Student Abstracts: Chemistry at PNNL

Growth of Carbon Nanotubes, using Chemical Vapor Deposition. TRAVIS ADAMSON (Brigham Young University, Provo, UT 84602) CHRIS AARDAHL (Pacific Northwest National Laboratory, Richland, WA 99352) .
Carbon nanotubes (CNT's) are a new material which have yet to be entirely researched. No one has fully realized their awesome potential as a new material for the 21st century. CNT's have many potentially valuable physical properties. CNT's are characterized by their high mechanical strength, adjustable electronic properties, high surface area, and light weight. Our project entails growing CNT's on a variety of substrates using a hotwall furnace and a method known as Chemical Vapor Deposition (CVD). The CVD method calls for us to flow ethylene gas, a hydrocarbon, under extreme temperatures in order to deposit carbon on the chosen substrate. The substrate (usually a silicon wafer) is placed inside a quartz tube which runs through the furnace. Ethylene gas is flowed through the tube when the temperature has reached 700 degrees Celsius. In the future, carbon nanotubes could prove very valuable for their abilities to store hydrogen for fuel cells. They could also be used for aerospace engineering, electronic nano- devices, and any number of tasks which are yet to be discovered.

Chitosan/N-isopropylacrylamide graft copolymers for tissue engineering applications. NATHANIEL BAER (Cornell, Ithaca, NY 14853) ANNA GUTOWSKA (Pacific Northwest National Laboratory, Richland, WA 99352) .
Water-soluble chitosans of assorted molecular weights were grafted to different oligomer chain groups with temperature sensitive properties. The solutions were then cleaned and dried. The resulting polymers displaying both water-soluble and temperature sensitive qualities were tested for a variety of properties. Mw determination was tested using Gel Permeation Chromatography. Success of grafting was qualitatively analyzed with an IR machine, utilizing thin films, and Quantitatively estimated by titration of HCl. Use of Rheometer compared strength of gel under increasing temperature. Results from four solutions show that oligomer was successfully grafted onto chitosan. The gelling properties appear dependent to both the brand of chitosan, the amount of oligomer and the success of grafting. The polymers cover a wide range of Mw and respond differently to stress at given temperatures. Further testing of these polymers as well as synthesis of different polymers will give insight into the ability of gels to serve as drug delivery systems inside the human body.

Application of MALDI-MS for Environmental Analysis. KATE BOETTCHER (Oregon State University, Corvallis, OR 97331) JAMES A. CAMPBELL (Pacific Northwest National Laboratory, Richland, WA 99352) .
The analytical techniques presently used to identify unknown compounds are extremely expensive, time consuming, and labor intensive. Techniques are being explored that will save time and expenses. A potential technique is matrix assisted laser desorption ionization- mass spectrometry (MALDI-MS). MALDI-MS is a much quicker and cost efficient way to analyze an entire mass spectrum with a dramatic reduction in sample amounts and hazardous waste than previous methods such as liquid chromatography/mass spectrometry or gas chromatography/mass spectrometry. MALDI-MS allows a one step process to analyze both positive and negative ion modes with minimal preparation. MALDI-MS was used to analyze various low-molecular weight compounds such as amines, nitrosoamines, aromatic, and chlorinated species. Some particular compounds analyzed were nitrosodiphenylamine, dichlorobenzene, naphthalene, and nitrosodimethylamine. The results yielded promising information to help in future applications. Once tests have been run to produce a mass spectrum, the sample needs to be quantitatively analyzed as well. This will allow practical and beneficial operation when taken onto the field.

