The analysis of urinary meta- and para-tyramine by gas chromatography with electron-capture detection.

A simple, reliable method for the analysis of urinary meta- and para-tyramine has been developed. Sample purification was achieved by a weak anion-exchange column, followed by extraction into ethyl acetate at pH 10.2. The heptafluorobutyryl derivative was measured by packed column gas chromatography with electron-capture detection, using para-hydroxyphenylpropylamine as internal standard. The results agreed well with those obtained by gas chromatography-mass spectrometry. The daily output of unconjugated and conjugated meta- and para-tyramine by 23 adults was measured. In consecutive 24 h urine samples from a single subject there was little day-to-day variation in the level of excretion of unconjugated meta- and para-tyramine, whereas the conjugated amines exhibited marked fluctuations.