Gas chromatography - mass spectrometry (GC-MS) is a widely used analytical technique for separating and identifying volatile and semi-volatile compounds in complex mixtures. It is beneficial to research ways of increasing sample throughput (i.e. decreasing analysis time) while not losing any chemical information. This study investigates the change in volatile chemicals (odors) that are emitted from banana peels in varying stages of ripeness. The headspace of banana peels was first analyzed using Solid Phase Micro-Extraction (SPME) with a standard gas chromatograph and a quadrupole mass spectrometer (qMS). For demonstrating a viable platform for increased sample throughput, the samples were then analyzed on a LTM (Low Thermal Mass GC) coupled to a Time-of-Flight mass spectrometer. The banana peel analyses on the LTM-TOFMS decreases the run time by tenfold when compared with the traditional GC-qMS. A new data analysis program developed by the Synovec Lab is used to visualize the data and identify compounds.

Proton-coupled electron transfer (PCET) occurs in a variety of oxidation/reduction reactions. This thermodynamically-coupled transfer of an electron (e–) and a proton (H⁺) is important for many reactions, including catalysis and energy generation, and may occur through different mechanisms. Zinc oxide (ZnO) nanoparticles are useful for studying factors that influence the rates of PCET reactions in at metal-oxide surfaces. The ZnO nanoparticles used in this research have been well characterized and, as a colloidal solution, can be treated as molecule-like reactants in experiments. The ZnO nanoparticles described in these experiments are capped with dodecylamine (DDA), and then dispersed into air-free toluene, an aprotic solvent. The use of an aprotic solvent is important to ensure that the e–/H⁺ are transferred from the nanoparticle. When these nanoparticle solutions are irradiated with above-bandgap radiation, an electron is excited into the conduction band. This leaves a hole in the valence band that, from previously demonstrated research, is immediately quenched by EtOH left over from synthesis; EtOH provides both an electron and a proton, keeping the nanoparticle neutral. When the reduced and protonated ZnO nanoparticles are reacted with 2,4,6-tri-tert-butylphenoxyl (^tBu₃ArO·), an electron and a proton are transferred from the reduced ZnO nanoparticle to the ^tBu₃ArO·, yielding the corresponding phenol, ^tBu₃ArOH. The kinetics of this reaction are monitored using laser flash photolysis. The rates of PCET are affected by the reduction potentials and the pKa of the reactants. The reduction potentials of the nanoparticles may be tuned by changing the particle size. Initial results also show the concentration of the capping group affects the rate of PCET. We are investigating how these factors, reduction potential and capping group concentration, influence the rate of PCET from reduced and protonated ZnO nanoparticles.

Levels of atmospheric carbon dioxide have been steadily increasing for decades, sparking the interest of many. In response, researchers have been studying the various components of the carbon cycle, including bodies of water as they act as both significant sinks and sources of carbon dioxide. This study examines the correlation between various water quality indicators and CO₂ flux within the Cedar-Sammamish watershed. At each site, CO₂ flux was measured and logged using an IRGA (Infrared Gas Analyzer) connected to a Plexiglas chamber dome floating on the surface of the water. Dissolved oxygen (DO) levels and pH were measured using Hach DO and pH meters, and water quality was measured using a field spectrometer.  Meteorological data and visual observations were also recorded.  Data was then analyzed for trends.  Preliminary data indicated a positive correlation between nitrate levels and carbon dioxide efflux.  Subsequent data has not necessarily followed this trend, indicating that other factors may be at work.  Understanding the various trends and possible predictors of CO₂ flux is important, as it will help create better models for global carbon cycling.

Polymeric micelles are nanoscopic structures constructed with amphiphilic diblock copolymers constructed with hydrophobic and hydrophillic portions that spontaneously form micelles in solution. Small hydrophobic molecules, such as cancer drugs taxol and doxorubicin, can be encapsulated in the micelle, which effectively serves as a nanovehicle for drug delivery. Here, we will develop a diblock copolymer integrating polyurethane-based self-immolative polymers (SIPs). SIPs are polymers that sequentially disassemble into their building blocks once the disassembly process is initiated by a triggering event at the trigger head group. By using SIPs, the polymers that make up the micelle are designed to depolymerize which we hope to increase the efficacy of payload release and remove the ability for micelle reformation. For this project, the micelle and all parts of the system will be synthesized from the bottom-up; optimizing the molecular weight of the diblock for micelle formation, investigating the kinetics of depolymerization and thermal trigger activation, and examining the stability of the micelle.

