Investigating Systems of Varying Complexity Using Multidimensional Fluorescence and Parallel Factor Analysis
Chiarelli, Joseph.
2017
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Abstract: Steady-state fluorescence spectroscopy is used with Parallel Factor
Analysis (PARAFAC) to investigate several systems of varying complexity. PARAFAC has been
shown to be a useful tool to investigate multicomponent fluorescence systems. In Chapter 1,
an introduction to molecular fluorescence and PARAFAC is discussed. In Chapter 2, a novel
method to estimate the fluorescence lifetimes ... read morein mixtures of five polycyclic aromatic
hydrocarbons (PAHs): fluorene, pyrene, triphenylene, anthracene, and phenanthrene is
presented. Score values obtained from oxygenated and deoxygenated samples in the analysis
are used to determine Stern-Volmer constants. The determined constants are used to estimate
fluorescence lifetimes of each PAH. An average quenching rate constant is determined using
information from literature sources, to estimate the fluorescence lifetime. The method is
applied to an experiment with gasoline to identify fluorescent components. In Chapter 3,
PARAFAC with soft independent modeling by class analogy (PARAFAC-SIMCA) was used to analyze
fluorescence data from shrimp extracts to create geographic classification schemes for
shrimp from three different locations on the Ecuadorian coast (Pedernales, Cojimies,
Tonchigüe). The extraction process was improved from previous work with the use of
microwave assisted extraction (MAE). This improved the processing rate from 1 sample per
day to 12 samples per day, with minimal changes to other procedures. Each shrimp was
extracted into aqueous and organic solvents. PARAFAC modeling of the fluorescence data
produced a 3-component model for the aqueous samples and a 4-component model for the
organic samples. Using PARAFAC scores from all the aqueous and some organic components,
shrimp samples were classified by site at the 95% confidence level for 91% of samples. In
Chapter 4, cyclodextrin complexes with polycyclic aromatic hydrocarbons (PAHs) are
investigated. Proposed is a method that allows for us to produce separate spectra and
concentration data for free molecules and the complexes. This work specifically focuses on
several complexes of β-cyclodextrin with naphthalene and anthracene. Specifically, 1:1
complexes and 2:2 complexes are investigated. Score values are used to calculate
equilibrium constants for the various complexes and compared to literature data. The method
is shown to be able to investigate mixtures of multiple PAHs with cyclodextrins
simultaneously.
Thesis (Ph.D.)--Tufts University, 2017.
Submitted to the Dept. of Chemistry.
Advisor: Jonathan Kenny.
Committee: Arthur Utz, Sam Thomas III, and M. Thandi Buthelezi.
Keywords: Physical chemistry, Analytical chemistry, and Chemistry.read less - ID:
- n296xb20r
- Component ID:
- tufts:23078
- To Cite:
- TARC Citation Guide EndNote
