A non-enzymic procdure for the quantitative analysis of (3-methoxy-4-sulphoxyphenyl)ethylene glycol(MHPG sulphate) in human urine using stable isotope dilution and gas chromatography-mass spectrometry.

A method is described for the quantitative analysis of (3-methoxy-4-sulphoxyphenyl)-ethylene glycol (MHPG sulphate) in human urine, based on selected ion monitoring gas chromatography--mass spectrometry and using a specifically deuterium-labelled analogue of MHPG sulphate as internal standard. The procedure involves extraction of the urine sample on Amberlite XAD-2, followed by isolation of MHPG sulphate by column chromatography on Sephadex LH-20. Cleavage of the sulphate conjugate and formation of the MHPG tris(trifluoroacetate) derivative are carried out in a one-step reaction, without recourse to enzymic hydrolysis.