Low oxygen concentrations in oceans exist at mid-latitudes where water circulation occurs sluggishly, causing oxygen minimum zones (OMZ’s) to form. Recent trends suggest that OMZ’s are expanding, which could decrease biodiversity, disrupt food chains, and alter seafood industries. The low oxygen content causes OMZ’s to host denitrification, a process in which organisms use nitrate rather than oxygen in cellular respiration. Understanding these rates of denitrification will allow us to predict the consequences of climate change on nutrient cycling and ocean productivity. Autonomous floats with chemical sensors are currently being designed to quantify the rates of denitrification. To ensure that future oxygen measurements will be highly accurate, I calibrated the oxygen sensor using the Winkler method, a chemical procedure. A new amperometric titration Winkler kit was used on the R/V Oceanus to analyze saltwater and freshwater samples near the Columbia River. The data showed that as the temperature and salinity of the samples increased, oxygen content decreased. These samples had oxygen concentrations in the range of 2.4 to 6.0 mL O₂/L H₂O with approximately 1% precision. For optimization of oxygen measurements in OMZ’s, past publications suggested diluting chemicals as well as adding sodium azide. I conducted a dilution experiment involving the Winkler titrant, sodium thiosulfate. OMZ water was created in the lab by adding sucrose to seawater and measuring the oxygen content with an optode, which reported around 2% O₂ saturation. This sample was analyzed using Winkler chemicals with a tenth of the baseline concentration. However, this experiment was limited by the titration system parameters and significant data could not be collected. Revision of the system programming is necessary to finish the experiment. Additionally, further research with the sodium azide modification will increase the accuracy of oxygen measurements in OMZ's and therefore greatly advance the calibration of the oxygen sensor.

Composites of conjugated polymers with semiconducting nanocrystals (NCs) are of interest for low-cost, solution- processable photovoltaics. However, compared to typical polymer/fullerene composites, relatively little is known about factors influencing charge generation. Without understanding these factors, design principles for improving solar cell applications remain elusive. Previous studies of blends of the polymer poly(3-hexylthiophene-2,5-diyl) (P3HT) with PbS nanocrystal quantum dots showed the excited NC undergoing charge transfer by hole transfer from the NCs to the polymer. To further investigate this hole transfer mechanism, quasi-steady-state PhotoInduced Absorption (PIA) was performed on blends of P3HT with PbS nanocrystal quantum dots as a function of excitation energy. As the energy exciting the PbS quantum dots was increased, the yield, per photon absorbed, of positive charge carriers on the organic host polymer increased. This occurred even at excitation wavelengths that only the NCs could absorb at. Our result provide direct evidence that holes generated on the NC retain some of the additional energy from excitation, e.g. hot holes. Further understanding of these results could provide even more insight to the mechanisms of organic/inorganic photovoltaics.

Solar technology is a potential way to help meet the growing demand for clean, renewable energy. Hybrid composites of inorganic quantum dots, with organic semiconducting polymers, offer a potential means of producing low-cost, solution-processable photovoltaics. Photovoltaics can convert sunlight directly into electricity to capture solar energy. The synthesis of quantum dots typically involves the use of large surfactant molecules to facilitate particle growth and solubility. These native ligands act as electrical insulators that impede charge transport in photovoltaic devices. Therefore, it is necessary to exchange these large ligands with small molecules to achieve efficient charge carrier photogeneration and transport. In this research, we examine bulk heterojunction blends of low band gap PbS quantum dots with the conjugated polymer poly((4,8-bis(octyloxy)benzo(1,2-b:4,5-b')dithiophene-2,6-diyl)(2-((dodecyloxy)carbonyl)thieno(3,4-b)thiophenediyl)) (PTB1) treated with different ligands including halide ions and organic crosslinkers. By using photoinduced absorption and transient photovoltage techniques, we study the long-lived charge generation dynamics and recombination kinetics of our devices. We find that the ligand treatments exhibiting higher device performance correlate to longer carrier recombination lifetimes in both spectroscopic and photovoltaic device measurements.

