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Analytical Chemistry for Nonchemistry Science Majors Valuable lessons for all science majors. John C. Schaumloffel, University of Massachusetts–Dartmouth Mary Kate Donais, Saint Anselm College
NISHAN AKGULIAN
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s trained practicing analytical chemists, many of us would probably prefer to teach students who have a strong desire to learn analytical chemistry. Indeed, well-prepared, motivated students with an interest in analytical chemistry make the educational experience much more rewarding for both parties. However, such students are not always chemistry majors. Within the subject areas of analytical chemistry, some larger institutions offer the traditional quantitative and instrumental analysis courses for chemistry majors in addition to the specialized, one-semester quantitative analysis courses for nonchemistry science majors. Specialized texts are available for the nonmajors (1, 2). Smaller colleges and universities, unfortunately, may not have sufficient student enrollment or staff to offer both types of courses. At the same time, many analytical chemistry faculty in small institutions meet their service requirement by teaching freshman chemistry or analytical chemistry courses that integrate all science majors. These service courses present opportunities to educate large numbers of students and expose them to analytical chemistry. By integrating quantitative analytical chemistry into service courses, particularly with the use of advanced instrumentation, analytical chemists can provide hands-on exposure to techniques that are relevant to students’ professional or postbaccalaureate goals. At the same time, the frequently undesirable “chore” of teaching
service courses can become a rewarding professional experience for the instructor. Advanced analytical chemistry topics can be integrated into upper-level courses in specialized programs such as forensic or environmental chemistry. Depending
on programmatic requirements, some students may not have the opportunity to take a traditional quantitative analysis course before their upper-level courses. Therefore, the laboratory portions of these courses may have to include both
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fundamental and advanced analytical chemistry topics. Such instrumental analysis courses often have varied enrollment, including chemistry, biochemistry, natural science, life science, and environmental science majors. In such a course, the challenge is to integrate aspects of different scientific fields while retaining a fundamental basis in analytical chemistry, so that chemistry majors are not sold short. In designing analytical chemistry courses for nonchemistry majors, one must consider how students may use this knowledge once they leave the collegiate environment. Scientists and nonscientists in all fields rely on data from quantitative analyses to make planning, policy, remediation, and research decisions. With-
ments as soon as possible in the curriculum, greater numbers of nonchemistry science majors are exposed to analytical techniques and methods that represent current practice in the working analytical laboratory. Traditionally, only chemistry majors have gained such experience (12). Unfortunately, students do not always understand the relevance of chemistry (not to mention analytical chemistry) to their professional or educational objectives (13, 14); however, this lack of foresight can be overcome by clarifying the role of chemistry in other fields at the beginning of a course (15, 16). To do this effectively, faculty members should become familiar with the degree requirements for nonchemistry science majors,
By educating this broad audience, analytical chemists in academia can better prepare the general scientific community for the problems they will encounter. out some exposure to analytical chemistry, they will lack the ability to understand the problems analysts may have encountered. Even worse, they may be unable to question the validity of scientific data used in a decision-making process. By educating this broad audience, analytical chemists in academia can better prepare the general scientific community for the problems they will encounter. In attempting to reach this group, we should strive to include context-based curricula, undergraduate research or miniprojects, cooperative and problem-based learning, and the appropriate use of technology (3–8). Using case study investigations of common scenarios encountered via the popular media (televisions, movies, etc.) has also been recognized as an effective means to increase student interest (9, 10). Using modern methods also provides a mechanism to more easily integrate key concepts such as quality control and quality assurance into the laboratory (11) while teaching students mechanisms for data-reduction, recording, and presentation. By introducing advanced instru-
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perhaps through direct discussions with other department faculty. Using a “literary approach” with examples from popular media, film, historical references, etc., has been recently suggested as another successful starting point from which to discuss the capabilities and limitations of various analytical techniques (17). In an informal survey of analytical chemists on a popular discussion list (ANALYSIS-L, http://paml.net/ groupsA/analysis-l.html), subscribers were asked to describe the most important topics or phenomena that nonchemistry scientists should know about analytical chemistry. The most prominent responses indicated that nonchemistry science majors need to understand the difference between detection and quantitation, the effect of the sample matrix on detection limits, the limitations of various methods and techniques, and how analytical results can be interpreted in nonscientific arguments. Additional topics considered important by the survey authors included uncertainty and error analysis, statistical evaluation of
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data, calibration, and quality control. The curriculum at any institution is likely to depend on the needs and level of the student audience, but it should include the fundamental areas just described.
