Analysis of Dioxins, PCBs, PAHs, and nitro-PAHs in the Environment
Presenter: Dr. Joseph C. Pan
Manager, Dept. of Analytical and Environmental Chemistry, Southwest Research Institute
摘要：
Accumulation of toxic chemicals in our bodies is probably responsible for 50% of serious illness such as cancer in humans. There are hundreds, if not thousands, of chemicals (or pollutants) in the environment. These pollutants enter our bodies via the food we eat, the drinks we drink, and the air we breath. The environmental pollutants such as dioxins, PCBs, PAHs, and nitro-PAHs are among the most toxic compounds known to men.
PCBs were made years ago as dielectric fluid and used in the old transformers. Later, PCBs were found to be very toxic to animals (and possibly to humans as well). Although PCBs have been banned for new transformer use for more than 25 years, due to their high chemical stabilities, these compounds are still in the environment and need to be monitored. Dioxins, PAHs, and nitro-PAHs are byproducts of chemical manufacturing and combustion. They have no use in our daily lives. The municipal solid waste incinerator and medical waste incinerators generates substantial amounts of dioxins and PAHs. Other forms of combustion such as cigarette/cigar smoking and Bar-B-Queing also produce significant amounts of PAHs. Nitro-PAHs are mainly produced in diesel engine combustion. The nitro-PAHs formed are adsorbed on the particulates and released into the air in the black plume of smoke of diesel engine emission.
Due to their high toxicities, extremely low detection limits for these pollutants need to be achieved. Analyses of these pollutants involve sample extraction, sample extracts cleanup, GC/MS analysis, and data processing.
The formation of these highly toxic pollutant families, their toxic effects in mammals, and their analyses will be further discussed.
PCB = polychlorinated biphenyls. PAH = polycyclic aromatic hydrocarbons. GC/MS = gas chromatograph/mass spectrometer.