Date of Award

8-2013

Level of Access

Campus-Only Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

Advisor

Howard H. Patterson

Second Committee Member

Scott Collins

Third Committee Member

Adria Elskus

Abstract

Pharmaceutical and personal care products (PPCPs) and volatile organic compounds (VOCs) are common contaminants in the environment. Methods designed to inexpensively and rapidly detect them are important to reducing human exposure and limiting environmental impact. In this work, synchronous scan fluorescence spectroscopy (SSFS) and fluorescence excitation emission matrix (EEM) spectroscopy combined with parallel factor analysis (PARAFAC) are used to quantify and characterize these pollutants in natural water. Limits of detection at 10-10 M concentrations, comparable to more complex and expensive bench top methods, were established with PARAFAC analysis of EEMs following solvent extraction/concentration.

A fraction of PPCPs in natural water are bound to dissolved organic matter (DOM) significantly affecting the ability to measure them via luminescence spectroscopy. Binding is influenced by both the DOM type and the solution chemistry of the water. The extent of this influence is quantified by Stern-Volmer analysis using different types of DOM and varying conditions of pH and ionic strength. The hydrophobicity of the DOM type had the strongest influence on binding and was magnified by changes in water chemistry. PARAFAC analysis of the DOM-PPCP interaction showed that the higher molecular weight fractions of the DOM were affected most by changes in water chemistry and by increased pollutant concentration. The binding between PPCPs and DOM is a first order rate reaction with respect to PPCP concentration.

Rapid detection of VOCs in the air is critical for a host of applications from homeland security to aiding of environmental protection and human health. The development of copper (I) iodide films for VOC detection is examined. Binding of various volatile amine and sulfide nucleophiles to the copper centers modulates the unique photophysics of Cu(I) that gives rise to a wide range of luminescence emission responses in the visible range. The emission which normally occurs in the UV range for certain Cu(I) salts is shifted to the visible range upon nucleophile absorption. Different amines and sulfides induce different colors. In some cases similar compounds produce different colors, making these metal anion motifs potential sensors for VOC detection in the environment.

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