in 100 μl of human plasma. Validation of this assay over a wide concentration range, 0.025 ♂m to 250 ♂m (0.0028 μg/ml to 28 μg/ml), allowed for the determination of plasma uracil in patients treated with agents such as eniluracil, an inhibitor of the pyrimidine catabolic enzyme, dihydropyrimidine dehydrogenase. Calibration standards were prepared in human plasma using the stable isotope, [15N2]uracil, to avoid interference from endogenous uracil and 10 ♂m 5- chlorouracil was added as the internal standard.

Original languageEnglish (US)
Pages (from-to)249-258
Number of pages10
JournalJournal of Chromatography B: Biomedical Sciences and Applications
Issue number2
Publication statusPublished - Feb 11 2000



  • Dihydropyrimidine dehydrogenase
  • Eniluracil
  • Uracil

ASJC Scopus subject areas

  • Chemistry(all)

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