Simultaneous assay of organic fluorine compounds in biological fluids by fluorine-19 nuclear magnetic resonance spectrometry over a large spectral width: Application to Fluoropyrimidines

¹⁹F-n.m.r. spectrometry is used as a direct method to assay simultaneously in body fluids (urine, plasma) all the fluorinated metabolites of a new antineoplastic drug fluoropyrimidine, 5′-deoxy-5-fluorouridine. The resonances of these metabolites are spread over a large spectral width (about 100 ppm). The calibration graphs for 5′-deoxy-5-fluorouridine and its major metabolite, α-fluoro-β-alanine, are linear over the range 10^?5–10^?1 M; the accuracy is 3–5% for urine samples and 5–7% for plasma samples. The method is applied to the determination of all the metabolites in urine from a patient.