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Date of Award

4-2009

Document Type

Restricted Thesis: Campus only access

Degree Name

Bachelor of Science

Department

Chemistry

First Advisor

Dr. Christopher L. Stevenson

Second Advisor

Dr. Raymond N. Dominey

Abstract

This report describes the efforts in the Stevenson Lab to optimize a new sensor built to sample hydrophobic pollutants in water. The sensor known as the Semi-Permeable Membrane Device-Fiber Optic Sensor (SPMD-FOS), integrates the principles of passive sampling and fluorescence spectroscopy to create a real time measurement instrument capable of sens[ing] trace levels of hydrophobic pollutants in water. The optimization of the sensor included changing various aspects of the sensor and the type of experiments in order to get the most reproducible experiment that yielded a high signal for a given concentration. In this report, the type of liquid was inside the membrane was investigated. Triolein, octanol, and water were investigated as membrane liquids and triolein gave the best signal and best reproducibility with a relative standard deviation = 1%. Calibration curves were constructed using the various liquids in the membrane. Triolein gave much more linear calibration curves. Changing the deviation calibration curves experiments from six minutes to 15 minutes improved the linear dynamic range of the sensor as well. An investigation of the effect of sample size on the calibration curve showed that the 100 ml sample size produced a lot of uncertainty and did not follow the pattern of a linear increase of the slope with increasing sample size. Longer experiments (12 hours) were also conducted that revealed the uptake mechanism of an SPMD sensor which has not been done before. In addition, an interesting result that does not follow Fick’s Law was also observed, which is currently under investigation.

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