GK12
MATT ALEXANDER NSF Graduate Fellow
alexmat2@isu.edu
Thesis Title:
Photocatalytic Oxidation of Aqueous Trichloroethylene Using Dye Sensitized Photocatalyst Monitored via Micro-Headspace Solid-Phase Microextraction Gas Chromatography/Electron Capture Detection and Mass Spectrometry

Research Advisor:
Dr. Jeffrey J. Rosentreter

Teacher Partner:
n/a

Degree Sought:
Masters of Science in Chemistry.

University Department and/or Lab:
Working in the Rosentreter lab focusing on environmental and analytical chemistry.

Research Focus:
My research addresses a local ground water contaminant, Trichloroethylene. As such, we have used my research as a means to explore water quality and what can be done to protect the local water quality. Every discussion about water quality has involved questions concerning my research and how the concepts that the students were learning could be used to protect the water quality.

Description of Research:
Trichloroethylene (TCE), a useful industrial agent which unfortunately exhibits carcinogenic properties, has become an extremely prevalent environmental contaminant. As such, new rapid, sensitive, and cost effective detection methods are needed for the identification of potential point sources of contamination. A new analytic micro-headspace method is described, utilizing solid phase micro-extraction (SPME) fibers and routine gas chromatography/electron capture detection (GC/ECD) for the detection of TCE to the 3.89 ppb level in aqueous samples. The polydimethylsiloxane (PDMS) fiber was shown to have the greatest analytical promise, with excellent sensitivity and minimal carry over. This method was employed in the monitoring of the photooxidation of TCE using buoyant TiO2 coated microspheres, which were sensitized using natural anthocyanin dyes obtained from fruits. Solar mediated photoxidation was shown to be a successful method for the removal of aqueous organic contaminants. The dye sensitized system yielded excellent remediation with 93 % of the TCE removed from the system within 12 hours. As irradiation was executed, the expected mineralization product hydrochloric acid was produced, as indicated by a significant drop in pH and positive silver nitrate spot test for chloride ion. Ion chromatography analysis confirmed the evolution of chloride with increasing irradiation times. Overall, the reported micro-headspace SPME offers improved sensitivity over previously published micro-headspace technique, with an improvement of roughly 7000 in the signal to noise ratio.

One example of how you integrate your research into your GK-12 experience:
n/a


Profile date: May 2007

fellow

MATT ALEXANDER
alexmat2@isu.edu