PYROLYSIS-GC AED AND PYROLYSIS-GC/MS ANALYSIS OF CHLORINATED STRUCTURES IN AQUATIC FULVIC-ACIDS AND CHLOROLIGNINS/

A study was undertaken to evaluate whether pyrolysis-gas chromatograph y/atomic emission detection (Py-GC/AED) and pyrolysis-gas chromatograp hy/mass spectrometry (Py-GC/MS) can be used to systematically search f or halogenated structures in natural organic matter. Two samples of aq uatic fulvic acid (FA) and two samples of high molecular weight organi c matter isolated from bleached-kraft mill effluents (BKME) were selec ted to respectively represent naturally and industrially chlorinated o rganic matter. Mono- and dichlorophenol were found in the pyrolysates of the naturally chlorinated samples, and methyl esters of 2,4-dichlor obenzoic acid, monochloro-4-methoxybenzoic acid and 3,5-dichloro-4-met hoxybenzoic acid were the main compounds detected when a methylating a gent, tetramethylammonium hydroxide (TMHA), was added to the samples p rior to the pyrolysis. These results strongly indicate the presence of chlorinated 4-hydroxyphenyl structures in the original FA samples. Fo r the BKME samples, on the other hand, the main chlorinated pyrolysis products were guaiacyl- and syringyl-derived compounds. (C) 1997 Elsev ier Science Ltd.