Mechanisms At the University of Massachusetts, the ideal time to introduce nonchemistry students to analytical chemistry is during the freshman sequence. Our course has an enrollment of approximately 200–250 undergraduate biology, medical laboratory science, and engineering majors, representing ~16% of the school’s freshman enrollment. While multiple instructors teach the lecture sections of the course, the supervision of the laboratory curriculum is left to one or two faculty. Nonchemistry science majors will be better educated when instructors introduce instrumental methods during the freshman laboratory and simultaneously relate them to topical material covered in the freshman lecture course. Experiments in this freshman course include the determination of nicotine in cigarette smoke particulates by GC and the determination of sodium in urine by atomic emission spectroscopy (AES). In the former, the context of the laboratory is centered on the public health debate about tobacco use and the role of the chemist in evaluating manufacturers’ claims regarding a product (e.g., milligrams of nicotine/cigarette). The major analytical principles stressed are calibration using a simple comparator method, the use of quality control standards, and chemical extraction. Students pool data from the entire class to evaluate whether an experiment is reproducible from one researcher to another. The Q test determines whether a student’s experimental results are suspect and should be discarded. Vapor pressure, intermolecular forces, chemical equilibrium, and polarity of molecules are the fundamental chemical phenomena that connect the lecture and the laboratory for this experiment. In the sodium in urine experiment, the role of a clinical chemist in evaluating biological samples during a public health study is explored. The preparation of a calibration curve, the evaluation of the linear response of the calibration curve,
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serial dilution, and the importance of understanding the sample matrix encompass the important analytical principles. Connections are made between atomic structure and atomic spectroscopy, the nature of electromagnetic radiation, and the relationship between temperature and ground- versus excited-state electronic structure (using the Boltzmann equation). Primarily because of pedagogical or financial concerns, faculty are often apprehensive when using modern instruments in the introductory sequence (18). However, we have found that the careful selection and presentation of specific instrumental techniques can make their use in the freshman sequence successful and rewarding. Although both freshman chemistry and quantitative analysis offer chances to expose a large number of nonchemistry science majors to analytical chemistry, certain upper-level courses in more specialized fields also provide this opportunity. Forensic and environmental chemistry courses are excellent opportunities to introduce analytical chemistry to nonchemistry science majors and even nonscience majors. The laboratory portions of these courses can be viewed as instrumental analysis designed specifically with the needs of nonchemistry majors in mind. Compared with a traditional instrumental analysis course for chemistry majors, less time is spent detailing how the instruments function. Instead, an emphasis is placed on the use of various instruments to solve problems. Experiments are based on forensic analyses or environmental analyses, but they illustrate key analytical concepts, such as sample preparation and sample matrix issues, calibration, quality control, and uncertainty. By giving students hypothetical scenarios to solve in each experiment, teachers can illustrate important issues such as how to choose an appropriate method for a given problem and how to properly interpret data. By presenting each experiment as a problem to be solved instead of a list of instructions to be followed, students learn to approach laboratory work as problem solving. They also learn the importance of proper data interpretation when they try to solve a problem with the information they gathered in the
lab. The use of a problem-solving laboratory format gives students experiences similar to those they may encounter in their professional lives. Last, teaching a course such as instrumental analysis can be challenging if the enrollment is skewed toward nonchemistry science majors. At Saint Anselm College (Manchester, NH), just as many biochemistry and natural science majors take instrumental analysis as do chemistry majors. How can an instructor address the diverse interests of the class while still illustrating all the desired principles? At Saint Anselm, students propose and design all the experiments while working in small groups (two to three students). Students are strongly encouraged to plan ahead for future experiments so that chemicals, columns, and standards can be ordered. Each experiment turns into a mini-research project, allowing students to critically evaluate published research and results, troubleshoot instruments, manage time, and experience group dynamics. With only one or two instructors for multiple groups working in separate rooms, students are often forced to solve problems with their experiments individually while waiting for an instructor’s help. Groups can usually execute four or five projects in one semester, with no two projects using the same instrument. The number of instruments covered using this approach is less than if a more traditional “one instrument per week” predetermined experiment approach is used. Students tend to choose the more modern instruments in the department and prefer not to include lesser-used techniques, such as electrochemical methods. Examples of recent experiments done by students include the measurement of polyaromatic hydrocarbons in cigarette filters by atomic fluorescence, fragrance analysis by GC/ MS, wine analysis by atomic absorption spectroscopy, and cholesterol determination by absorption spectrophotometry.
