Trace Analysis of Toxic Organic Substances in the Environment

Abstract

The use of incinerators to destroy municipal garbage and create useful energy is a practice of long standing. The fly ash produced by this process contains trace levels of organic compounds. Microanalytical methods for these compounds involve Soxhlet extraction with benzene, condensation of the extract by a factor of 2000 and analysis by GC and GC/MS techniques.

Over 200 compounds have been identified which include toxic compounds such as polycyclic aromatic hydrocarbons, polychlorinated dibenzo-dioxins (PCDD), polychlorinated aromatics and phenols and the polychlorinated dibenzofurans. Specific analysis by GC/MS with SIM technique for all isomers of the polychlorinated dibenzodioxins permits survey studies of variations of these compounds generated at a given municipal incinerator. Correlation studies indicate the PCDD compounds are not directly related to formation of other organic compounds. Particle size fractionation studies of a single fly ash sample show concentrations of PCDD isomeric groups and total organic compounds which vary significantly with particle size.