Iron as a model toxic-metal for green introductory chemistry: Dangerous enough to be interesting, safe enough to use

Liz Gron, Department of Chemistry, Hendrix College, 1600 Washington Ave., Conway, AR 72032

Power Point Presentation (PDF)

ABSTRACT: Using iron as a model toxic metal is an important method to engage introductory chemistry students in the study of metals in the environment. Students have a fundamental interest in environmental metal toxicity; however, it is unconscionable to use Hg, Pb and As in the laboratory at this level. We maintaining a green attitude by using iron while capturing student interest with the parallel to more dangerous materials. Molecular (UV-Vis) and atomic (FAA) spectroscopy are used on real and artificial environmental water samples. The procedures are modifications of standard protocols (EPA and AAOAC) that allow our introductory students to acquire accurate data in the available time. Students create calibration curves and use standard unknowns to check the precision and accuracy of their techniques. These laboratory experiments are supported with web exercises that discuss the toxic metals in the environment. In keeping with our green emphasis, the web portion of this project focuses Cr-As in landscaping timbers and the green replacement technology that won the 2002 Green Presidential Award. Protocols, student generated data, and assessment results will be presented.