Using a Systematic Approach To Develop a Chemistry Course

Apr 15, 2013 - some reflections and best practices are presented on how to encourage students to learn actively ... Technology, Zhejiang University (N...
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Using a Systematic Approach To Develop a Chemistry Course Introducing Students to Instrumental Analysis Hao-Yu Shen,*,† Bo Shen,† and Christopher Hardacre‡ †

Ningbo Institute of Technology, Zhejiang University, Ningbo, Zhejiang 315100, China School of Chemistry and Chemical Engineering, Queen’s University Belfast, Belfast BT9 5AG, Northern Ireland, United Kingdom

‡

S Supporting Information *

ABSTRACT: A systematic approach to develop the teaching of instrumental analytical chemistry is discussed, as well as a conceptual framework for organizing and executing lectures and a laboratory course. Three main components are used in this course: theoretical knowledge developed in the classroom, simulations via a virtual laboratory, and practical training via experimentation. Problem-based learning and cooperative-learning methods are applied in both the classroom and laboratory aspects of the course. In addition, some reflections and best practices are presented on how to encourage students to learn actively. Overall, a student-centered environment is proposed that aims to cultivate students’ practical abilities and individual talents.

KEYWORDS: Second-Year Undergraduate, Analytical Chemistry, Collaborative/Cooperative Learning, Problem Solving/Decision Making

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In developing this course, teaching methods have been optimized to meet the requirements of the chemical industry as well as the needs of academic research. A conceptual framework for organizing and executing class and laboratory courses underpins the course. Problem-based learning (PBL) and cooperative learning (CL) methods have been applied in both the class and laboratory courses to provide an environment for students to engage with active learning rather than the passive, conventional teaching approaches that the students often encounter.5−7

nstrumental analytical chemistry is a course commonly offered to undergraduate students majoring in chemistry, chemical engineering, or related specialties.1−4 Typically, the goal of this course is to introduce modern instrumental analysis in chemistry. It is important that students develop individual skills using modern analytical instrumentation and also learn how to ask appropriate questions, how to design experiments, how to critically assess and analyze experimental data, and how to work in a team environment. Instrumental analytical chemistry at Ningbo Institute of Technology, Zhejiang University (NIT) is an undergraduate course with both a lecture (36 h) and a laboratory (18 h) component, and an average class size of 40−70 students. The instruments used for the practical training in the laboratories include UV−vis, FTIR, AAS, GC, HPLC, and GC−MS. However, only two sets of each instrument are available for the practical training in this course, which limits the scope of the training possible given the number of students involved. With the rapid development of increasingly advanced analytical instruments and new techniques and methods, instructors of instrumental analytical chemistry are faced with a dilemma. Which topics should be covered in lecture and on which techniques should the students be trained? A major issue is, therefore, how to balance the increasing content to provide a comprehensive course but with only limited lecture and laboratory hours. In this work, we focus on the ideas and systematic approaches applied to develop the NIT instrumental analytical chemistry course. © XXXX American Chemical Society and Division of Chemical Education, Inc.

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STRATEGIES FOR THE SYSTEMATIC APPROACH TO TEACHING AND LEARNING IN INSTRUMENTAL ANALYTICAL CHEMISTRY

Optimizing the Pedagogical Content

The syllabi of instrumental analysis course are constantly evolving, and not surprisingly, the curriculum reflects the development of both industrial applications and academic research. Instructors of instrumental analysis therefore must judge which topics are core and fundamental and which may be considered as more optional.8 To assess these issues, a survey of papers published from 2001 to 2011 was performed to examine instrumental analytic methods in the literature, and feedback was collected from students who graduated between one and five years ago. The data are summarized in the Supporting Information (S1). In addition, as part of the routine assessment

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of the courses, the students provide feedback every semester and the data since 2003 have been used to assist in the development of the course and is summarized in Supporting Information (S2a and S2b). Figure 1 shows the number of articles about instrumental analytic methods published in ACS journals, in ISI Web of