Compound I is the intermediate responsible for substrate oxidation in the catalytic cycles of a variety of heme-containing metalloenzymes, such as peroxidases, oxygenases, and importantly, cytochrome P450s. Cytochrome P450s, through compound I, oxidize approximately 75% of foreign substances that enter the body, such as pharmaceuticals and chemicals from the environment, so there is an interest in the mechanism by which this reaction occurs. The goal of this project is to probe the potential reversibility of Compound I formation, a step traditionally thought to be irreversible. Due to its stability and availability, horseradish peroxidase (HRP) was used as the model enzyme. In the case of HRP, hydrogen peroxide is reduced to water at the heme cofactor, while oxidizing a variety of substrates. In the presence of an oxidant and the absence of a substrate to oxidize, hydrogen peroxide coordinates to the iron of the heme, the O-O bond is cleaved, which forms water and compound I. A key experiment reacts HRP with unlabeled H₂O₂ in ¹⁸O-labeled water, and determines whether mixed-labled H₂O₂ is formed. The presence of mixed-labeled H₂O₂ indicates that there is reversibility of the O-O bond cleavage that forms compound I. The existence of mixed-labeled H₂O₂ is ascertained by first removing HRP by filtration, leaving the H₂O₂ in the filtrate. This is followed by the addition of a water soluble phosphine. In this case, the phosphine cannot be oxidized by Compound I, but can readily react with free hydrogen peroxide in solution to give the corresponding phosphine oxide. Mass spectroscopy is used to determine whether the phosphine oxide has incorporated the ¹⁸O label. Results show that when the experiment is performed in the presence of ¹⁸OH₂, there was no observable increase in the intensity of a peak corresponding to ¹⁸O-phosphine oxide, so reversibility of Compound I formation was not confirmed.

Ion mobility mass spectrometry is a powerful technique for analyzing proteins and protein complexes in the gas phase. Ions are generated using nanoelectrospray ionization from aqueous, buffered solutions containing the protein or protein complex of interest. The resulting ions are native-like; their structures have low, narrow charge-state distributions and resemble those in the condensed-phase. There is an interest in probing different charge states of protein and protein complexes. High charge-state distributions of proteins and protein complexes, for example, can be seen after addition of ‘supercharging’ reagents, e.g., sulfolane or m-nitrobenzyl alcohol, to the electrospray buffer. Several mechanisms have been proposed to explain the mechanism of supercharging. Here, we used ion mobility mass spectrometry to probe the charge-state distributions and collision cross sections of a large set of native-like protein and protein complex ions, with masses ranging from 6–468 kDa, generated from solutions containing 1% m-nitrobenzyl alcohol. We determined the extent of supercharging by calculating the percent increase in highest charge state observed between supercharged and non-supercharged cations. We observed a large range of percent increases in highest charge state but in general, there is evidence that small proteins (<100 kDa) exhibited a greater increase than larger proteins in these experiments. Upon comparison of these results to those for ions generated from sulfolane-containing solutions, we found that the maximum extent of supercharging observed with m-nitrobenzyl alcohol was less than that observed when sulfolane was used. The most supercharged cations generated with m-nitrobenzyl alcohol had up to a 96% increase in collision cross section compared to ions generated without supercharging agents, but the differences in collision cross sections with and without supercharging were less than 2% for large protein complexes (> 100 kDa). These results suggest that ions supercharged using m-nitrobenzyl alcohol may retain their structures better than those supercharged using sulfolane.

Two-methoxyestradiol (2ME or 2ME2) is a highly water insoluble metabolite of estrogen, which possesses antiangiogenic activity and can upregulate death receptor 5 and interferon-signalling pathway, exhibiting anticancer effects. It is practically water insoluble and drug crystals milled to nano-size are evaluated in humans without success to date. While 2ME can inhibit tumor growth, its insolubility (<1ug/ml) may relate to low oral bioavailability. Some studies used vehicles to improve bioavailability. To address insolubility and improve antitumor activity, we evaluated 2ME’s ability to be incorporated into lipid nanoparticles (LNPs) that have been shown to be safe and to provide some tumor cell selectivity. To do so, we investigated different lipid compositions in their abilities to incorporate water-insoluble 2ME. The drug-lipid particles were made with solvent evaporation and hydration method. The free 2ME was removed to determine the degree of drug incorporation into LNP. Drug concentrations were determined with a high-performance chromatography (HPLC) assay. The LNP particle diameter was measured by photon correlation spectroscopy. Among tested lipid compositions, DSPC and DSPE-PEG2000 mixture provided about 80% drug incorporation at drug-to-lipid mole ratio of 1:6. The diameters of the 2ME-LNPs were 47.2±7.2nm. The anti-cancer activity was evaluated in two cell lines, MDA-MB-231 and A549. The 50% effective drug concentration to inhibit cell growth or EC50 of 2ME in MDA-MB-231 breast cancer cells were 0.83µM and 32.4µM for free and LNP respectively. For lung cancer A5492 cells, EC50 was recorded at 2.13 and 3.35 µM respectively for free vs. LNP formulation. These results demonstrated that (1) lipid incorporation overcomes 2ME water insolubility and (2) the drug-lipid particles provide high (~80%) incorporation efficiency thus likely reducing the overall cost, (3) a stable lipid-drug formulation that can be easily scaled and (4) the antitumor cell potency may vary with different cancer cells.

