Education
Instrumental Analysis at the
University of Kansas: An Experiment in Problem-Based Learning
IMAGES® COPYRIGHT 1999 KANSAS UNIVERSITY OFFICE OF UNIVERSITY RELATIONS
Problem-based learning in analytical chemistry is not a new concept. In the mid-1960s, HerStudents work in groups bert Laitinen focused undergraduate analytical chemistry solve real-world problems curriculum development at the University of Kansas on probbeen directed toward team approaches to lem solving. Shortly after becoming editor of Analytical Chemistry, he wrote: "Analysis solving analytical problems—the role-playing approach developed by John Walters at of a sample is not the true aim of analytical chemistry the real purpose of the analy- St. Olaf College (2) and the cooperative learning experiment of Tom Wenzel at sis is to solve a problem" (1). This Bates College (3). Like these approaches, a labeled the "analytical approach" and major goal of our problem-based learning has been the subject of many articles course is to have students solve a problem the past 20 years Two recent efforts have rather than just perform an analysis. Nearly eight years ago, representatives George S. Wilson of the pharmaceutical industry asked Marc R. Anderson whether we would be willing to set up a Craig E. Lunte curriculum to train B.S.-level scientists. University of Kansas
Because problem solving was of special interest, we decided to implement the concept broadly to in our undergraduate analytical courses rather than create a specific curriculum for B.S.- or M.S.level scientists. This effort now coincides with a departmental effort to introduce inquiry and team approaches to the identification and solution of chemical problems. To solve problems, students must have a "tool box" (4) of techniques and concepts that can be applied to any problem. We do not assume that the tool box is "full", either at the beginning or at the end of the course. Our two-semester sequence in analytical chemistry, usually taken in the student's junior year, consists of a lecture and laboratory course in each semester. Some
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Education students will be enrolled in a physical chemistry lecture and laboratory concurrently, and all students will have taken two semesters of organic chemistry. Tools specifically oriented toward analytical chemistry are provided in the fall semester in the Introduction to Analytical Chemistry course. Originally the classic "Quantitative Analysis" lecture and laboratory course,
uate instructional use. We wanted a reasonable choice of techniques available so that students could select the ones most appropriate for each task. A narrower selection of equipment could limit the scope of problems that might be tackled, but it should not diminish the value of the experience if the problems are properly chosen. Equipment such as NMR, mass spectrometers, and confocal or scanning electron microscopes are serviced through the usual support facilities. Course format The students are divided into three- to five-member teams, which constitute the analytical
these courses now seek to acquaint students with analytical methods by focusing on the significance of analytical measurements IMAGES® COPYRIGHT 1999 KANSAS UNIVERSITY OFFICE OF UNIVERSITY RELATIONS and why a particular approach is most appropriate. Thus, group of a real-world enterprise, such as a students may perform an analysis by a varigovernment laboratory, a consulting firm, ety of methods: complexometric titration or a chemical or pharmaceutical company. atomic absorption spectroscopy or ion The analytical team is presented with a chromatography for example Because problem for which they must find a soluthese biochemistry education and B A tion. They can consult with their group chemistry majors do not take instrumental leader (one of the teaching assistants analysis we have extensivelv revised the [TAs] in the course), with an internal confirst course to cover the basic nrincinles of sultant (the faculty member teaching the electrochemistry spectrosconv and sepacourse or other faculty within the chemisrations This strateev enhances the tool box try department or elsewhere on campus), for those proceeding to the probor with external consultants. The latter are lem based learninff course in the sprinp Rpfore embarkinp- on a substantially revised curriculum, we devoted about five years to acquiring, through industrial, uniJ XT 4i
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versify, and National Science Foundation (Instrumentation and Laboratory Improvement) support, state-of-the-art equipment that is allocated specifically for undergrad-
persons in industry government or other academic institutions who volunteer their time to provide students with input in perby e-mail telephone or fax It has proven remarkably easy to find suitable problems for students to solve and then enlist support from consultants and others in the form of information, materi-
678 A Analytical Chemistry News & Features, October 1, 1999
als, and, in some cases, borrowed or accessible equipment. The appeal is that students can actually learn about real-world problem solving. Typically, 20 students enroll in the course each semester. Thus, the laboratory course emphasizes problem solving and technical skills, and the companion lecture course provides a survey of the fundamentals of the instrumental methods used in the laboratory, as well as other instrumental methods. At the beginning of the semester, the students are given a list of the companies to which they may apply for employment and a general description of their activities. The application form asks for information about the student's background, previous experience, and plans for the future (industry, medical school, graduate school, MBA, etc.). On the basis of this information and scheduling considerations, we try to put students in the group of their preference without placing all the strong students in The