Fundamental Process Chemistry at Pacific Northwest National Laboratory. KARLYN BOTT (Whitman College, Walla Walla, WA 99362) JOHN LINEHAN (Pacific Northwest National Laboratory, Richland, WA 99352) .
The focus of this appointment was on the carboxylation of alcohols with carbon dioxide to form carbonate salts. Firstly, the solubility of carbon dioxide in methanol was investigated using high pressure proton and 13C NMR. A linear relationship was found between the pressure of carbon dioxide and the amount solvated. Next, carbon dioxide solubility in methanol with a small amount of water was investigated by the same method. The additional water had no effect on the solubility of carbon dioxide. The carbonate salts were made by bubbling carbon dioxide on room temperature mixture of the alcohol to be carboxylated and a base to act as the cation in the product. This carboxylation was performed using various alcohols, including methanol, ethanol, 1-propanol, 2-propanol, t-butyl alcohol, 1-butanol, 1-pentanol, 2-pentanol, 1-hextanol, 1-octanol, ethylene glycol, 2-chloroethanol, 3-chloropropanol, and phenol. 1,8-Diazabicyclo[5.4.0]undec-7-ene and triethylamine were the bases used. The actual carboxylation of the alcohols was investigated through IR and high pressure proton and 13C NMR spectroscopy. IR spectroscopy of the salt product showed peaks that were indicative of carbonate. The high pressure NMR spectra were obtained using a PEEK tube and a carbon dioxide pump.

Quantum Yield Temperature Dependence of the Photodecomposition of Hydrogen Peroxide. AARON BROWN (University of Washington, Seattle, WA 98195) DONALD CAMAIONI (Pacific Northwest National Laboratory, Richland, WA 99352) .
In this experiment, samples of hydrogen peroxide were photolyzed with a high-power excimer laser. Several of these trials were tried at different temperatures and relative quantum yields were calculated from these trials. The temperature dependence was then determined from these quantum yields. A computer model of the photodecomposition of hydrogen peroxide was then made, assuming that there was no effect from solvent viscosity. The theoretical quantum yield was found to be 2 in the model because some resultant hydroxyl radicals promoted further reactions with the hydrogen peroxide. The fact that there is a temperature dependence of the quantum yield shows that the solvent viscosity was hampering the mobility of some of the hydroxyl radicals. Therefore, some radicals were unable to escape the solvent cages and instead collided with each other to reform some hydrogen peroxide, lowering the quantum yield. The temperature dependence of the quantum yield of hydrogen peroxide photodecomposition was found to be linear between 8º C and 35º C.

Thermosensitive hydrogels for medical applications. MEGAN BRUEMMER (Whitman College, Walla Walla, WA 99362) ANNA GUTOWSKA (Pacific Northwest National Laboratory, Richland, WA 99352) .
Degradable and nondegradable thermosensitive hydrogels were studied for application in drug delivery and tissue engineering. Polymers were titrated with acid or base to determine average molecular weight. Titration was also used to determine the composition of newly synthesized polymers for AAc and oNIPA groups. Characteristics of the polymers were also studied. LCST experiments were conducted on a UV/Visible Spectrometer to determine the clouding point curve and temperature of gelation for pure polymers and polymers grafted with chitosan. Nondegradable thermosensitive hydrogels were tested for drug release. Fluorescein Isothiocyanate-Dextran was used to simulate the molecular size of the drug. Samples were kept in a 37°C water bath to match human body temperature. The Dextran was released into phosphate buffer saline solution over a two-week period. Supernatant samples were taken periodically. A UV/Visible Spectrometer analyzed the sample to calculate the amount of Dextran released from the gel disks. Results showed that even the largest Dextran was effectively released from the gel disks. Nondegradable and degradable gels were tested for tissue culture. The same Dextran was used for this study to simulate the cells' ability to exit the gel disks. Further studies in this area will test biodegradable gels for drug release.

