<P> A new preconcentration method had been developed for
the determination of some trace-metal ions in lakewater.
This method is based on the formation of their TPPS4 complexes
at elevated temperatures in solution and adsorption of
the complexes onto a column of the macroporous acrylic ester
resin, XAD-7. The complexes are eluted with a methanolic
solution and the metal concentration determined by graphitefurnace
atomic absorption spectroscopy. Optimal conditions
were established for the group preconcentration of Cd, Cu, Ni
and Pb. The concentration of these trace metals in several
lakewater samples were determined successfully, with a
precision comparable to that of the accepted Chelex-100
method. Application of the method to natural seawater
samples failed, largely because of aggregation in the highly
saline medium. </p> <P> Adsorption isotherms of TPPS4 and its complexes on
XAD resins were obtained. Adsorption onto XAD-2 and XAD-4
resins likely involves n-n interactions while adsorption onto
XAD-7 is probably due to weak Van der Waals forces. The
adsorption at high TPPS4 concentrations is complicated by
aggregation. </p> <P> An attempt to create a simple chelating ion-exchange resin by adsorption of TPPS4 onto XAD resin failed. Similarly,
the development of a rapid room-temperature preconcentration
method specifically for Pb and Cd in natural waters was
not successful. </p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19204 |
| Date | 01 1900 |
| Creators | Zweep, Carol |
| Contributors | Corsini, A., Chemistry |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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