previous job experience of particular students valuable and they quickly position of importance within their Because of its late position in the chemistry curriculum, chemical and instrumental concepts can be integrated. Thus, we feel free to draw on previous experience in organic or biological chemistry, or molecular biology. Although students are increasingly familiar with the Internet, they are not especially proficient at accessing databases and other information useful to chemists, nor have they had much experience in problem solving, working as a member of a team, or communicating orally or in writing. Consequently these activities form the basis for job perforevaluations Perhaps not surprisingly, one of the most difficult processes for students is defining the problem. For example, we posed the problem of dead fish along the banks of a local river (See p 681 A)) The students' first reaction was to suggest analyzing the river water for everything possible until they realized that neither time nor available resources would permit such an approach. The first month of the course is devoted to defining the problem, choosing the appropriate analytical methods, including sampling and sample preparation, 3.SS3.V Vslidcl"
tion, and regulatory issues (EPA, FDA, OSHA), as well as the projected cost of materials, equipment use, and labor. This information is contained in a project proposal, prepared according to specific guidelines, which is presented and approved by management before any laboratory work commences. We give students as much latitude as possible in choosing the approach, even if, in some cases, it might not work exactly as envisioned. The importance of maintaining proper records and a laboratory notebook is emphasized. The first month of the course is also devoted to gaining further experience with analytical instrumentation especially that which will be used in team
to the list as representative heavy metals. Next, it was decided that soil samples would provide the means for assessment. A sampling scheme, consistent with U.S. Environmental Protection Agency (EPA) guidelines, was devised to obtain soil core samples from a regular grid spanning the 10-acre area. Karmie Galle, a volunteer consultant from the Kansas Geological Survey, provided actual soil samples from the grid points specified by the students. By searching the Internet, the students discovered that these samples were taken from a Superfund site and they discussed sampling issues with the site m3.iict£rer
projects About eip*ht weeks is devoted to obtaining with the remainder of the time allocated to Dreoaring the nroject pronosal a nrogress renort and the final rpnorts The
analytical approach is illustrated by two problem examples. Environmental assessment: An industrial park in Leadville, KS The Problem: The town nf Leadville, KS (a real place with a fictitious name), wishes to locate an industrial park on the site of a former lead mine and smelter. An environmental remediation project has been completed. Has the site been sufficiently cleaned to render it safe for a new use? The students, now employees of the Kansas Health and Environmental Protection Association (KHEPA), a consulting firm, were presented with a map of the 10acre area in question. The map indicated the approximate site of the smelter, the mine tailings pile, the railroad siding, and other buildings associated with the mining operation. The first task was to define "safe" and develop criteria based on analytical results, which would answer the question definitively. Because the end results needed to be part of an environmental impact statement, attention was focused on what analytes needed to be measured and by what method. Obviously, lead would have to be measured; cadmium and zinc were added
The KHEPA team observed a significant heavy metal concentration variation within the site, which was in a pattern consistent with the presumed previous use. The levels of lead, cadmium, and zinc at the site were also higher than those levels observed in typical Leadville-area baseline soil. The precision of the measurements, as evaluated using NIST standards, was not as good as hoped, suggesting that more careful control of the sample preparation conditions would be needed. Safety of a pharmaceutical excipient: Tris Tris (2-amino-2-hydroxymethyl-1,3-propanediol) is a mildly alkaline compound often used in the formulation of acid-functional nonsteroidal anti-inflammatory drugs, such as ketorolac, diflunisal, and
Other matters considered during the planning period included establishing a modified standard method for the acid digestion of soil (EPA Method 3050), following EPA guidelines for quality control in the preparation of calibration curves, and IMAGESC ) COPYRIGHT 1999 KANSAS UNIVERSITY OFFICE OF UNIVERSITY RELATIONS validating the method with National Institute for Standards and Technaproxen. The Food and Drug Administranology (NIST) standard soil samples. The tion (FDA) has raised concerns that, at team understood that interpreting the rehigh doses, this excipient may not be propsults would require knowing the allowable erly eliminated through the kidneys in sublevels of heavy metals in the soil, while also jects with impaired renal function. Methodtaking into account that levels of heavy ology must be developed to address this metals might be naturally elevated in an issue. rich in these toxic materials The bioanalytical group of Lazarus In performing the cost analysis, the Pharmaceuticals is charged with the reteam discovered that the number of samsponsibility of developing an analytical ples had to be substantially reduced bemethod for the analysis of Tris, keeping in cause of resource limitations. The team mind that the method will be used to deternoted that the heavy metal-free nitric acid mine levels of the analyte in urine. Moreused for digestion was a major reagent cost. over, the renal clearance of Tris should be 6
