Chemical Education Today

274 Journal of Chemical Education • Vol. 75 No. 3 March 1998 • JChemEd.chem.wisc.edu

Should Advanced Instruments Be Usedin Introductory Courses?

by Jack K. Steehler

Recently I attended a na-tional gathering of college/university chemical educatorswhere the topic of appropri-ate use of instrumentationwas under discussion. Basedon personal experience, I knewthat the answer to the titlequestion was “Yes, of course!”After all, hasn’t this Journalpublished a number of articleson this very topic (1–5)? Tomy surprise I heard a majority

of the group at the recent meeting expressing serious doubtsabout any use of instrumentation (beyond the level of pHmeters or the simplest visible spectrometer) in introductorylaboratories. What a shock! Apparently there is still real re-sistance to widespread adoption of this practice, necessitat-ing further open discussion of the issues involved.

I work at an institution where instruments are usedeverywhere. Our first-year science majors have hands-onexposure to almost all major instrumentation in the year-longsequence (FT-NMR, HPLC, UV–vis, GC/MS, AA, FTIR).Our large-enrollment liberal arts chemistry course has studentsdoing FT-NMR on aspirin samples they synthesize, crimesolving by HPLC, and using AA for water analysis. The dis-parity between my own experience and the majority view-point at the recent gathering caused me to reflect carefullyon this question and prompted this essay. The bottom linewill be a conclusion that instruments can and should bewidely used at the introductory level, but both sides of thequestion will be explored.

First of all, let’s explore the driving forces encouraginguse of instrumentation at the introductory level. A brief listof those forces includes:

• Introductory courses reach the greatest number of stu-dents, increasing the educational impact. Typically thenumber of students who would eventually be exposedto instrumentation in upper level instrumental analy-sis courses is only 10% of the number at the intro-ductory level. For many students the introductorycourse is their only chance to experience an impor-tant part of modern laboratory science.

• Modern science makes extensive use of instrumentalmethods, and students should be exposed to that reality.

• Student expectations of science include modern tech-niques, and student responses are improved when thoseexpectations are met.

• Today’s students need to see connections to their livesand experiences. Modern instruments match up wellwith experiments with significant real-world flavor,such as crime scenarios or environmental investigations.

Two statements form the heart of this list. First, weshould teach students chemistry that is closely related to howthe discipline is currently practiced. Surely no one will arguethat students do not need to understand modern instrumentalmethods! The second core idea is that today’s students re-spond best to course content that they perceive to be relevant.The standard practice of 20 years ago of expecting studentsto embrace a set of core concepts simply because they arestated to be core concepts is no longer effective (if it ever waseffective for more than the elite students). Beyond this ideaof student motivation, we should recognize the benefits ofusing a variety of teaching methods. Modern instrumentationoffers a learning experience thatcomplements both classroominstruction and traditional labo-ratory experiences. Instrumentsoffer not only exposure to tech-nology, but a visual approach tounderstanding data. Graphicalpresentation of recorded data isalmost instantaneous, allowingclose linkage between the labwork generating the data and theinterpretation of those data. These ideas describe real benefitsof using instruments in the curriculum.

However, we also want to define the doubts and con-cerns that exist about such laboratory programs. Again, a brieflisting is appropriate.

• Sufficient instrumentation cannot be provided to servethe number of students at the introductory level. Singlecopies of instruments cannot serve a full class of students.

• Use of advanced instruments by introductory studentswill lead to significant problems with broken equip-ment. Upkeep and repairs are too expensive.

• Black box instrumentation distances the student labexperience from the core principles of introductorychemistry courses. The hands-on flavor of chemistryin a beaker is essential.

There are two concerns being expressed here. One concernincludes a range of practical concerns—sufficient instrumentavailability, sufficient durability, sufficient support funds. Thesecond concern is the pedagogical question of whether instru-mentation teaches what needs to be taught.

One answer to such questions is to point out the successmany schools have had with instructional use at introductorylevels. In the experience of my own institution, the practicalconcerns can all be handled successfully.

The entry-level problem is acquiring instruments in thefirst place. Obviously few institutions can purchase a fullrange of instructional instruments solely with internal funds.External grants are available to assist with such purchases.

Commentary

To my surprise I heard

a majority of the group

at the recent meeting

expressing serious

doubts about any use

of instrumentation…

in introductory

laboratories.

Instruments offer not

only exposure to

technology, but a

visual approach to

understanding data.

Chemical Education Today

JChemEd.chem.wisc.edu • Vol. 75 No. 3 March 1998 • Journal of Chemical Education 275

However, you must apply in order to be funded!! That initialbarrier, convincing yourself to apply, is the largest hurdle toovercome. And if initial applications are turned down, getsome constructive feedback and try again. Our chemistrydepartment has the instruments it has primarily owing to awillingness to seek external funding. Almost all of our instru-ments have involved external grants,with appropriate internal matchingfunds.