Localized surface plasmon resonances (LSPRs) can be described as oscillations of large electron densities. Traditionally observed in metals, LSPRs have recently been observed in semiconductors, and have gained more attention because of their tunability over a wide range of energies. Additionally, semiconductor LSPRs could offer a cheaper alternative to plasmonic applications. Here, we aim to observe the effect of band-gap engineering on LSPRs in zinc oxide semiconductor nanocrystals by incorporating Cd^{2 +} and Mg^{2 +} ions into zinc oxide host lattices. Cd^{2 +} -and Mg^{2 +} -doped zinc oxides of different molar dopant ratios are synthesized via base-initiated hydrolysis and air-free hot injection synthesis. The size and structure of the nanocrystals are characterized via transmission electron microscope (TEM), absorption and photoluminescence. The molar dopant ratios of the samples are determined analytically via inductively coupled plasma atomic emission spectroscopy. In order to observe LSPRs in semiconductors, conduction-band electrons are added to the semiconductor nanocrystals via photochemical reduction to give them metallic-like properties. The number of electrons accumulated can be measured by titrating the samples with mild oxidants such as decamethylferrocenium. The LSPRs in the zinc oxide nanocrystals are studied by electron paramagnetic resonance spectroscopy (EPR) and infrared (IR) spectroscopies. In combination with absorption and photoluminescence, EPR is used to measure the conduction-band, valence-band and overall band-gap energies. Using IR spectroscopy, we study how these energies influence the LSPR energies.

Micro RNAs (miRNAs) control translation of certain proteins through degradation of the messenger RNA which code for these proteins. These non coding RNAs are often up-regulated in many forms of cancer and can inhibit the expression of tumor suppressor proteins. The goal of this project is to engineer a protein which can bind to and inhibit the biogenesis of a miRNA-21, which is overexpressed in many cancers. Previous reports have shown that the RNA recognition domain (RRM) of human splicing factor Fox-1 protein has high affinity and specificity for the UGCAUG sequence. We are engineering this RRM to target the stem-loop sequence of precursor miRNA-21. Amino acid site changes were introduced into Fox-1 to generate a protein which will inhibit production of the oncogenic miRNA-21 in cancer cells. This project involves the application of various methods in biochemistry, including PCR site-directed mutagenesis, cell transfection, DNA cloning, protein expression and purification, RNA transcription and purification as well as gel electrophoresis assays and 3-Dimensional structural analyses of protein and RNA through nuclear magnetic resonance studies. Currently, a stable protein has been expressed and the precursor species of miRNA-21 is being prepared to characterize its interaction with the engineered protein biochemically, biophysically and structurally.

As scientific studies have been focusing on generating alternative renewable energy sources, attention has been drawn to the need to store energy from the sun. One strategy is to develop catalysts capable of producing the energy-dense molecule hydrogen from the reduction of water. This kind of solar fuels system would allow for on-demand release of the energy that is stored in the chemical bonds of hydrogen through environmentally benign, carbon-free combustion. We are interested in the potential of catalyzing proton reduction with cobalt in a diimine-dioximato ligand framework. Previous studies on cobalt diglyoxime complexes have demonstrated the viability of such catalysts for proton reduction. Our research is focused on synthesizing bimetallic complexes using the same framework and studying the effect of another metal center on catalytic activity. Our entry into this chemistry relies on the initial synthesis of a doubly-deprotonated diimine dioximate complex of cobalt as a starting material, which can be considered as a “metalloligand”. The physical and electronic properties of this cobalt metalloligand and its multimetallic derivatives are studied by X-ray crystallography, 1H- and 13C-NMR, UV-visible spectroscopy, and cyclic voltammetry.

