Mary obtained her doctorate in chemistry at Oregon State University in early 2017. Her area of concentration is analytical chemistry, and she is interested in the transport, transformation, and remediation of environmental contaminants. Prior to her graduate studies, she worked in both government and industry performing analysis of small molecules in biological matrices. Mary joined the Simonich laboratory this spring as a post-doctoral research associate. One of her first contributions to the Superfund Research Program will be the development of a high performance liquid chromatography-mass spectrometry (HPLC-MS) method for analysis of hydroxylated polycyclic aromatic hydrocarbons (OHPAHs) in aqueous systems.
Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants generated by the incomplete combustion of organic compounds, such as those found in fossil fuels and cigarette smoke. Several PAHs have been identified as mutagens or probable carcinogens, and chronic exposure to these compounds is associated with increased risk of developing lung cancer and peripheral arterial disease. PAHs are metabolized by mammals and some microbes to form hydroxylated PAHs, or OHPAHs. Some OHPAHs are more carcinogenic than their parent compounds, because they can cause oxidative damage to DNA, resulting in cell mutations. Microbial transformation of PAHs to OHPAHs should thus be considered when evaluating the effectiveness of bioremediation strategies. Gas chromatography (GC) is typically used for separation of parent PAHs in complex environmental matrices. Following separation on a GC column, the PAHs can be detected and quantified by mass spectrometry (MS). However, analysis of OHPAHs by GC-MS is not as straightforward. OHPAHs must be chemically modified, or derivatized, prior to separation by GC. Derivatization increases sample processing time, and it can complicate identification and quantification of target compounds. Reverse phase high performance liquid chromatography-mass spectrometry (HPLC-MS) circumvents the need for derivatization. OHPAHs can be separated and quantified by HPLC-MS without modification, resulting in shorter analysis times and improved separation.