Characterization of the high molecular mass chlorinated matter in spent bleach liquors (SBL): 3—Mass spectrometric interpretation of aromatic degradation products in SBL

Abstract

The aromatic content of the high molecular matter in pulp mill bleachery e5uents has been characterized after chemical degradation in the laboratory followed by derivatization and gas chromatographic/mass spectrometric analysis. Aromatic molecules with carboxy, hydroxy, methoxy and chloro substituents were separated and identified by recording their computer-reconstructed ion current chromatograms. About 70 aromatic carboxylic acids were tentatively identified as degradation products. Aromatic compounds with hydroxy groups were derivatized to trideuteromethoxy groups in order to distinguish them by mass spectrometry from compounds with naturally occurring methoxy groups. Sigle and double hydrogen atom transfer between methyl ester and methoxy groups were observed in some molecules and given special attention when they occurred ortho to each other. A methoxy group substituted ortho to a methyl carboxylate resulted in an unusual fragmentation.

The use of fast molecular descriptors and artificial neural networks approach in organochlorine compounds electron ionization mass spectra classification

“…In case of majority organochlorine compounds, two characteristic MS peaks can be distinguished, namely, molecular ion peak [M] and [M-35] signal which is related to the most abundant chlorine isotope 35 Cl elimination (Krupčík et al 1976;Österberg and Lindström 1985;Webster and Birkholz 1985;Nolte et al 1993;Beil et al 1997;Pollmann et al 2001). When [M] is not the base peak, fragmentation proceeds rapidly.…”