Determination of free salsolinol concentrations in human urine using gas chromatography-mass spectrometry.

The urine concentrations of free salsolinol were determined in six healthy volunteers, using a gas chromatographic-mass spectrometric method with electron-capture negative-ion chemical ionization after derivatization with pentafluoropropionyl anhydride. The sensitivity of this method allows the quantification of salsolinol concentrations of 0.55 pmol/ml. The synthesis of [2H4]salsolinol from dopamine and [2H4]acetaldehyde via a Pictet-Spengler condensation is described; [2H4]salsolinol was used as the internal standard for salsolinol quantification. The urine concentrations of free salsolinol ranged from ca. 1 to 6 pmol/ml.