Chemistry and Environmental Sciences 2009 Senior Thesis Symposium
Saturday April 18, 2009
9:00 a.m. to 11:30 a.m.
Crawford Hall Room 304
Geospatial Analysis of Indoor Radon Concentrations in Chippewa County, Michigan
Amy Cousino, Mt. Clemens, MI
From a street-level database of residential radon measurements in Sault Sainte Marie, Michigan, this study identified areas of increased radon risk as well as examined the utility of soil properties in predicting residential radon concentrations. Map information was combined with street addresses in order to locate a point uniquely through geocoding, which converted a list of addresses into point data. The data was explored by examining the distribution of the data, by identifying the trends in the data and by attempting to understand spatial autocorrelation and directional influences. Kriging (spatial interpolation) was used to generate an estimated radon concentration surface from the geocoded points and to identify areas that exceeded the threshold limit of 4 pCi/L. A correlation test was performed in order to test the strength of the relationship between the dependent variable of radon concentration and selected soil attributes such as soil permeability and clay content. Multiple linear regression and geographically weighted multiple linear regression analyses revealed no models with high R-squared values or statistically significant coefficients at a p-value of 0.05.
Determination of Microcystin in Algal Supplements via ELISA
Christopher Gault, Detroit, MI
Upon testing algal supplement material to meet the Oregon State regulation of 1997, batches were discovered to be unfit for sale after testing positive for microcystin by ELISA. The microcystin ELISA is a sensitive but non-selective detection method. Samples were taken through liquid extraction and an unknown microcystin variant was isolated by HPLC and identified by UV spectrum. Retention time indicates extreme hydrophilicity compared to known microcystin variants. Molecular mass was determined via LC/MS to be 1100 amu, which does not correspond to any known microcystin variant. Initial observations suggest unknown microcystin is unstable at room temperature.
Synthesis of erythro-2-methyl-3-methoxy-4-phenyl butyric acid (MMPB) for use as a Microcycstin Surrogate
Mallory Green, Livingston, MI
Microcystin is the most common toxin found produced by cyanobacteria (blue-green algae). There have been many studies done on determining the concentration of microcystin in water samples. This study was performed to find a way to determine the concentration of microcystin in sediment and tissue samples. The MMPB was synthesized by the oxidation of Microcystin-LR’s Adda amino acid. Once the MMPB was synthesized and isolated by high performance liquid chromatography (HPLC). Once the product was isolated the MMPB was derivatized and verified by the GC/MS. This method will later be used to determine the concentration of microcystin in sediment, tissue and serum samples.
Applications of Porous Metal Oxide Catalysts Derived from Hydrotalcite Precursors in Alternative Fuel Production
Charlie Johnson, Gaylord, MI
Alternative fuel from renewable, non-food sources is becoming of greater importance as energy costs rise and concerns about the environment increase. Described in this work are new solid base catalysts derived from non-precious metals that are active in the processes producing alternative fuels. These catalysts were prepared by substituting different transition metals into the Mg/Al layered double hydroxide lattices of hydrotalcites and calcining to obtain porous metal oxides. First discussed is an iron doped porous metal oxide catalyst (PMO) that can catalyze the transesterification of triglycerides, the main step in biodiesel production. Second is a copper doped PMO catalyst than has achieved reductive depolymerization of a series of lignin model compounds. Chemical methods for the depolymerization of lignocellulose have been very elusive but the copper doped PMO catalyst discussed here shows hope in attaining that goal.
Coffee Break 10:00 -10:15 a.m.
10:15 -10:30Accumulation of Heavy Metals in Predatory Fish and their Intestinal Parasites Jenna Judnich, Lake Linden Michigan The use of parasites as indicators for heavy metal contamination in aquatic setting is an area of growing research. We determined heavy metal concentration from fish skeletal muscle, intestinal parasites of the fish and then assessed the role of the host-parasite relationship on bioaccumulation of metals. Fish and their intestinal parasites from two sites of known pollution, were collected, digested and then analyzed using an ICP-MS. Overall, parasites showed higher concentrations of heavy metals than their hosts. This suggests that parasites bioaccumulate heavy metals at higher rates than the hosts, much like higher predator-prey bioaccumulation models.
Caffeine as an Indicator of Groundwater Under the Influence of Surface Water in Private Wells
Traci Hoekstra, Shelbyville, MI
An in-house method for determining caffeine concentrations in groundwater and surface water samples was developed. Caffeine was extracted from a 1-L sample using a porous glass fiber membrane embedded with C-18 modified silica particles, eluted with ethylene chloride and methanol and analyzed by high-performance liquid chromatography with photodiode-array detection (HPLC/PDA). The instrument and method detection limits were 2.7 μgL-1 and 18 μgL-1, respectively. This viable in-house method for determining caffeine concentrations in groundwater and surface water samples takes half the time of the other previously published methods.
10:45 -11:00 a.m.
Analysis of Phosphorus Levels in Hatchery Fish and Fish Feed
James Green, Petoskey, MI
The Platte River Fish hatchery is conducting a phosphorus mass balance study to determine their impact on the river. The missing phosphorous sink in their analysis is the amount of phosphorus in the fish themselves. They also are interested in the amount of phosphorus in the fish feed they use. This is to prevent having an excess of phosphorus in the fish which will ultimately end up in the water system. Thirty Chinook salmon a month for four months were analyzed along with twelve different types of fish food. The samples were digested using a Lachat method and phosphorus concentrations were determined using standard method 4500-P.
11:00 -11:15 a.m.
Method Development for Extraction of Pesticides from Soils
Elizabeth Hannah, Lansing, MI
Contamination of soils and water sources by pesticides is of environmental concern. Bay Mills Tribe proposed to investigate the environmental impact of the pesticides used by the tribal community. The list of pesticides contains azoxystrobin, chlorothalonil, chlorpyralid, chlorpyrifos, and MCPA. Although DDT is no longer used, it has adverse environmental health impacts and has a long environmental half life. For this reason, DDT was added to the list of pesticides for method development. After review of the literature, two extraction methods were evaluated; a hexane extraction and a methylene chloride/acetone extraction. The methyl chloride/acetone extraction had better recoveries and was selected for use. The samples were analyzed using GC-MS in SIM to determine the type and concentration of each pesticide.
11:15 -11:30 a.m.
A Spatial and Temporal Analysis of Pesticide Levels in Waishkey Bay Tributary Sediments
Ben Zoppa, Rockford, MI
Stream sediment sampling for pesticides is a yet understudied technique for evaluating pesticide contamination in watershed systems. Most research on pesticide contamination has been performed on water samples, and does not account for sediment partitioning or products of decomposition that may linger in sediments. This research set out to analyze pesticide levels in several tributaries of the Waishkey Bay in Brimley, Michigan using sediment coring and subsequent analysis via solvent extraction and GC/MS methods previously unused for this type of sediment research. Strong correlations were found in the final data suggesting links between pesticide levels and time of sampling, as well pesticide levels and surrounding land use. However, sample size was limited, and the extraction methods used are relatively new. Future studies are required to refine this data, as well as add statistical power.