An efficient and environmentally benign means of creating semiconducting polymers is necessary for the commercialization of organic electronics. Furthermore, it is crucial that as much control as possible be exerted over the polymerization process. To these ends, two polymerization methods are useful – C-H activation and living polymerization. First, C-H activation is a collection of synthetic techniques where C-H bonds undergo direct catalytic alteration to yield new homo- or heteroatom linkages. Whereas organometallic reagents were traditionally used to achieve these results, C-H activation allows for shorter syntheses utilizing less-hazardous reagents and broader functional group compatibility. Living polymerization is a form of addition polymerization and in our case, the number of chains is constant during the reaction and dependent on the catalyst-to-monomer ratio. This allows for much narrower mass distributions of the desired polymer and more consistent growth. To achieve this, benzoxazole-based monomers containing a C-O electrophile are to be reacted in the presence of a zero-valent nickel species with electron-rich phosphine ligands. By increasing the electron density on the metal center, we aim to facilitate a “ring-walking” mechanism at higher temperatures than previously thought possible. Monomer synthesis and polymerization results are detailed.

The amino acid tryptophan can participate in biological reactions as a reducing agent, in which it as converted to a radical. Tryptophan radicals embedded in proteins can participate in electron transfer chemistry, such as in DNA photolyase and cryptochrome enzymes, or catalytic chemistry, such as in peroxidases enzymes. The properties of tryptophan radicals are heavily dependent on the microenvironment within the protein. The objective of my research is to study how the protein environment can control the properties of tryptophan radicals. For this, I utilize the beta hairpin peptide as a model protein. This system allows for controlled changes to be made near the tryptophan, altering its microenvironment. The effect of these changes are monitored using electron paramagnetic resonance (EPR), a spectroscopy that is sensitive to electron radicals and can help elucidate the specific effects that the protein microenvironment has on the radical.

The Possession Sound, located within the Puget Sound, is a diverse estuarine environment where freshwater from the Snohomish River mixes with the ocean water from the Strait of Juan de Fuca. A key variable that influences fluctuations in an estuary system is tidal stage changes that result in mixing and stratification that influence water chemistry. The working hypothesis is that increased high salinity, cold water during high tide will result in decreased pH and increased dissolved oxygen (D.O.) Data from 2010 to 2013 were collected monthly at the Mukilteo and Mount Baker Terminal stations. YSI 85 and 650 data for salinity, temperature, pH, and D.O. were organized based on tidal stages. The data did not support our hypothesis; trend lines indicate that as tidal stages increase pH increases from 7.5 to 7.6. On average, D.O. decreased as tidal stages increased, from 9.1mg/L to 8.4 mg/L. Chemical levels in the water column are also influenced by phytoplankton through photosynthesis and respiration. Future research will be conducted to determine the correlation between the amount of plankton in the water and the levels of pH and D.O. in the water column.

Currently there is extensive interest in the health of honeybee colonies, both in the United States, and worldwide. A healthy and functioning agricultural system requires honeybees, and bees in turn, require nutritious, diverse forage that includes both nectar and pollen. This study involved analyzing the pollen collected by honeybee colonies maintained on the campus of Edmonds Community College, and matching that with pollen collected directly from local plants. We isolated pollen from honey collected and stored by the bees and also collected pollen directly from cells in the hive. In order to identify the different pollen species, the pollen was chemically extracted and acetolyzed to remove sugars and waxes. The treated pollen was then stained, slide-mounted and viewed by light microscopy. These pollen samples were compared to samples of pollen that were collected directly from local plants as well as to existing pollen databases. Preliminary analysis revealed the presence of pollen from brassica, salvia, and trifolium. We were unable to identify some of the extracted pollen species. During the coming foraging season we will expand our database of locally-collected pollen and will generate a local pollen identification key. This will allow us to conclusively identify all of the pollen found in the hives. Results of this study will help us track what the bees are eating and will inform decisions about what best to plant to insure healthy colonies.