to teach nonchemistry majors fundamental analytical chemistry topics and skills. These topics can be introduced during the lecture portions of courses and then demonstrated through hands-on instruction during laboratory sessions. Science majors will be more prepared and better educated when exposed to topics such as calibration, quality control, critical evaluation of data, and measurement uncertainty during their service courses; and, equally important, faculty members will have an opportunity to teach within their specialty. Some faculty may have concerns regarding the thoroughness of the material presented in an analytical chemistry course designed for nonscience majors. However, this should be a secondary concern because such courses are opportunities to expose a greater number of science majors to analytical chemistry.
More prepared, better educated
(13) (14) (15) (16) (17) (18)
Whether through introductory courses such as general chemistry, or more advanced courses such as environmental chemistry, numerous opportunities exist
John C. Schaumloffel is an assistant professor at the University of Massachusetts–Dartmouth. Mary Kate Donais is an assistant professor at Saint Anselm College. Address correspondence to Schaumloffel at the Dept. of Chemistry and Biochemistry, University of Massachusetts–Dartmouth, North Dartmouth, MA 02747 (
[email protected]).
References (1) (2)
(3) (4) (5) (6) (7) (8) (9) (10) (11) (12)
Harris, D. C. Exploring Chemical Analysis; W. H. Freeman and Co.: New York, 1996. Skoog, D. A.; West, D. M.; Holler, F. J. Analytical Chemistry: An Introduction, 6th Ed.; Saunders College Publishing: Philadelphia, PA, 1994. Henry, C. Anal. Chem. 1998, 70, 176 A–177 A. Wenzel, T. J. Anal. Chem. 2000, 72, 293 A–296 A. Ram, P. J. J. Chem. Ed. 1999, 76, 1122–1126. Wenzel, T. J. Anal. Chem. 2000, 72, 547 A–549 A. Dunn, J. G.; Phillips, D. N. J. Chem. Ed. 1998, 75, 866–867. Murray, R. Anal. Chem. 1998, 70, 425 A. Cheng, V. K. W. J. Chem. Ed. 1995, 72, 525–527. Baird, C. J. Chem. Ed. 1995, 72, 684–685. Bell, S. C.; Moore, H. J. Chem. Ed. 1998, 75, 874–877. Kostecka, K.; Lerman, Z.; Angelos, S. J. Chem. Ed. 1996, 73, 565–567. Barker, Jr., G. K. J. Chem. Ed. 2000, 77, 1300. Stout, R. J. Chem. Ed. 2000, 77, 1301–1302. Singh, B. J. Chem. Ed. 1995, 72, 432–434. Singh, B. J. Chem. Ed. 1999, 76, 1219–1220 Lucy, C. J. Chem. Ed. 2000, 77, 459–470. Steehler, J. K. J. Chem. Ed. 1998, 75, 274–275.
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