Date of Award

Spring 2017

Thesis Type

Open Access

Degree Name

Honors Bachelor of Arts

Department

Chemistry

Sponsor

Ellane Park

Abstract

In this study, a method was developed to analyze caffeine levels of water samples collected in Miami, Florida. The method was used to determine caffeine concentrations in reclaimed water samples and environmental water samples using on-line solid phase extraction (SPE) high pressure liquid chromatography (HPLC) high resolution mass spectrometry (HRMS). The rising use and disposal of pharmaceuticals and personal care products are becoming a concern as contaminants increasingly enter lakes, streams, and rivers without proper removal by traditional wastewater treatment processes. Caffeine may be used as a chemical tracer to indicate the presence of contamination in water samples and to distinguish between wastewater and water from environmental sources, such as lakes and rivers. In this investigation, caffeine concentration was quantified using SPE-HPLC-HRMS. In addition, dissolved organic matter in samples, which includes caffeine, was qualitatively characterized using fluorescence excitation emission matrices (EEM). After analysis, reclaimed water samples were found to have a caffeine concentration ranging from 76.2 to 1041.21 ng/L with an average of 590.23 ng/L, and samples from the Miami Beach area were found to have a concentration ranging from 10.3 to 2061.61 ng/L with an average of 355.40 ng/L. Additional environmental samples were found to have caffeine concentrations ranging from 6.18 to 190 ng/L. With an elevated concentration in reclaimed water, caffeine can be used to distinguish sources of water based on influences from wastewater. Fluorescent EEMs showed similar fluorescent profiles for reclaimed waters and environmental water samples differing only in intensity. For each sample, intensity was found to correlate with caffeine concentration, suggesting that fluorescent data can be complementary to mass spectral data. The purpose of this study is to understand the occurrence of caffeine at trace concentrations in reclaimed and environmental waters for the ultimate purpose of improving wastewater treatment facilities. Overall, results indicate that caffeine shows potential as an environmental tracer of wastewater contamination in this region.

Rights Holder

Stephanie Spence

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