Scheme 1. Optimization of Teaching the Content of the Instrumental Analysis Course

enhance students’ understanding of the theoretical and practical aspects of course topics. To keep up with the development of new analytic techniques, students are required to read a number of relevant references. In addition, the topics and the content of the PBL have been updated gradually as new instrumental analytic methods have been reported or new analytic standards released. To overcome the issue of limited laboratory time or instrumentation, in 2009 we also introduced a simulation tool via a virtual laboratory. In the virtual laboratory, the students can design their experiments and simulate real-world experimental processes. At the second level (middle of Scheme 1), for advanced methods, such as GC−MS, HPLC−MS, and ICP−MS, a brief introduction to the analytic methods and the instruments used is provided by the teachers either via videos or lectures. The students then search for relevant references about these methods, read at least five references associated with each method and write a critical mini-review individually. At the third level (top of Scheme 1), for newly developed methods, such as EDX, isotope mass spectrometry, and so forth, cooperative learning methods are employed. Students are divided into small groups to study and collect references associated with the analytical methods. Following small-group discussion, students are asked to give a 15 min presentation as a group to the class. Using this framework, conflicts of the increasing diverse analytical subject area and the limited lecture and laboratory hours can be effectively managed. In addition, the students’ learning changes from passive to active. The feedback (Supporting Information S2a and S2b) showed that, before 2005, most students suggested that the teachers increase inclass hours and provide examples of the application of the techniques in daily life. After 2005, when some active learning pedagogical methods such as PBL and CL had been introduced, 90% of students suggested teachers provide more topics related to daily life for PBL. They participated in the PBL of this course actively. Before 2009, >30% of the feedback requested more experimental hours; however, after we introduced simulations via a virtual laboratory, this percentage decreased to 10−15%. The feedback from students also showed that they had been trained in active learning skills. This led to an improvement in these areas: students’ ability to grasp the main aspects of instrumental analytic methods, reading and interpreting journal articles, working effectively with others, analyzing and

Figure 1. Distribution of articles about instrumental analytic methods published in ACS journals, ISI Web of Knowledge, and CNKI from 2001 to 2011.

Knowledge journals, and in China Knowledge Resource Integrated Database (CNKI) journals from 2001 to 2011. The detailed survey results are given in the Supporting Information (S1). The results showed that both in analytical research (Analytical Chemistry in ACS, chemistry analytical in ISI Web of Knowledge, Chinese Journal of Analytical Chemistry in CNKI) and chemical research, in general, more than 80% of the papers were related to optical analysis (containing the term “UV”, “IR”, “AAS”, “ICP”, “NMR”, or “MS” in the title of the article) or chromatography (containing the term “GC”, or “HPLC” in the title of the article). The feedback from 118 students who graduated between 1 and 5 years ago also showed that the more useful instrumental analytic methods they learned in their course with respect to their current employment were related to optical analysis and chromatography. The detailed analysis is summarized in the Supporting Information (S2c). The top three analytic methods were found to be GC (34%), HPLC (27%), and FTIR (22%). On the basis of these surveys, we adjusted the syllabus used and optimized the teaching into three levels, as shown in Scheme 1. At each level, different teaching and learning pedagogical strategies are suggested. As shown in Scheme 1, at the first level (bottom), for the most commonly used methods and techniques, such as UV, IR, AAS, GC, and HPLC, students are asked to study the methods from both the theoretical and experimental perspectives. In this case, both lectures and laboratory training are systematically undertaken. The students obtain a theoretical understanding of the fundamentals of instrumental analysis techniques via lectures; they are also practically trained in the laboratory to understand and undertake sampling as well as the operation of the instruments and data analysis. Since 2005, at this level as well as in lecture, some active learning pedagogical methods have been incorporated both in-class and out-of class (including class discussions, demonstrations, presentations, and PBL) to B

