http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
innovative approach to the detection of water-solvated chlorophenols and the subsequent dechlorination of water-solvated pentachlorophenol
in most aquatic environments. Direct consumption and
bioaccumulation from potable water are two pathways that can
expose humans to these toidns which have been labeled as both
systemic toxins and as potential carcinogens. Their toxicity
and lipophilicity are a result of their degree of
chlorination; thus dechlorination leads to detoxification.
Current detection of these compounds is based on complicated
instrumentation that is both expensive and requires technical
expertise. Detoxification has been accomplished using
certain biological organisms and chemical techniques. There
is a need for a simple field-practical assay for water
solvated chlorophenols that offers both sensitivity and
selectivity. If water-solvated chlorophenols are detected,
there is the need to dechlorinate, and thus detoxification,
the more toxic chlorophenols, especially pentachlorophenol. A
simple, field-practical assay for water-solvated
chlorophenols based on fluorescent derivatization was
developed. The water-solvated chlorophenols were derivatized
and the derivatized complex was extracted from other
impurities found in potable water. The fluorescent complex
was bound on a reactive interface housed in a glass
minicolumn and fluorescence was induced by ultraviolet
radiation. This assay offered great sensitivity (O. Igg)
and selectivity. All detection error was positive error
which would minimize exposure to an unknown risk.
Dechlorination of water-solvated pentachlorophenol was
accomplished using three morphologically different ammonium-
exchanged calcium montmorillonites. Ammonium-exchanged
Nevalite montmorillonite (AENM) demonstrated the ability to
dechlorinate water-solvated pentachlorophenol by 23% in 60
hours. A second, better-characterized exchanged calcium
montmorinonite, ammonium-exchanged calcium montmorillonite
(AECM) demonstrated similar ability to dechlorinate
pentachlorophenol in aqueous solution by 18.2% in 60 hours.
Calcium montmorillonite was then propped with hydroxy
aluminum, greatly increasing the interlaminar area.
Ammonium-exchange of this propped clay greatly increased its
dechlorination ability to 26.6%. Hydra attenuate, small
fresh-water coelenterates which are sensitive to halogenated
compounds such as pentachlorophenol, were used as a bioassay
to evaluate if absorption and dechlorination of
pentachlorophenol resulted in decreased toxicity. This
bioassay demonstrated that two of the three clays were able
to afford protection. in potable water. The fluorescent
complex was bound on a reactive interface housed in a glass
radiation. This assay offered great sensitivity (O. ltlg)
Issued also on microfiche from University Microfilms Inc.
Includes bibliographical references: pages 149-162.