Example Themes That Have Been Used

Described below are several themes and related student-selected projects recently implemented at Butler University. Each description includes the general structure of the course, the experiments performed by the students, the process by which the experiments were determined, and the outcomes from the student work.

Bioanalytical Chemistry

The bioanalytical-themed module was the first team-taught module at Butler. The two professors developed much structure for the course, including grading rubrics, writing style guidelines, and even lists of relevant literature references. This structure enabled two professors with different classroom teaching styles to adopt a uniform set of expectations for both the faculty and the students. In the end, this level of structure benefitted the students, who still had room to explore and develop their own ideas.

The lab work in the bioanalytical theme was implemented using 3 distinct projects, with each successive project providing students with more freedom and discovery. The first project involved a simple fluorescence experiment where students employed a Biotective Green reagent cocktail to quantify biotin in vitamin samples. Much of the student input was focused on adapting the reagent instructions in order to obtain meaningful data. The second project involved simultaneous implementation of two different methods for assaying vitamin C. Students were divided into two groups, and each group selected a different assay method from provided literature sources. Group 1 selected an electrochemical method, using a modified carbon paste electrode to determine ascorbic acid concentration. Group 2 adapted a chromatographic method to study the vitamin C. At the end of the experiment, the two groups shared data and were able to compare the two methods for accuracy and precision. In the final project, the class researched and developed a biosensor for analysis of glucose. This project was selected by the students with some guidance from the instructors. The student-built potentiometric sensor was compared to a commercially available blood glucose detector for accuracy. Unfortunately, the success of the project was limited due to the cost of materials and time. However, students were able to explain their attempts toward achieving their goal.

Forensic Chemistry

The forensic chemistry module has been implemented three separate times at Butler, with each implementation following a different structure.

In the first implementation, students were allowed to select three different projects to study over the course of the semester. The students selected (1) the determination of ethanol in breath by FTIR, (2) analysis of arson debris for accelerants by GCMS, and (3) determination of an analyte in a complex matrix (urine) by ICP-OES. Students worked to validate each analytical method using standards and then attempted to create mock crime scene samples which could be analyzed. The most successful of these projects was the arson analysis. The students burned wood samples soaked in different accelerants and were able to use the GC pattern of peaks to match an unknown accelerant to a standard. The urine project was the most inconclusive, though the project did involve a community partner from a local test-strip manufacturing company. All three posters were presented to the department in poster format.

Learning from the past, the second implementation was more focused and involved a forensic chemist from another local university. With his expertise, we developed a set of evidence from the scene of a crime. The scenario is provided in Appendix B. The evidence included arson samples, actual pipe bomb fragments, contrived drug samples and powder, and ink from a note and several pens taken from potential suspects. With this suite of evidence, students were instructed to divide and identify methods published in the literature suitable for analysis of these types of samples. Once they identified methods, the groups reconvened and reported their findings. By the end of week two, students had selected several methods to study their samples: LCMS, GCMS, FTIR, and TLC. The group divided into teams and each team had primary responsibility for a particular project, but also had secondary responsibility to review and discuss another project. In this way, each student was exposed to multiple aspects of the project. Appendix E depicts sample results from this project.

The latest implementation of the forensic chemistry module provided students with a list of potential topics to study, and the students were expected to research and select one project on which to focus their efforts. While the instructor made an attempt to guide the group toward analysis of inks and dyes, the group chose analysis of gunshot residue (GSR). The goal of their research was to link the GSR on a sample of cloth back to the GSR found in a bullet casing. Initial work focused on the validation of an ion chromatograph and an ICP-MS for various metals and ions common to GSR. However, validation also focused on less common ingredients in the hope that some “fingerprint” might be found specific to a particular ammunition manufacturer. Once validation was completed, students wrote a formal document describing their procedure and the results, focusing on statistical analysis of and confidence in their data. The last several weeks of the semester were then dedicated to the analysis of real samples. Students collected their own samples with the help of a local shooting range and performed analysis. Casing analysis was somewhat simple, but analysis of the cloth proved more difficult. The students realized a flaw in their collection method (and the fact that the range was busy and much GSR was present in the air) and so the attempt to quantitatively match casing to cloth proved inconclusive.

Molecular Spectroscopy and Art

In this module, students were provided with the theme of art and art conservation. Because of the nature of the topic, and the difficulty in collecting samples, specific analytes and questions were presented to the students. The questions were developed with the help of the staff scientist at the Indianapolis Museum of Art. Problem 1 introduced students to the issues surrounding the degradation of smalt pigments. Specifically, smalt “fades” over time from a brilliant blue color to a pink/brown. Studies show that the potassium leaches from the smalt (potash glass) and the coordination of the cobalt changes from tetrahedral to octahedral. This change in coordination leads to the color change. Students were asked to develop and implement a project that would contribute to the understanding of this process. Limited by time and equipment, students chose to examine two variables: rate of degradation as a function of composition and as a function of particle size. Using a small furnace, students formulated different cobalt glass samples and then ground and sifted them to create a uniform size. Analysis was accomplished by artificially fading the samples through exposure to an aqueous environment at an elevated temperature. Within one week, samples were degraded. Problem 2 centered on brilliant but fugitive eosin-based pink pigments used by van Gogh and others in the late 1800s. Students chose to examine rate of decomposition of the pigment as a function of atmosphere (N₂ vs. air), and determine the identity of any decomposition products (especially brominated products) in the gas phase. Fading occurred in a light chamber, and much of the fading occurred within the first few hours of exposure in the light chamber. Analysis of the materials was accomplished using the instrumentation available at the Indianapolis Museum of Art (SEM, reflectance spectrometer, optical microscope) and the instrumentation available at Butler (GCMS, FTIR). While preparation and fading occurred as expected, data from the spectroscopic analysis did not provide insight into the mechanism of fading for either of the two pigments. However, students were able to make two claims: (1) The smaller smalt particles acted as sacrificial particles, completely fading before the larger particles. Therefore, better control of the particle size might contribute to a better understanding of the decomposition system. (2) The amount of eosin pigment mixed into a paint binder is so small that any decomposition products are present in too small of an amount for conventional analysis. A larger paint sample or larger concentration of eosin pigment is needed for a quantitative study of the decomposition products.

Other themes specific to faculty interest have also been implemented at Butler University. Selection of a theme should be tailored to faculty and student interests.