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provide an active learning environment for students. As a consequence, the learning outcomes are not effectively delivered and the feedback from the students is not satisfactory. To improve students’ learning, we have introduced active learning into this course via a combination of lecture on theory and experimental teaching. The major goal is to allow the students to be the masters of their own learning. The overall route to realize this proposal is described in Scheme 3. As shown in Scheme 3, during the lectures, the core content to be mastered in the course is not simply introduced by teachers via a monologue. Some active learning pedagogy, such as PBL, question-based comparison, teamwork, presentations, and student reports, are also undertaken. For instance, before introducing the concept of the chromatography and plate theory, students are asked to recall the procedure of the experiments, namely, extraction of nature pigments from vegetables. During the corresponding experimental training, columns have been used for separation of pigments. By recalling this prior knowledge, not only is the prior and successive knowledge connected effectively, but students will also value knowledge and technology they have been taught previously. This may stimulate their interest and reinforce their self-confidence. During the in-class lecture, current and timely topics, such as the melamine milk powder scandal or the Sudan Red issue, are introduced by teachers to inspire students’ learning experience and link theory with real-life events. Such topics are also given as problem-based learning projects out-of-class, including a problem-solving project lasting the entire semester, and several briefer problem-solving projects. The whole class is also divided into groups with an average size of four to six students per group. Most of the in-class discussion and out-of-class problem solving is performed in these groups. A typical example is given in the Supporting Information (S3). Applying PBL means that students are given relatively little information on how to problem solve. Students must read beyond their textbooks to gain more knowledge by examining other resources, thereby engaging students in active learning and necessitating that they make their own decisions and choices. Cooperative learning involves students working in groups and, therefore, allows them to share knowledge and explain concepts to their peers.9,10 Because it is difficult to provide a tutor for each group, we employed the method described by Woods whereby the groups are empowered to run without a tutor and thus enable the students to learn skills in

interpreting data, oral presentations, and students’ increased confidence and ability to learn difficult concepts. Framework for Organizing and Executing the Course

Instrumental analysis courses seek to introduce students to both the theory and practice of the latest developments in chemical instrumentation. Besides gaining a theoretical understanding of the fundamentals of instrumental analysis techniques via lectures in class, students undoubtedly need to improve their ability to solve real instrumental analytic problems via laboratory training. As well as the experimental work on the instruments, the introduction of the virtual laboratory, described above, allowed the students to develop this aspect. The different sections of the course can be divided into three main parts, theoretical understanding in the classroom, simulations via a virtual laboratory, and practical laboratory training via experimentation. Several kinds of pedagogical methods, such as class discussion, demonstration, presentations, and virtual and laboratory training, have been used to enhance student-centered active learning, as illustrated in Scheme 2. Scheme 2. Framework for Organizing and Executing the Instrumental Analysis Course

Theoretical Understanding in the Classroom

Traditionally in China, teaching and learning of instrumental analytical chemistry are carried out using a didactic approach in which teachers deliver formal lectures to convey knowledge. In this case, the students receive it passively and then are expected to reproduce the information accurately in examinations. This teacher-centered teaching and learning approach may be easy and effective in terms of time for the teachers, yet it does not

Scheme 3. General Pedagogical Methods for Theory Exploration in the Classroom

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access MimicLab by using their student ID number in NIT’s computer center and seats can be booked in advance. Their study hours were logged automatically by the computer center and each student was required to log at least 20 study hours. In the virtual laboratory, MimicLab is incorporated throughout the course in several ways. In addition to using MimicLab for data acquisition, particular emphasis is placed on MimicLab-based simulations. Students can design their own experiments from sample preparation to data analysis to the full simulation of an experiment. Students normally work individually; however, they may also work in pairs if the project is particularly ambitious. A score is given once they finish an entire simulated experiment. The students are asked to finish five such assigned simulated experiments related to FT− IR, GC and GC−MS, HPLC and LC−MS, UV−vis, and AAS. Following completion of the tutorial assignments, students write a report on the experiments undertaken in the virtual laboratory. The virtual laboratory activities account for 20% of the students’ overall course grades.

facilitating group tasks, problem solving, and the learning process.11 They are asked to give a presentation and submit a report for the group project at the end of the semester. The final assessment of the PBL performance is given based on students’ peer assessment: evaluation of the group members, inter-group, 30%; evaluation of the group as a whole, intragroup, 30%; and evaluation by the instructors, 40%. Details are shown in the Supporting Information (S3) in which the rubrics for assessing student performance on the PBL projects were applied by both the instructors and within the peer assessment. The PBL projects account for 30% of the student’s overall course grade while the final examination accounts for 20% of the mark. Simulations via a Virtual Laboratory

