Analysis of sulfonated compounds by ion-exchange high-performance liquid chromatography–mass spectrometry

Ion-exchange high-performance liquid chromatography (HPIEC)–mass spectrometry (MS) was used for the analysis of different sulfonated compounds. HPIEC was performed on an aminopropyl column applying a gradient with increasing concentration of a buffer consisting of ammonium acetate–acetic acid and acetonitrile as the organic modifier. HPIEC is well suited to highly efficient separation of sulfonated compounds and furthermore, due to the volatility of ammonium acetate, the method is also appropriate for LC–MS coupling by the means of either atmospheric pressure chemical ionization or electrospray ionization. The applicability range of HPIEC–MS is demonstrated on the basis of a complex mixture of model substances consisting of sulfonated aromatics and textile dyes largely differing from each other in their structural properties.