What about the durabilityquestion? We have had extremelylow breakage problems. In ourmore than ten-year experiencewith FTIR, GC, HPLC, FT-NMR, UV–vis, and AA usage inintroductory courses, we have had to deal with only two in-jection syringes that needed replacement (one GC and oneHPLC) owing to student misuse, one broken quartz UV cu-vette (broken in an advanced course, not first year), and onlyone broken NMR tube in the magnet. Students have causedzero problems for the FTIR and AA instruments. We havealso found that expenses for both ongoing purchase of con-sumable supplies and for occasional needed instrument re-pairs have been quite manageable, although buying cryogens forthe NMR is a large expenditure.

Next, let’s consider the question of work load per instru-ment. Our institution has only one of each major instrument(except GC: we have two GCs and one GC/MS). Yet we havebeen able to use these instruments extensively without longwaits in line. Scheduling is the key, along with experimentaldesign that rotates students through several activities, reducingpeak demand on instruments. For example, in our crime lab,students rotate through four stations—sample preparation,GC, TLC, and HPLC. Using more instruments actually helpsease scheduling problems. We also define instrument conditionsto maximize efficiency. For example, a typical IR takes 2–3minutes, a UV–vis spectrum takes 2–3 minutes, NMR spectracan be acquired in 3–4 minutes, and both GC and HPLCare usually limited to 3-minute experiments. Adequate super-vision, typically by student lab assistants, also keeps thingsmoving and helps teach students good technique. We alsouse advance scheduling to resolve conflicts between courses.A master schedule is prepared at the start of the semester. Insome cases different courses use the same instruments duringthe same lab period, in different assigned time blocks.

The second major issue regarding first-year usage ofinstrumentation is a pedagogical concern. First-year studentsneed to gain hands-on experience with chemicals, with reac-tions, and with laboratory techniques and manipulations.There is a certain gut-level understanding that comes fromdoing chemistry in a beaker, such as seeing PbI2 precipitatewhen Pb(NO3)2 and KI solutions are mixed. Does use of instru-ments preclude sufficient experience with “wet chemistry”?No! Even when extensive use is made of instruments, manyexperiments aren’t instrument based. Furthermore, good experi-ments involving instruments use them in context. Spectroscopy

follows synthesis, analysis follows sample preparation, just asin real-life chemical experimentation. In our experience, thehands-on chemical experience is just as strong in experimentsusing instruments as in other experiments. We aren’t advo-cating doing away with wet chemistry; we choose instead tointegrate it with the use of instrumental techniques.

Some would also argue thatinstruments are used as black boxesat the introductory level, and thatno chemical insight results. I guessa poorly designed and executed ex-periment might in fact end up thatway, (as would any poorly designedexperiment), but such flaws are notinherent in the use of instrumen-

tation. Good introductory material can provide informationon what instruments do in a way that reinforces core con-cepts of first-year chemistry (e.g., discuss polarity and solva-tion when using chromatographic instruments, atomic andmolecular structure when using spectroscopy).

We should not feel apologetic if first-year use of instru-mentation is somewhat simplified. We admit that our first-year students don’t get a full NMR introduction when weuse NMR in lab. In fact, we prefer to start with proton de-coupled 13C NMR because of its simplicity. But that sim-plicity does give a good introduction, leading to a multiyear,multilevel approach to instrumentation, encompassing thefull four-year curriculum. This approach is similar to the waywe structure our presentation of concepts over four years. Itis essential that the early stages of that multilevel approachmatch the students’ level of sophistication, providing inter-esting lab experiences without overwhelming their ability tocomprehend.

Modern chemistry uses instrumentation for good rea-sons. It is powerful and fast. Students need early exposure toinstruments for several reasons, including the motivating con-nection to real-life chemistry, the complementary nature ofthis type of laboratory experience, and the need to start learn-ing these powerful methodologies. The practical objectionsto such usage can all be handled if thoughtful attention ispaid to the details of experimental design and scheduling.Let’s allow our students the power and fun of using moderninstruments at all levels!

Literature Cited

1. Van Ryswyk, H. J. Chem. Educ. 1997, 74, 842–844.2. Heuer, E.; Koubek, E. J. Chem. Educ. 1997, 74, 313–315.3. Walters, C.; Keeney, A.; Wigal, C. T.; Johnston, C. R.; Cornelius,

R. D. J. Chem. Educ. 1997, 74, 99–102.4. Eichstadt, K. E. J. Chem. Educ. 1992, 69, 48–51.5. Jones, B. T. J. Chem. Educ. 1992, 69, A268–A269.

Jack K. Steehler teaches in the Department of Chemistry,Roanoke College, Salem, VA 24153-3794; phone: 540/375-2442; email: jsteehler@roanoke.edu.

We aren’t advocating doing away with

wet chemistry; we choose instead to

integrate it with the use of instrumental

techniques.