Determination of salsolinol by ion-exchange chromatography with glycylglycine as the post-derivatizing agent.

The determination of salsolinol in human urine was carried out by ion-exchange chromatography on two coupled columns of a weakly acidic ion exchanger with a hydrophilic matrix (Asahipak ES-502C). Salsolinol was first isolated from urine by adsorption on Amberlite CG-50. It was eluted together with catecholamines by 2/3 M boric acid solution. The amines were then separated by isocratic elution from the first column of Asahipak with 0.05 M sodium succinate buffer (pH 5.5) containing 0.015 M borate and 0.5 mM ethylenediaminetetraacetate. Epinephrine, norepinephrine, dopamine and salsolinol were eluted in that order. The salsolinol-containing fraction was then transferred, by column switching, to a second Asahipak column and eluted with the same mobile phase. Salsolinol was determined fluorimetrically by reaction with glycylglycine in the presence of hexacyanoferrate(III) at pH 7.5-8 and 65 degrees C. Samples could be analysed every 47 min. The detection limit for salsolinol was 2 pmol/ml.