Determination of 3-methoxy-4-hydroxyphenylpyruvic acid, 3,4- dihydroxyphenylethylene glycol, and 3,4-dihydroxyphenylmandelic acid in urine by mass fragmentography, with use of deuterium-labeled internal standards

Abstract

The authors report the determination of 3-methoxy-4-hydroxyphenylpyruvic phenylpyruvic acid, 3,4-dihydroxyphenylmandelic acid, and 3,4-dihydroxyphenylethylene glycol in urine, by use of gas chromatography/mass spectrometry in combination with a simple purification method and deuterium-labeled internal standards. Normal excretion values in terms of creatinine, expressed as a function of age, are given, together with results obtained for patients with neuroblastoma, pheochromocytoma, or parkinsonism treated with L-DOPA + peripheral decarboxylase inhibitor, and for a patient receiving dopamine. The authors were unable to identify 3,4-dihydroxyphenylpyruvic acid and 3,4-dihydroxyphenyllactic acid in urine. The results obtained and their relation to other catecholamine metabolites and catecholamine-precursor metabolites in urine are discussed.