“Optimization of a Colorimetric Bioassay”

Prof. Coates is in the Department of Plant and Microbial Biology in the College of Natural Resources, UC Berkeley

A method for the extraction and concentration of perchlorate from solution using styrene divinyl benzene resin treated with decyltrimethylammonium (DTAB) was formulated for the purpose of optimizing a colorimetric bioassay. This bioassay was constructed to detect perchlorate concentration levels comparable to those that can be obtained with ion chromatography, which the Environmental Protection Agency uses today. Several simplistic methods using tea bags to enclose the resin were performed and analyzed for their ability to extract perchlorate from solution. Of all the methods tested, the best extraction of perchlorate resulted from the placement of the resin packets in beakers with solution on a hot plate using the magnetic stirrer. Using this method extracted about fourty to fifty percent of perchlorate in the solution. This refined process in combination with the continuing steps of the bioassay, can lower the cost, time, equipment, and specialized personnel needed to identify concentrations of perchlorate in water samples.

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Hannah is currently a student at Chabot community college. She plans on transferring to UC Berkeley to major in Chemistry. After her undergraduate studies, she intends to pursue PhD in Chemistry. She is particularly interested in learning how she can utilize chemistry in ways to help the environment.