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Education studied in animal models, such as rats. Because the Tris clearance studies were to be carried out on rats, a properly documented protocol was developed and submitted to the University's Institutional Animal Care and Use Committee. One member of the team was designated to obtain the necessary certification for the use of rats. During the planning period, it became evident that the sample matrix (urine) was going to significantly complicate analysis. Discussions with the consultant, Bogdan K. Matuszewski of Merck, Sharp, and Dohme, established that Tris would have to be derivatized to facilitate fluorescence detection at the levels expected in the sample. This would require, in turn, sufficient reagent to react not only with the primary amine functions of the Tris, but also with the primary amine functions of the many other amines present in the sample matrix In view of this complication the relative merits of prepostcolumn derivatization weighed The method chosen for the fluorescence measurement of Tris required precolumn derivatization, and, because of the large amount of reagent added, a large peak was observed that partially overlapped with the analyte peak. This posed problems at low concentrations of Tris but not at high concentrations. Final report
At the end of the semester, the team's final report is due in three formats—a written report that addresses the concerns of the client, a poster to be presented at a scientific meeting, and an oral presentation in the same milieu. Each year, we convene the International Symposium on Instrumental Analysis Laboratory to which the students and the chemistry department faculty are invited. A poster session precedes the oral presentations. The various reports are prepared according to specified guidelines and they are evaluated by the leaders according to criteria provided in advance to the students Students take turns assuming responsibility for various aspects of the presentation process Job performance evaluation
It is made clear to the students at the beginning of the semester that their grades 680 A
will be based equally on individual and group performance. The criteria include demonstration of technical knowledge and its application, quality of laboratory work and data interpretation, ability to function in a team framework, individual contributions to the project, quality of written and oral reports, leadership, attitude toward work, and attendance. A monthly written evaluation is given to each student by the group leader. The students' performance is discussed witii them to be sure that they understand the basis for the evaluation.
The extent to which students become engaged in the process, argue about how to approach the problem, and develop positive attitudes toward their abilities makes the course enormously rewarding. The group leader meets with the group at least weekly. "Middle management" (the faculty in charge) and/or the consultants interact with the team biweekly or more often at critical stages. Efforts are made to ensure that all of the group members frequently have an opportunity to contribute and demonstrate their job skills during the project. In this way, we hope to avoid the problem of only several students providing the essential input, while the others simply do what they told. The course instructor usually serves as one of the group leaders and meets with the TAs each week. Scientific and technical matters and personnel issues such as overly bossy team members, power struggles, and nonperforming participants are discussed. Assessment
Anyone who has attempted to teach an instrumental analysis course realizes that it is impossible to cover all the important techniques, especially in the laboratory. Our conclusion is that it is better to learn sev-
Analytical Chemistry News & Features, October 1, 1999
eral techniques in-depth rather than many superficially. Developing a strategy for solving a team's analytical problem requires time and careful thought. There is much discussion and debate about the best way to solve the problem. The team will probably use two or three analytical methods during the semester, including HPLC, GC/ MS, atomic absorption, ion chromatography, NMR, UV-vis, fluorescence, and FT-IR spectroscopy. During the planning phase, tasks must be divided up because there is far too much work to be done by one person. We let the students choose their own leaders. Thus, role playing does occur, but it is not as formal as in the Walters approach (2). The group assigns the various tasks: literature searches of possible analytical methods, familiarization with the instruments to be used, determination of regulatory issues, cost estimates, and project proposal writing. The consultants provided effective advice when it was specifically solicited and they were also effective in pointing out specialized aspects of sampling sample preparation and assay validation During the implementation phase, the job responsibilities shift, and it quickly becomes evident that careful planning and coordination are essential. The laboratory is made available from 8:00 a.m. to 5:00 p.m. each weekday and at prearranged times on the weekend so that group leaders are available. Thus, although a group is assigned a nominal laboratory period, it is free to plan its own work schedule. As the semester progresses, a group's confidence builds as members realize that they probably know more about their problem than most faculty and fellow students. Students sometimes complain that the course is too much work for the credit received. However, in general, they admit that, with proper time management and good teamwork, the task is not really burdensome. The extent to which students become engaged in the process, argue among themselves about how to approach the problem, and develop positive attitudes toward their own abilities is so impressive that, even for die faculty, who also have to expend more effort, the course is enormously rewarding.
