PT  - JOURNAL ARTICLE
AU  - C E Hignite
AU  - C Tschanz
AU  - D H Huffman
AU  - D L Azarnoff
TI  - Quantitation of N-demethylantipyrine in biological samples and isolation and characterization of its glucuronic acid conjugate.
DP  - 1978 May 01
TA  - Drug Metabolism and Disposition
PG  - 288--295
VI  - 6
IP  - 3
4099  - http://dmd.aspetjournals.org/content/6/3/288.short
4100  - http://dmd.aspetjournals.org/content/6/3/288.full
SO  - Drug Metab Dispos1978 May 01; 6
AB  - An improved method for quantitating N-demethylantipyrine (N-DEM-AP) in urine by gas chromatography or gas chromatography-mass spectrometry has been developed. Recovery of greater than 90% of N-DEM-AP was achieved by extraction of the sample at pH 1 after addition of 3-amino-1-phenyl-2-pyrazolin-5-one. The coefficient of variation of replicate analyses was 8%. N-DEM-AP was excreted in the urine as a glucuronic acid conjugate. This conjugate was isolated from the urine of an individual receiving antipyrine and purified. The NMR and mass-spectral data are consistent with the conjugate being an O-glucuronide of N-DEM-AP in its enol form.