Preparation of New Polymer Coatings for Detection of Pertechnetate Ion. COLIN CARVER (Columbia Basin College, Pasco, WA 99301) TIM HUBLER (Pacific Northwest National Laboratory, Richland, WA 99352) .
The general aim of this work is the design and implementation of a new sensor technology for analysis of the complex chemical mixtures found at DOE sites nationwide. The specific goal of this research is the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the Vadose Zone and associated subsurface water at the Hanford site. The sensor design consists of a basic spectroelectrochemical configuration consisting of a waveguide with an optically transparent electrode that is coated with a thin chemically selective film. The films are being developed for pertechnetate ion analysis. Samples containing pertechnetate ion will partition into the films by electrostatic attraction, then electrochemically converted into a Tc coordination compound that gives a strong optical signal associated with an electrochemical reduction/oxidation process. This presentation focuses on strategies for preparation of the selective sensor films.

Preparation of New Polymer Coatings for Detection of Pertechnetate Ion. ALAN COOPER (Columbia Basin College, Pasco, WA 99301) SAMUEL A. BRYAN (Pacific Northwest National Laboratory, Richland, WA 99352) .
The general aim of this work is the design and implementation of a new sensor technology for analysis of the complex chemical mixtures found at DOE sites nationwide. The specific goal of this research is the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the Vadose Zone and associated subsurface water at the Hanford site. The sensor design consists of a basic spectroelectrochemical configuration consisting of a waveguide with an optically transparent electrode that is coated with a thin chemically selective film. The films are being developed for pertechnetate ion analysis. Samples containing pertechnetate ion will partition into the films by electrostatic attraction, then are electrochemically converted into a Tc coordination compound that gives a strong optical signal associated with an electrochemical reduction/oxidation process. This presentation focuses on strategies for preparation of the selective sensor films.

Hartree-Fock and Kohn-Sham orbitals for ionic systems. CARL FAHLSTROM (Eastern Oregon University, LaGrande, OR 97850) JEFF NICHOLS (Pacific Northwest National Laboratory, Richland, WA 99352) .
Density Functional Theory (DFT) allows chemical properties to be determined directly from the calculated electron density. This theory is useful in molecules with a large number of electrons, N, because it formally scales as O(N3) whereas other methods which include electron correlation scale much worse. Hartree-Fock (HF) theory as well as four DFT methods were applied to several hydrogen-bonded complexes and ionic systems. Ionic compounds containing Na, Cl, F, Li, and H were studied. The hydrogen-bonded systems studied were the HF dimer, water dimer, and the H2O-HF complex. The DFT methods compared were Local Density Approximation (LDA), Optimized Energy Potential (OEP) SIC perturbative, and the Generalized Gradient Approximation (GGA). The methods used with ionic systems were HF, LDA and GGA. The Highest Occupied Molecular Orbital (HOMO) energies of the ionic systems were found using each of the methods described. The Hartree-Fock results were plotted against the LDA and GGA results. These plots sh ow a linear relationship between the two methods. There is also a phase shift in the functions that is periodic with the electronegativity of the atoms in the compound. Calculating the energy of the dimer system and subtracting the calculated energy of both monomer units determined the interaction energies of the dimer systems. The energy was calculated at several geometries. These geometries varied by the distance between the two molecules in the dimer. This data was used to make Potential energy curves for each system.

Permanganate Reaction Kinetics. AMBER GAUGER (Lewis-Clark State College, Lewiston, ID 83501) RICHARD T. HALLEN (Pacific Northwest National Laboratory, Richland, WA 99352) .
Tank waste on the Hanford Site contains radioactive elements that need to be removed from solution prior to disposal. One effective way to do this is to precipitate the radioactive elements by permanganate oxidation. When added to tank waste, permanganate, Mn(VII), reacts quickly producing manganese(IV) dioxide precipitate. Because of the speed of the reaction it is difficult to tell what is happening. Individual reactions using non-radioactive reductants found in the tanks were done to determine reaction kinetics. In this project sodium formate, sodium gluconate, EDTA, HEDTA, sodium citrate, glycolic acid, and sorbitol were used as reductants in sodium hydroxide solutions with manganese(II) chloride, iron(III) nitrate, iron(II) chloride, neodymium nitrate, and strontium(II) nitrate as complexing agents in various concentrations. It was determined that HEDTA reacted quickest, followed closely by sorbitol and EDTA, then gluconate, formate, glycolic acid, and lastly citrate. When the complexants were added to the reductants, changes in the rates of the reactions occurred. When the complexants were added to gluconate, manganese(II), strontium(II), and neodymium made the reaction go faster, whereas iron(III) and iron(II) appeared to react at the same rate as when no metal ion was in solution. With EDTA, manganese(II) was the only complexant that made the reaction rate increase, while iron(III) was a little slower, and strontium decreased the reaction rate significantly. With HEDTA, iron(III) did not have an effect on the rate of reaction, while strontium slowed it down considerably. These reactions should determine what happens when permanganate is added to a tank.

