Determination of epichlorohydrin by sulfite derivatization and ion chromatography: characterization of the sulfite derivatives by ion chromatography–mass spectrometry

This work is an upgrade of a previously developed method [J. Chromatogr. A 884 (2000) 251] for epichlorohydrin determination by ion chromatography (IC) and conductivity detection. Here, an ion chromatography–mass spectrometry (IC–MS) coupling has been employed for the separation and the identification of products of epichlorohydrin when reacted with the nucleophilic agent SO32−. The high capacity column (IonPac AS11-HC) used for separation provided good resolution. This allowed evaluation of the IC behavior and mass spectrometric identification of epichlorohydrin sulfite derivatives. By using atmospheric pressure interfaces (ESI and APCI) the following species were tentatively identified: 2,3-dihydroxy-1-propanesulfonic, 2,3-epoxy-1-propanesulfonic, 1,3-dihydroxy-2-propanesulfonic and 3-oxetanesulfonic acids and 2-hydroxy-1,3-propanedisulfonic acid (or its isomer 3-hydroxy-1,2-propanedisulfonic acid). The study showed that chlorine atoms are displaced from epichlorohydrin during the reaction, while mass spectrometry confirmed that none of the products formed contains chlorine atoms.