As discussed above, available laboratory time or access to the instrumentation is quite limited for the students’ experimental training, so a virtual laboratory was used to overcome this problem. The commercially available software (ISIS 2.0, Beijing East Simnet Company) was used and introduced in 2009, in which 7 main instrumental experiments, that is, UV−vis, AAS, FT−IR, GC, GC−MS, HPLC, and LC−MS, were employed as part of the computer based training. Typical experiments included sample preparation, instrumental operation, calibration curve setup, sample determination, and data analysis. A trial of the software and the operation manual is available from the Simnet Web site.12 As an example of the virtual laboratory, a sample front panel for a GC−MS is shown in Figure 2. By clicking the icons on the

Practical Lab Training via Experimentation

During the laboratory hours, real-world samples are selected for the students to analyze. As much practical training and real problem solving has been provided as possible. Some examples include the determination of the amount of calcium in their own hair, the amount of caffeine in drinks, and the main components of plastic bags. The class is divided into six groups with an average size of 10 students per group. A typical example for laboratory schedule for one group one semester is given in Table 1. A full schedule for laboratory training has been given Table 1. Example Laboratory Schedule for One Semester Week

Experimenta

Labb

2 5 8 11 15 18

Virtual laboratoryMimicLab Determination of caffeine conc. in drinks Analysis of calcium in hair by AAS PAH determination in water by HPLC FTIR of plastic films Determination of benzene, toluene, and ethanol by GC

NE304 NE309 NE308 NE305 NE302 NE307

a

Conducted by Group 1 Students (N = 9). bLab sessions lasted 2.5 h.

in the Supporting Information (S4). The students are asked to submit a prelab report, in which they provide a proposal for the analytic method and instrument selection, a draft experimental procedure, and data record tables. Because of the limited in-lab time slots and number of instruments available, it is still very difficult to carry out in-depth training. To overcome these difficulties, we implemented two strategic methods. First, during the in-lab training, the students work on individual parts of an entire experiment. For example, one student preparing samples, another student running the instrument, a third student doing data analysis, and so forth. By taking turns for each part of an experiment, each student performs the entire lab experiment. Second, we open all the laboratories to the students 8 h a day, five days a week. The students are encouraged to book out-of-lab training slots once they have attended the first practical lab training for a specific instrument. Laboratory technicians, who are the staff in charge of the instrument operation and routine maintenance, take turns as tutors for both in-class and out-of-class practical laboratory training. For those carrying out the same experiment, the students are asked to do a postlab survey to compare their

Figure 2. Front panel for GC−MS in virtual laboratory, MimicLab.

instrument, the anatomy of the instrument is shown step by step. To supplement this information, the student can go back to review either the relevant theoretical or experimental aspects of the course. This dual approach allows the students to develop their study skills. We set up a virtual laboratory, named MimicLab, in NIT’s computer center. In the virtual laboratory, tutorials run in parallel to the traditional course structure of lectures and laboratory. The first laboratory period was used to introduce students to MimicLab. Thereafter, no further laboratory or lecture time is allocated to MimicLab instruction. Students can D