Sol-gel synthesis of Cs-Zr-Si and Ba-Zr-Si Polymers. LIBBY HEEB (University of Washington, Seattle, WA 98105) WILLIAM D. SAMUELS (Pacific Northwest National Laboratory, Richland, WA 99352) .
A Cs-Zr-Si waste form is to be used to remove radioactive cesium from tank waste at the Hanford Nuclear Reservation. However, as cesium decays into barium, the waste form's structure deteriorates, causing it to crumble. This is not favorable for waste transportation or storage. A sol-gel process was successfully used to make the Cs-Zr-Si waste form. The same process was used to try to make the same structure with barium instead of cesium. Due to barium's insolubility, this was not successful. However, with more time to complete further research aimed at finding a way to keep barium in solution, it may be possible to first make the barium structure, and then make the structure with some barium and some cesium. These structures could be examined using IR spectroscopy, heated, and then reexamined to determine any structural changes.

Pronghorn 2001: Quantitative Analysis Using Infrared Remote Sensing. COREY HEITSCHMIDT (WSU Tri-Cities, Kennewick, WA 99336) DR. TIM JOHNSON (Pacific Northwest National Laboratory, Richland, WA 99352) .
The development of remote sensing technology to detect chemical plumes is important for environmental and national security purposes and it is thus important to test the sensors and their capabilities under scenarios that represent actual releases of hazardous materials under realistic atmospheric conditions. During the Pronghorn 2001 campaign at the Nevada Test Site HAZMAT Spill Center, PNNL used a passive FTIR remote sensor system to obtain qualitative and quantitative results from controlled releases. PNNL participated in campaign to improve upon 1) its equipment sensitivity, 2) its abilities for remote identification and quantification of gas atmospheric pollutants, and 3) the software evaluation methods used in the detection. The passive system consisted of a Midac M2400 FTIR equipped with a liquid-N2 cooled MCT detector coupled to a 14" telescope to detect the infrared radiation. Data were gathered by recording an "on-plume" segment looking at the chemical emissions followed by an "off-plume" segment, which was used as a background to subtract from the on-plume spectrum. The spectrometer response was calibrated using a pair of blackbodies. The data collection was successful and ppmV mixing ratios were determined for the analytes methanol, tri-chloroethylene, sulfur hexaflouride, and ammonia. The comparison of release rates from HSC and PNNL's calculations have shown that PNNL estimates are typically low by a factor of 2 to 3, but that the qualitative agreement between calculated and measured spectra are excellent. The PNNL estimated concentrations scaled nicely with calculated mixing ratios for all analytes.

DNA Microarray Technologies: A Novel Approach to Genomic Research. ROCHELLE HINMAN (Whitworth College, Spokane, WA 99251) DR. BRIAN THRALL (Pacific Northwest National Laboratory, Richland, WA 99352) .
A cDNA microarray allows biologists to examine the expression of thousands of genes simultaneously. Researchers may analyze the complete transcriptional program of an organism in response to specific physiological or developmental conditions. By design, a cDNA microarray is an experiment with many variables and few controls. One question that inevitably arises when working with a cDNA microarray is data reproducibility. How easy is it to confirm mRNA expression patterns? In this paper, a case study involving the treatment of a murine macrophage RAW 264.7 cell line with tumor necrosis alpha (TNF-a) was used to obtain a rough estimate of data reproducibility. Two trials were examined and a list of genes displaying either a > 2-fold or > 4-fold increase in gene expression were compiled. Variations in signal mean ratios between the two slides were observed. We can assume that erring in reproducibility may be compensated by greater inductive levels of similar genes. Steps taken to obtain results included serum sta rvation of cells before treatment, tests of mRNA for quality/consistency, and data normalization.