The superior student often has misgivings about a course that has no formal exams and where half of the final grade will be determined by team performance. Including criteria such as leadership and communication skills in a performance evaluation does not seem appropriate to them. However, at the end of the course, these same students reflect positively on how they developed better communication and interpersonal skills. The monthly evaluations help to develop good rapport between the student and the group leader and facilitate an understanding of the
times both. It has been our experience, echoed by others who have tried similar approaches, that many people within and outside the university become enthusiastic participants in this kind of experiment provided it does not put too much of a burden on their time. The problems are not "checked out" in advance, so the students understand that even the faculty members do not know the outcome. Problems can be used more than once, and we have experimented with giving the new group the final report of their predecessors to be used as the basis for further investigation
TA performance is evaluated by the university in the usual way, but it is also evaluated de facto as the performance of the team that they lead is also assessed. Thus, although the TA job is demanding, it is not difficult to get volunteers because the future value of the experience is obvious. Students seem most intrigued by the study of "real" problems, and, where possible, the use of "real" samples. Some examples of "real" problems and samples are given below. This realism is significantly enhanced by the consultants, who provide samples, or advice, and some-
As problem-based learning becomes more firmly established at lower levels of the undergraduate curriculum, we may be able to focus less on the process and more on the problem solving itself. Students gain deeper insight into analytical problems as they encourage and motivate each other. They come to think of the faculty and TAs as collaborators, and they are enthusiastic about the opportunity to improve their communication and interpersonal skills. Our experience so far has been very encouraging and the course provides a rich learning experience for the TAs and faculty as well
Projects Kansas Health and Environmental Protection Association Investigation of a fish kill on the Kansas River. Problem: At a certain section of the river, dead fish are observed. It is established that the fish are not diseased. What toxic substance(s) killed the fish, and what was the source? Issues: Identification of key analytes, sampling, sample preparation, assay validation, government regulations, toxicology, cost.
Securitech, Inc. Rapid assessment of chemical warfare agents. Problem: A site is deemed vulnerable to attack by thiol-containing chemical agents. A rapid (2-min) detection method is needed, which can identify the agent(s) and their concentrations at the 10-ppb level or higher.
Issues: Identification of key analytes sampling, sample preparation, instrumentation development, assay validation, toxicology, costs.
Payton Upland (Pay Up) Pharmaceuticals, Inc. Monitoring a fermentation process. Problem: Validation of an analytical method for pseudoephedrine in a fermentation extract (chiral separation). Issues: Sample preparation, assay validation, government regulations.
S. Holmes and Associates Identifying the make of an automobile based on the properties of the car bumper. Problem: A state investigative agency would like to know whether physical or chemical properties of a car bumper could be used as forensic evidence in identifying the car make.
References (1) Laitinen, H. h-Ana/. Chem. .966,38, 1441. (2) Walters, J. P. Anal. Chem. 1991, 63,977 A985 A; 1077 A-1087 A 1179 9-1191A (3) Wenzel.T. Anal. Chem. 1198, 70, 790 A795 A. (4) libby, R. In Curricular Developments in the Analytical Sciences: A Report from the Workshops (October 28-30,1996, and March 13-15,1997); National Science Foundation Directorate of Education and Human Resources/Division of Undergraduate Education and Division of Chemistry: Arlington, VA 1997; pp 38-39. George S. Wilson is professor of chemistry and pharmaceutical chemistry at the University of Kansas. His researcc interests include biosensors, bioelectrochemistry, ana the application of biological recognition to bioanalysis. Marc R. Anderson is currently a Ph.D. candidattea the University ofKansas, working undee the direction ofTedKuwana. His research interests include chemical instrumentation and the application of electrochemical techniques to trace analysis. Craig E. Lunte is a professor or chemistry at the University ofKansas. His research interests include the real-time monitoring of drug pharmacokinetics using microdialysis with electrochemical fl,orescesce and MS detection Addresssorrespondence about this article tt Wilson nt Department of Chemistry University ofKansas Lawrence KS 66045 (
[email protected] ukans edu)
Issues: Sampling, sample preparation, instrumentation development, statistical analysis of data, generation of data understandable to a jury.
INTELIigent Analysis, Inc. Quality control assessment procedures for the production of computer hard drives. Problem: Are the protective and lubrication layers of a hard drive of uniform composition and thickness (resolution on a nanometer scale)? Issues: Sampling, sample preparation, standards, identification of key analytes.
Nectar of the Gods Consulting Monitoring of microbrewery beer quality. Problem: What is the active component in "skunky" beer, and under what conditions does it form? Issues: Identification of key analytes, sample preparation, synthesis of analyte.
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