Defense Date

3-24-2021

Graduation Date

Spring 5-7-2021

Availability

Immediate Access

Submission Type

dissertation

Degree Name

PhD

Department

Chemistry and Biochemistry

School

Bayer School of Natural and Environmental Sciences

Committee Chair

Skip Kingston

Committee Member

Michael Van Stipdonk

Committee Member

Stephanie Wetzel

Committee Member

Stephen Benchouk

Abstract

A method was developed to quantify persistent organic pollutants (POPs) in a wide range of matrices including wastewater, dietary supplements, and human whole blood using stir-bar sorptive extraction, GC-MS/MS, and isotope dilution mass spectrometry (IDMS). The method enabled accurate, precise, sensitive, and efficient quantification of POPs in these matrices. Compared with calibration curves, IDMS provided measurements with a higher level of accuracy and precision, especially at lower measured concentrations. The use of GC-MS/MS enabled a lower limit of quantification compared with GC-MS. A reverse-IDMS method was performed to further eliminate biases from the labelled concentrations of the commercially available standards.

12 commercially available plant-extract based dietary supplement samples were analyzed using this method. Polycyclic aromatic hydrocarbons (PAHs) including naphthalene, acenaphthene, phenanthrene, and benzo[a]pyrene were detected in most of the products with mean concentrations over 1 ng/g. Organochlorine pesticides (OCPs) were detected less frequently than PAHs in these products, and none of the OCPs had mean concentrations over 1 ng/g. These results were compared with existing guidelines and none of the analytes in the samples were found to be above the daily allowable limits. The method was also applied to analysis of 10 human whole blood samples acquired from a blood bank in Northern California. On average, 10 POPs were detected in each sample. The mean xenobiotic body-burden was calculated for each sample and ranged from 0.719 to 1.12 ng/g. This method has demonstrated analytical advantages and will be further applied in the study of environmental and human health.

Language

English

Included in

Chemistry Commons

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