Columbia River Recreational Survey 2001. MATTHEW HOERTKORN (Universtiy of Washingotn, Seattle, WA 98195) JIM BECKER (Pacific Northwest National Laboratory, Richland, WA 99352) .
During World War Two, it was believed that their was only one quick way to end the war and that was with the atom bomb; As a result the Hanford site was created. The production of the bomb created nuclear contamination at the Hanford Site and surrounding areas, which is still present to this day. To determine the most effective way to clean up the contamination, research must be done to look at several different substances and variables. One important variable is the amount of exposure that the people living and visiting this area receive from the contamination. The Columbia River Recreational Survey was designed to give an understanding of how river based recreation on the Columbia River affects human exposure to nuclear contamination, and how potential future clean up tactics might affect the economy in the Columbia region. One item gathered from this survey is the types of fish being caught at different places. With this knowledge it can be discovered where the sites Northern Pikeminnow, formerly known as Squawfish, a fish which has a bounty on it, are being caught.

Development of Physiologically Based Pharmacokinetic Model for Chlorobenzene Exposure. MELISSA KANIA (University of Washington, Seattle, WA 98195) KARLA THRALL (Pacific Northwest National Laboratory, Richland, WA 99352) .
Chlorobenzene, a volatile chemical, has been historically used in the manufacture of phenol, aniline, DDT, as a solvent for paints, and as a heat transfer medium. Low levels of chlorobenzene are encountered as environmental contaminants at manufacturing plants, and waste sites. The present study focuses on development of a physiologically based pharmacokinetic (PBPK) model to describe the absorption, distribution, metabolism, and elimination of chlorobenzene in rats. Partition coefficients were experimentally determined in rat tissues and blood samples using an in vitro vial equilibration technique. The ratios indicate that chlorobenzene is highly lipid soluble. Metabolic rate constants were derived from the optimization of a series of in vivo gas uptake curves conducted at various initial chamber concentrations. Pretreatment of animals with pyrazole, an inhibitor of oxidative microsomal metabolism, appeared to inhibit the uptake of chlorobenzene. Studies to evaluate the relationship between chlorophenol (chlorobenzene metabolite) concentration in saliva and urine to chlorobenzene concentration in the blood were conducted. Ultimately this data will be used to develop a PBPK model which could be used to assess chlorobenzene exposures in humans.

Methods Development on the Characterization and Separation of Organic Acids and Chemical Warfare Simulants. JEREMY LOHMAN (Washington State University, Pullman, WA 99337) JAMES A. CAMPBELL (Pacific Northwest National Laboratory, Richland, WA 99352) .
Characterization of tank wastes is an expensive process. New methods need to be developed in order to cut down the cost of characterizing the wastes. Current methods use derivatization and other expensive methods that make relatively large amounts of waste. MALDI MS and capillary electrophoresis are relatively inexpensive ways of characterizing these wastes, without producing more waste because of the small sample sizes. MALDI MS has previously been used to characterize the organic acids in tank waste. MALDI MS also has the potential to be miniaturized for the purpose of analyzing air for chemical warfare compounds. Some of the chemical warfare compounds have the same phosphate backbone as some of the plutonium extracting chemicals. Finding methods of separating the warfare compounds and analyzing by MALDI would also be a step in analyzing the extracting chemicals as well. Developing a method for separating organic acids took some time, because acetate and glycolate coeluted. Finding the right way to analyze the chemical warfare compounds was only impeded because a couple of the compounds fragmented in aqueous solutions. This was overcome by analyzing them without water. The phosphate containing compounds were not affected by water and will possibly be separable by CE. After a method was found for separating acetate and glycolate, the conclusion was made that CE might be better for separating the acids, because it takes two columns to separate them by ion chromatography. A combination of CE and MALDI will be a useful tool for the characterization and separation of components in tank wastes in the future.