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(2) Harvey, D. Modern Analytical Chemistry; McGraw-Hill: Boston, MA, 2000; Chapter 1. (3) Schaber, P. M.; Dinan, F. J.; Phillips, M., St.; Larson, R.; Pines, H. A.; Larkin, J. E. J. Chem. Educ. 2011, 88, 496−498. (4) Rayson, G. D. J. Chem. Educ. 2004, 81, 1767−1771. (5) Kalivas, J. H. J. Chem. Educ. 2005, 82, 895−897. (6) Wenzel, T. J. Anal. Chem. 2000, 72, 293A−296A. (7) Wright, J. C. J. Chem. Educ. 1996, 73, 827−832. (8) Girard, J. E.; Diamant, C. T. J. Chem. Educ. 2000, 77, 646−648. (9) Lanigan, K. C. J. Chem. Educ. 2008, 85, 138−140. (10) Clougherty, R.; Wells, M. J. Chem. Educ. 2008, 85, 1446−1448. (11) Woods, D. R. Problem-Based Learning: How To Gain the Most from PBL; DR Woods Publishing: Waterdown, Canada, 1994. (12) Simnet Web page. http://www.esst.net.cn/soft/id/33.aspx (accessed Apr 2013). (13) Moore, J. W. J. Chem. Educ. 1999, 76, 725. (14) Dougherty, R. C.; Bowen, C. W.; Berger, T.; Rees, W.; Mellon, E. K.; Pulliam, E. J. Chem. Educ. 1995, 72, 793−797. (15) Smith, M. E.; Hinckley, C. C.; Volk, G. L. J. Chem. Educ. 1991, 68, 413−797. (16) Henderson, D. E. J. Chem. Educ. 2010, 87, 412−415. (17) Grannas, A. M.; Lagalante, A. F. J. Chem. Educ. 2010, 87, 416− 418. (18) Hamstra, D.; Kemsley, J. N.; Murray, D. H.; Randall, D. W. J. Chem. Educ. 2011, 88, 1085−1089. (19) Abraham, M. R. J. Chem. Educ. 2011, 88, 1020−1025. (20) Cartwright, A. J. Chem. Educ. 2010, 87, 1009−1010. (21) Sutheimer, S. J. Chem. Educ. 2008, 85, 231−233. (22) Hinde, R. J.; Kovac, J. J. Chem. Educ. 2001, 78, 93−99. (23) Fahmy, A. F. M.; Lagowski, J. J. J. Chem. Educ. 2003, 80, 1078− 1083. (24) Carpenter, S. R.; McMillan, T. J. Chem. Educ. 2003, 80, 330− 332. (25) Guimera, R.; Uzzi, B.; Spiro, J.; Amaral, L. A. N. Science 2005, 308, 697−702. (26) Pfund, C.; Pribbenow, C. M.; Branchaw, J.; Lauffer, S. M.; Handelsman, J. Science 2006, 311, 473−474. (27) Russell, S. H.; Hancock, M. P.; McCullough, J. Science 2007, 316, 548−549. (28) Jensen, M. B. J. Chem. Educ. 2009, 86, 525−527.

results with the data of the other group members. Students not only go through the whole procedure of the instrumental analytical chemistry, but also gain interest in the course, and confidence. A typical example for AAS experimentation is given in the Supporting Information (S5). The laboratory training activities account for 30% of the students’ overall course grades.

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CONCLUSIONS As advocated by John W. Moore in his editorial, “Learning Is a Do-It-Yourself Activity”,13 we always reflect on what we have done to engage students, how to encourage students to learn and to allow them to bear the responsibility for their own learning. Educators have implemented several means of better engaging their undergraduate students, including active and cooperative learning,14−17 learning communities,18,19 service learning,20,21 cooperative education,22−25 inquiry and problembased learning,26,27 and team projects.23−28 Development of the course instrumental analytical chemistry via a systematic approach, including optimizing the syllabus, setting up a virtual laboratory, and so forth, has been discussed. Three major educational constructs have been used for this course, namely, theoretical understanding in the classroom, simulations via a virtual laboratory, and practical laboratory training via experimentation. This course development effectively manages the conflict of increasing content that needs to be taught and limited lecture and laboratory hours, while also providing a united teaching and learning relationship and thus the formation of a student-centered environment. Although, as shown in the Supporting Information (S2), the student response to development of the instrumental analytical chemistry course has been positive, it needs to be pointed out that the whole teaching and learning process is quite complicated. We have used this systematic approach for the course development and made significant progress in introducing students to modern instrumental analysis. The systematic approach used to develop the course has been a key component and should be used widely.

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ASSOCIATED CONTENT

S Supporting Information *

Data on published papers on instrumental analytic methods; survey instrument; feedback from students postgraduation; student handout; example laboratory protocol. This material is available via the Internet at http://pubs.acs.org.

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS We would like to thank the Ningbo Education Bureau (JD090217, JD100209) and Ningbo Institute of Technology, Zhejiang University (NITJY-201021, NITJY-201217) for the financial support. We would also like to thank C. J. Feng of University of New Mexico for his kind help and suggestions.

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REFERENCES

(1) Danzer, K. Analytical Chemistry Theoretical and Metrological Fundamentals; Springer: Berlin, Heidelberg, 2007; Chapter 1. E

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