HPLC with UV or Mass Spectrometric Detection for Quantifying Endogenous Uracil and Dihydrouracil in Human Plasma

Abstract

To estimate endogenous U and UH(2) concentrations and their ratio, we recommend the use of a drug-free human plasma pool in which baseline U and UH(2) concentrations have previously been measured with the standard-addition method. Our LC-MS method, which has the better test performance and is useful for measuring UH(2)/U ratios in cancer patients, is preferred when this equipment is available.