Columbia River Recreational Survey 2001. JANIE MARPLES (University of Puget Sound, Tacoma, WA 98406) DANIEL TANO (Pacific Northwest National Laboratory, Richland, WA 99352) .
The Hanford worksite was originally established during the end of World War II when United States scientists were working on the development of the Atom Bomb. The production of the bomb resulted in nuclear contamination that is present today on the Hanford Site and many surrounding areas. In order to determine the most effective and efficient ways to deal with and clean up the contamination, research must be done to understand exactly how much exposure the people living in and visiting this area have to the contamination. The Columbia River Recreational Survey was designed to gain an understanding of how river based recreation on the Columbia affects people's exposure to nuclear contamination, and how potential future clean up tactics might affect the economy in the Columbia region. In order to collect data about how the Columbia River is being used a team of students and staff traveled to 25 recreational sites along the Columbia River and collected observational data and surveys about the recreational habits of the people they encountered at each study location. Future work in this area might include expanding the research area or including different or more detailed types of information on the observation or questionnaire forms.

Determining the In Vitro Rate of Metabolism of 1,2-Diethylbenzene in Rats. ANARGIROS MELETIS (Pacific University, Forest Grove, OR 97116) KARLA THRALL (Pacific Northwest National Laboratory, Richland, WA 99352) .
The in-vitro metabolism of 1,2-diethylbenzene was studied in liver microsomes prepared from male F344 rats. The substrate, 1,2-diethylbenzene, is a compound commonly used in the production of divinylbenzene and has been found in the drinking water supplies of some cities across the United States. 1,2-diethylbenzene is believed to be metabolized to 1,2-diacetylbenzene, which is neurotoxic in laboratory animals. The ability of the microsomes to metabolize 1,2-diethylbenzene in vitro was studied by observing the disappearance of 1,2-diethylbenzene and appearance of 1,2-diacetylbenzene over time. Reference vials containing heat inactivated enzymes and active sample vials were incubated with a mixture of HEPES and NADPH and kept in a temperature-controlled Vortex evaporator. The substrate, 1,2-diethylbenzene, was added as a liquid at 100 or 500 mg/ml (in 2% DMSO) to the vials and then incubated for time intervals ranging between 5 to 150 min. At the end of the incubation period the reaction was stopped, chlorobenzene was added as an internal standard, and the samples were extracted and analyzed on an HP 5890 Series II GC with a photo-ionization detector. The concentration of 1,2-diethylbenzene was found to be lower in the active samples than in the inactive samples. Some samples were pretreated with pyrazole.

