Freshwater lakes: Evaluation of a method for fatty acid analysis of surface water
Abstract
Aerosol particles are important components of the atmosphere due to their impact on human health, radiative forcing and biogeochemical cycles. While many studies have been conducted regarding aerosol particles our scientific understanding of them as a whole is relatively limited. A current area of study which has produced significant results focuses on biological activity in marine environments and biologically derived aerosol emissions. It has been found that biologically derived marine aerosols impact the composition and size distribution of marine and costal aerosol populations. Few studies, however, have been conducted to determine if similar interactions take place between freshwater environments and the atmosphere. A previous study conducted in northern Michigan provided evidence for the generation of Aitken mode particles through the bubble bursting mechanism from the surface of Lake Michigan. We hypothesized that indisputable evidence could be compiled which would link freshwater lakes to Aitken mode particle generation through biological marker compounds. Those biological marker compounds that were chosen were, ù-3 fatty acids, as they can be traced back to lake specific diatoms and algae. To test this hypothesis it was necessary to develop and test methods for concentrating fatty acids and converting them to their methyl ester derivative so that they could be separated and detected by way of chromatography. While further research is still needed to form a definitive link between freshwater lakes and Aitken mode particle generation we provide a full evaluation of the method for the extraction and esterification of fatty acids from the surface of freshwater lakes. In addition we provide a partial analysis of the fatty acid composition of field samples collected from the surface of Lake Michigan.
Degree
M.S.
Advisors
Shepson, Purdue University.
Subject Area
Atmospheric Chemistry|Analytical chemistry
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