Faure H, Incardona M F, Boujet C, Cadet J, Ducros V, Favier A
Laboratoire de Biochimie C, C.H.U., Grenoble, France.
J Chromatogr. 1993 Jun 23;616(1):1-7. doi: 10.1016/0378-4347(93)80465-g.
A method for the determination of 5-hydroxymethyluracil in urine is described. 5-Hydroxymethyluracil was extracted by reversed-phase chromatography and quantified by gas chromatography-mass spectrometry as tert.-butyldimethylsilyl derivative. Since natural 5-hydroxymethyluracil contained ca. 22% of M + 2 species, an internal standard consisting of [1,3-15N2,5-2H2]hydroxymethyluracil was used to correct losses during extraction, evaporation and derivatization. Between-run precision of this method was 7.79%, and concentrations as low as 1.87 nM could be measured. This sensitivity and precision could not be obtained with trimethylsilyl derivatives.