Preparation of Carbonate Salts from Alcohols, Carbon Dioxide, and Tertiary Amines. MAIRIN ROONEY (Sacramento City College, Sacramento, CA 95822) JOHN LINEHAN (Pacific Northwest National Laboratory, Richland, WA 99352) .
Historically, carbon dioxide(CO2)has not been regarded as a useful monomer, yet as environmental concerns grow and CO2 remains an abundant industrial byproduct, research and industry have looked toward CO2 for utilization as an inexpensive carbon feedstock. Synthetic applications of alkyl- and polycarbonates exist including pharmaceuticals, and fuels. Typically these items are synthesized using phosgene or organometallic catalysts. Safer and less expensive methods of carbonate alkylation have been explored, yet few methods are practical on an industrial scale. Various alcohols and polyalcohols were dissolved and reacted with a tertiary amine. CO2 was bubbled through; the carbonate salt precipitating out of solution. The salts were washed, filtered, and allowed to dry. Yields were calculated and salts were characterized using Infrared (IR) spectroscopy, 13C and solid state Nuclear Magnetic Resonance (NMR). The salts were observed by IR with strong bands at wavelengths between 1640 and 1650 cm-1. NMR analysis displayed mole fractions of CO2 to alcohol as increasing proportional to CO2 pressure, indicating carbonate salt formation. Yields varied depending upon the alcohol ranging from 11% - 79%. Salts formed from polyalcohols yielded conversion > 100% due to suspected bicarbonate production verified by solid state NMR. Data suggest alcohol and tertiary amines under CO2 form organic salts of alkyl carbonates via a hemi-acid saltand form in greater yield as CO2 pressure increases. Less hindered alcohols or alcohols with strong electron withdrawing groups seem to form carbonate salts in greatest yield with salts formed from polyalcohols requiring further study.

Synthesis and 13C NMR Spectroscopy of Steryl Ferulates and Coumarates in Corn Oil. NICOLE STAIR (Whitman College, Walla Walla, WA 99362) JAMES A. FRANZ (Pacific Northwest National Laboratory, Richland, WA 99352) .
The objective of this study was to synthesize authentic samples of coumarate esters of sterols thought to be found in corn oil. In this study, a fraction of corn oil derived form corn hulls potentially could contain steryl cinnamic acid derivatives of both ferulic and coumaric acid. Two important representatives of corn-oil derived sterols, stigmasterol and stigmastanol, and one structurally similar coumarate, that of cholesterol, were synthesized in order to determine and compare their 13C NMR spectroscopic properties to those observed for extracts of corn fiber. In addition, chromatographic techniques were employed to resolve steryl esters in corn oil. The study revealed that steryl ferulates are present in significant yields in the corn oil, but steryl coumarates were determined to be present in the corn oils at concentrations less than 10% of the ferulates.

Hydroxyapatite-SN15 Binding as a Model For Protein-Mineral Interactions. DANIEL STEVENS (University of Washington, Seattle, WA 98195) XIAOHONG, LI (Pacific Northwest National Laboratory, Richland, WA 99352) .
Past research has found that quantities as small as 0.1% (by weight) of proteins in solution with minerals can drastically alter crystal growth and morphology. This research focused on the interaction of hydroxyapatite (HAP), and the 15 N-terminus amino acids of the statherin protein (SN15). Statherin inhibits mineral deposition on teeth by keeping saliva supersaturated with respect to calcium phosphate. HAP is the phase of calcium phosphate that makes up enamel and parts of bone. One of the primary goals of this research was to determine the secondary structure of SN15 when it is bound to HAP, which could be used to model other mineral-protein interactions. The SN15 peptide was isotopically labeled at L8G12. The peptide was then adsorbed onto HAP. The samples were then analyzed using solid state NMR (peptide structure), fluorometery (peptide coverage), CCK (kinetics), and were also run through zeta potential experiments (charge interactions). A calibration curve was constructed using a fluorometer on samples with known peptide concentrations. The curve was then applied to solutions prior to and after adsorption isotherms to determine coverage. CCK and zeta potential experiments are expected to demonstrate that electrostatic interactions are the primary initiator of HAP-statherin binding, as opposed to crystal face specific sites. Solid State NMR is expected to show that the region of interest on the protein becomes highly helical after binding.

