Document Type
Thesis - University Access Only
Award Date
2006
Degree Name
Doctor of Philosophy (PhD)
Department / School
Chemistry
Abstract
Polycyclic aromatic hydrocarbons (P AHs) are byproducts of anthropogenic combustion processes. Many PAHs are suspected of being or have been confirmed as toxic substances. When emitted into the atmosphere, they either stay in the gaseous phase or sorb to an aerosol particle and are capable of being transported long distances before being deposited into the environment. P AHs have even been found in environmental samples from extremely remote locations. A major deposition mechanism is via scavenging by precipitation. Concentrations of individual PAHs in precipitation have been measured at levels in the low part per trillion. P AH analysis methods used for precipitation samples today involve analyzing dissolved PAHs separately from sorbed PAHs. The objective of this study was to develop an analytical method that combines both dissolved and sorbed P AHs into one extract that can be measured at ultratrace levels. Subcritical water extraction utilizes the precipitation itself as a solvent to dissolve sorbed P AHs. Temperature and modifier addition were identified as important subcritical water extraction variables and studied using a simulated precipitation sample. Dissolved P AHs are collected on a solid phase extraction column, eluted with organic solvent, and analyzed using GC-MS. To improve limits of detection, a large volume injection technique was employed. The optimized method was tested on snow samples collected from three different snow events during the winter of 2005 - 2006. Results confirm the ability to measure P AH levels near the calculated limit of detection, indicate good reproducibility and similar P AH sources.
Library of Congress Subject Headings
Polycyclic aromatic hydrocarbons -- Measurement
Polycyclic aromatic hydrocarbons -- Environmental aspects
Environmental monitoring
Extraction (Chemistry)
Snow -- Analysis
Format
application/pdf
Number of Pages
152
Publisher
South Dakota State University
Recommended Citation
Ferris, David G., "Dynamic Subcritical Water Extraction, GC-MS Analysis of Polycyclic Aromatic Hydrocarbons in Precipitation" (2006). Electronic Theses and Dissertations. 1268.
https://openprairie.sdstate.edu/etd2/1268