Luminescent solar concentrators (LSCs) are solar energy harvesting devices that promise to revolutionize the next generation of solar energy by separating the task of sunlight absorption from power generation. These devices use phosphors that absorb sunlight and wave-guide reemitted light to photovoltaics (PVs) to generate electricity. One promising class of phosphors is that of doped semiconducting nanocrystals (known as quantum dots) due to their intense absorption and minimal reabsorption of dopant-emitted light. In these materials the semiconductor quantum dot absorbs sunlight and transfers the energy to an emissive dopant to prevent efficiency loss by reabsorption. CdSe quantum dots are well known for their intense absorption across the visible spectrum, and doping with Ytterbium would enable their emission to be used in LSCs. Moreover, the Yb³⁺ ions emit at an energy that is nearly perfectly matched with the bandgap of a silicon PV cell, boosting its efficiency. The focus of my research is the synthesis of Yb³⁺-doped CdSe. Ytterbium is incompatible with the tetrahedral CdSe lattice with respect to its larger oxidation state and coordination preference, and introducing it as a dopant is a challenge that has yet to be solved by the chemistry field. While employing air-free Schlenck techniques, I am modifying the doping methods that have proven successful in the synthesis of other Gamelin Group materials, including a process we recently developed called nanocrystal diffusion doping. Success can be measured by detecting quantum dot sensitized ytterbium luminescence. The goal is that this approach will lead to a repeatable procedure by which to synthesize stable Yb³⁺-doped CdSe for novel characterizations as well as for eventual application in a new generation of solar devices.

American Indians and Alaska Natives suffer disproportionately from end-stage renal disease. For those with chronic kidney disease, transplantation may be the most effective treatment option. However, Native people do not donate organs at a rate that is commensurate with the need in the population. We developed a semi-structured, 10-question interview guide and used it to facilitate interviews with American Indians on their experiences with community activities to promote awareness of organ and tissue donation. Our nine key informants were project partners at Tribal Colleges and Universities and other tribal leaders. According to our informants, successful strategies to promote donation awareness included community engagement and active listening. Challenges included cultural beliefs and fear of discussing organ donation and death. However, community perceptions of living donation were positive, and key informants felt that living donation should be emphasized in future efforts. More education on organ and tissue donation is needed in Native communities. Information on living donation should be included in future educational efforts as part of the strategy to reduce donor shortages.

Polymerases epsilon and delta are responsible for replicating the leading and lagging strands of DNA, respectively. Accurate DNA replication occurs through Watson-Crick base pairing catalyzed by the enzymes’ polymerase domains, and also through the action of the polymerases’ exonuclease (proofreading) domains. The exonuclease domain of polymerase epsilon (POLE) has recently been reported to be mutated in ~4% of sporadic colorectal cancers and is associated with a high frequency of clonal base substitutions throughout the tumor genome. We hypothesize that the extent of mutational heterogeneity within a tumor will be predictive of the likelihood of resistance to any given chemotherapeutic agent and that the mutational heterogeneity due to mutations in POLE may also allow us to clinically stratify patents.The ultimate goal of the project is to identify POLE mutations in a tumor tissue, if applicable, and to find the quantity of mutations to compare with normal tissue and tumor tissue without POLE. I will utilize the newly developed Duplex Sequencing methodology to identify mutations that are present in a small number of cells within a tumor. By independently tagging and sequencing each of the two strands of individual DNA duplexes, this approach greatly reduces the number of errors. As the two strands of DNA are complementary, true mutations should be found at the same position in both strands. I will first identify tumors carrying somatic POLE mutations and use Duplex Sequencing to quantify the subclonal mutational load. My research team and I expect that the extent of mutational heterogeneity will be greatly increased in tumors bearing POLE mutations due to its impairment of proofreading capacity. For the symposium, we hope to present the quantity of sequencing errors in each of the tissues listed above or at least explain the process if we fail to collect the results in time.

 Organic thin-film solar cells have received considerable attention on account of their flexibility, ease of production, and light weight. Recently, modifications of these solar cells’ nanoscale structures has yielded efficiencies higher than 10%. To further improve device efficiency and durability, detailed understanding of the pathways of charge generation and loss (through recombination of opposing charges) is essential. Electron paramagnetic resonance (EPR) spectroscopy, which directly observes radicals and unpaired electrons, including the charge carriers in these solar cells, is a useful tool for the characterization of these pathways. EPR analysis of relevant materials such as P3HT:PCBM blends indicate aspects of charge carrier lifetime and recombination rate that are temperature-dependent. Also, analysis of the variation of EPR spectra with modulation frequency allows us to directly determine the lifetime of excited charge carriers. Combination of this data alongside theoretical modeling of charge generation and recombination allows us to determine parameters such as charge recombination rates. For this purpose, a new method for simulation of an EPR spectrum that allows for computationally-efficient incorporation of radical life times, relaxation times and saturation has been created.