Rapid identification and quantitation of urinary metabolites of phenylalanine in phenylketonuria by gas chromatography

Joel M. Vavich, R. Rodney Howell

Research output: Contribution to journalArticle

13 Scopus citations


The major metabolites of phenylalanine present in phenylketonuric (PKU) urine, phenylpyruvic, phenyllactic, orthohydroxyphenylacetic, and phenylacetic acids, can be identified by gas chromatography as the trimethylsilyl derivatives, following pretreatment of the urine with hydroxylamine. Extraction from acidified urine with ethyl acetate and ether is followed by reaction with hexamethyldisilazane and chlorotrimethylsilane in pyridine. In addition, phenylacetylglutamine can be measured by the change in the phenylacetic level following acid hydrolysis. Quantitative data from 15 PKU patients are presented. Urinary patterns in PKU are distinct and easily distinguished from the normal.

Original languageEnglish (US)
Pages (from-to)159-167
Number of pages9
JournalThe Journal of Laboratory and Clinical Medicine
Issue number1
StatePublished - Jan 1971


ASJC Scopus subject areas

  • Pathology and Forensic Medicine

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