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Chemical Information Instructor
Andrea Twiss-Brooks
Incorporating Chemical Information Instruction and Environmental Science into the First-Year Organic Chemistry Laboratory
John Crerar Library University of Chicago Chicago, IL 60637
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R. G. Landolt Department of Chemistry, Texas Wesleyan University, Fort Worth, TX 76105;
[email protected] In 1978, a court settlement mandated identification, investigation, and regulation of a series of specific priority pollutants by the United States EPA (1). Among the first compounds to be closely assessed were chlorinated benzenes, prominent because of levels of industrial use as solvents and reaction intermediates. These compounds, similar to PCBs, were known to be resistant to environmental degradation and expected to be subject to bioaccumulation. As part of a team of scientists under EPA contract at Battelle Columbus Laboratories, I conducted an extensive Chemical Abstracts (CA) search to provide background information on chlorinated benzenes. In addition to learning “what to look for” (information on transport and environmental fate as a consequence of chemical and physical properties), this experience demonstrated how the process of “mining nuggets” of information electronically might be employed to sharpen insights into fundamental structure–property relationships in organic chemistry. Since 1993, I successfully have challenged students in organic chemistry lab to conduct cooperative learning investigations (2) of the growing body of published research on the environmental impact of chlorinated benzenes. This activity also was “taken on the road” and shared with faculty and students at 26 primarily undergraduate four-year institutions, as well as at a community college, as phase II of Project UCAIR (3). Based on these experiences, I recommend STN Easy (4) as a channel to CA for undergraduates because it is user-friendly, available through the Internet, and economically attractive when used for classroom instruction (5). Work with students in organic chemistry lab has involved five stages: • Introduction and orientation to chlorinated benzenes and the rationale for their priority pollutant status; • Review of fundamental structural features, nomenclature, and introduction to the CAS registry system; • Orientation to boolean logic with specific emphasis on strategies relating chemistry and the environment; • Hands-on online searching of Chemical Abstracts by teams of students using STN Easy; and • Composition of a report by teams of students, targeting the potential impact of “chlorinated benzenes in the ocean environment”.
Active participation by students is emphasized throughout. Students, working in cooperative learning groups (task
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forces) of 3–6, are first asked to determine the number (12) and identity of all members of the candidate priority pollutant category (mono-, di-, tri-. tetra-, penta-, and hexachlorobenzene isomers), followed by identification of a Chemical Abstract Service (CAS) registry number for each compound (6, 7). Following an orientation to information relevant to environmental policy-making (sources, transport, fate, and toxicity, etc.), student task forces are charged with devising search strategies, conducting online searches, and collating results in a report “suitable for the (United States) EPA”. Limiting the project scope to ocean systems serves to provide focus for search strategy development within a meaningful environmental context. Students require minimal instruction to use the STN Easy search engine’s “Advanced Search” option effectively. Emphasis should be given to (i) the utility of CAS registry numbers, (ii) use of truncation symbols (? or *) for search terms on the SEARCH PAGE, (iii) the “no extra cost” as well as pedagogical benefits of the “refine your search” function built into the RESULTS PAGE, and (iv) the benefit of critical screening of article titles before viewing abstracts. Students should be challenged to anticipate that authors of research articles might employ alternative descriptors, such as “sea” or “marine” for the ocean environment. Individuals assigned to one segment of the problem should be cautioned regarding tunnel vision and reminded to be alert for information about which other team members should be aware. Usually, a single three-hour lab period is sufficient to provide instruction and for students to carry out online searching. Should time be more restricted, searching may be limited to publications appearing in the last 2–5 years. It has proved most beneficial for members of student groups jointly to contribute to and evaluate group reports, which are usually turned in after one week. Reports should include a clear problem statement, a description of the specific search activities employed, a summary of the results found, and analysis of how well the problem was solved. Students with a background in fundamentals of aromatic structure can make good use of this experience. The activity has been remarkably cost effective, with cost per student averaging approximately $5. As of this writing it is possible to obtain convenient daytime classroom access to Chemical Abstracts using the Academic Discount Program. The CAS customer service office should be consulted for general information, account set up, and technical assistance (8).
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Acknowledgments Project UCAIR was supported by Special Project Grants from the Welch Foundation, the Camille and Henry Dreyfus Foundation, and Research Corporation. Participation in planning and execution of UCAIR by university librarians Joe McCord (University of Houston, Clear Lake), Elizabeth Snapp (Texas Women’s University), and Arleen Somerville (University of Rochester) and professors Michael Doyle (University of Maryland) and Joe Lagowski (The University of Texas, Austin) is sincerely appreciated. W
Supplemental Material
A Microsoft PowerPoint presentation, STN Easy screen shots containing hints for effectiveness, and a student team report are available in this issue of JCE Online. Literature Cited 1. Keith, L. H.; Tellfard, U. A. Env. Sci. Tech. 1979, 13, 416– 423.
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2. Concerning active learning in organic chemistry, see: Carpenter, Suzanne; McMillan, Tim. J. Chem. Educ. 2003, 80, 330, and references cited therein. 3. UCAIR Web site. http://department.txwes.edu/che/rlandolt/ ucair2003.html (accessed Nov 2005). 4. STN Easy Home Page. http://stneasy.cas.org (accessed Nov 2005). 5. CAS Academic Program for North and Central America. http:/ /cas.org/Support/acus.pdf (accessed Nov 2005). 6. Through 2005, the hardcopy catalog, Aldrich Handbook of Fine Chemicals and Laboratory Equipment, includes all but the 1,2,3,5-tetrachloro-isomer. The registry number for the latter may be located with the others at the main Web site: http:// www.sigmaaldrich.com (accessed Nov 2005) as well as by using Internet search engines such as Google. 7. A reviewer usefully suggests employing the Hazardous Substances Databank, HSDB, found at the TOXNET Web site, http://toxnet.nlm.nih.gov (accessed Nov 2005), where the ChemIDplus component may be used to identify Registry Numbers. 8. CAS Customer Care Home Page. http://www.cas.org/Support/ custserv.html (accessed Nov 2005).
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