Analysis of Phenethylamines and Their Metabolites by Column-switching Liquid Chromatography/Mass Spectrometry

Abstract

  Liquid chromatography (LC) with a column-switching system connected to electrospray ionization mass spectrometry (ESI-MS) was developed for the determination of phenethylamines and their metabolites in urinary and serum samples. After filteration, the sample was directly injected, and drugs were concentrated onto a strong cation-exchange (SCX) precolumn with an eluate of 10 mM ammonium acetate (pH 5). After 5 min elution, a six-port valve was switched, and drugs were introduced to a reversed-phase analytical column with an elution by 10 mM ammonium acetate (pH 5)-acetonitrile (80:20). Analytes eluted were introduced directly into the ESI source connected to an ion-trap detector. Linearity of quantification was obtained over the concentration range of 50-500 ng/ml for 2C-B and 20-500 ng/ml for the other compounds. The detection limit of each compound in urine samples ranged 5-50 ng/ml under scan mode. This method appeared rapid and sensitive for the determination of phenethylamines and their metabolites in biological samples.