Preparation of New Polymer Coatings for Detection of Pertechnetate Ion. MATTHEW THORNTON (Columbia Basin College, Pasco, WA 99352) TIM HUBLER (Pacific Northwest National Laboratory, Richland, WA 99352) .
The general aim of this work is the design and implementation of a new sensor technology for analysis of the complex chemical mixtures found at DOE sites nationwide. The specific goal of this research is the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the Vadose Zone and associated subsurface water at the Hanford site. The sensor design consists of a basic spectroelectrochemical configuration consisting of a waveguide with an optically transparent electrode that is coated with a thin chemically selective film. The films are being developed for pertechnetate ion analysis. Samples containing pertechnetate ion will partition into the films by electrostatic attraction, then electrochemically converted into a Tc coordination compound that gives a strong optical signal associated with an electrochemical reduction/oxidation process. This presentation focuses on strategies for preparation of the selective sensor films

Protein Mineral Interactions as they Influence Final System Conformation. LINDSEY VANSCHOIACK (Rose-Hulman Institute of Technology, Terre Haute, IN 47803) ALLISON CAMPBELL (Pacific Northwest National Laboratory, Richland, WA 99352) .
Literature evidence suggests that proteins in solution with growing minerals can greatly affect the mineral's morphology. As little as 0.1% wt/wt protein in solution can cause the crystal's size and morphology to be drastically altered. Understanding a protein's secondary structure after formation on a biologically derived mineral would contribute greatly to the current understanding of biomineralization. As a model system to study tooth and bone biominerals, this research focuses on the relationship between structure and surface coverage of a peptide derived from the N terminal 15 amino acids (SN15) of statherin and its biologically relevant mineral calcium phosphate. Statherin inhibits calcium phosphate deposition from supersaturated saliva onto teeth. Our work involved the SN15 peptide, isotopically labeled at L8G12 for NMR studies. The peptide was adsorbed on hydroxyapatite (HAP) crystals, and fluorometry, solid state NMR, constant composition kinetics, and zeta potential experiments were used to observe coverage, structure, kinetics and electrostatic charge respectively. Fluorometry measurements yielded a calibration curve to allow quantification of surface coverage based on the Langmuir model. Results to date include CCK and SSNMR data at monolayer coverage. CCK results suggest that charge interactions, rather than crystal face specific sites, induce bonding. Zeta potential measurements will provide additional support for this theory if they show a significant change in charge for bound vs. free HAP crystals. SSNMR results suggest a largely helical conformation in the region of interest, both on the surface and as a lyophilized powder.

Evaluation of sample preparation techniques to decrease alkali metal interference by inductively coupled plasma optical emission spectrometry in an axial torch position, particularly in a fusion matrix. SARAH LANG (Washington State University, Richland, WA 99352) LMP Thomas (Pacific Northwest National Laboratory, Richland, Washington 99352). SARAH WARRINER (Washington State University, Richland, WA 99352) LMP (MAY-LIN) THOMAS (Pacific Northwest National Laboratory, Richland, WA 99352) .
In research, efficiency and reliability of sample analysis are vital. The inductively coupled plasma optical emission spectrometer (ICP) has the ability to simultaneously analyze multi-analyte samples. However, interferences have been found when analyzing for alkali metals (K, Li, Na) in fused glasses. In this study, two sample preparation parameters have been varied to find a sample preparation technique that will reduce the alkali interference. Test 1 varies the HNO3 concentration from 0% to 4%, and test 2 varies the Cs concentration from 0ppm to 1000ppm. In both tests, the samples were spiked with 0.5ppm of Li, 1.0ppm Na, and 2.5ppm K. In addition, test 1 samples were spiked with 300ppm Cs and test 2 samples were prepared in 2% HNO3 matrix following the current procedure. The results were surprising. Instead of seeing a rising response that leveled off after a particular Cs concentration, the response continued to increase as the concentration increased. The results also showed that the HNO3 concentration was the most stable at 2%. By reviewing previous ICP alkali data, it was discovered that about 200ppm of Na or K are added during the fusion process. The standards used to standardize the ICP instrument, like the samples, are all spiked with only a 300ppm Cs spike. Therefore to accurately standardize the ICP for a glass sample matrix, the standards need to be spiked with a 500ppm Cs spike to increase the standard's salt concentration to match the sample's total salt concentration. Future research could test the effect of salt concentrations at higher levels during ICP analysis to determine if a response limit can be reached.