GC/NCIMS法による尿および血漿中のフェニルピルビン酸の定量

概要

論文の詳細を見る
A method for the determination of phenylpyruvic acid (PPA) in human urine and plasma by gas chromatography/negative ion chemical ionization (NCI) mass spegtrometry was developed, in order to study its variation in concentration against time in the human body using an isotope labelled analogue. After 100 μl of urine and plasma sample spiked with [13C6]-PPA internal standard was purified with a hydrazide gel column, it was converted into the stable quinoxalinol derivative with 4,5-diamino-o-phenylendiamine in acidic solution, followed by conversion into the pentafluorobenzyl (PFB) derivative. The NCI mass spectra of the PPA-quinoxalinol-PFB derivative gave a base peak at m/z 263 (M-PFB)- with methane reagent gas. This ion was used for selected ion monitoring (SIM) in high resolution (R= 8,000) mode, with perfluorokerosene (PFK) used as a lock mass. The determination limit of this method was 1.0 pg. The PPA concentrations in urine and plasma from healthy persons were found to be 0.272±0.159 nmol/mg creatinine and 0.232±0.078 nmol/ml (n =12) with repeatability (R.S.D) of 3.3% and 4.2% (n = 5), respectively. The presence of keto- and enol-isomers in PPA-quinoxalinol derivatives were also confirmed from their IR spectra. The proposed method can be used for measuring the metabolism of PPA in vivo by labelled compound dosage.
日本質量分析学会の論文