The instruments that chemists use in their research have changed dramatically in the past decades. The explosion in new techniques and their instrumental counterparts has been made possible by two significant advances. The rapid propagation of computer chips and circuitry provides opportunities to collect more specialized and refined data than ever before. Computer-controlled instruments can detect events that a human researcher would never perceive and can record hundreds of data points in the time that a person could only observe one or two. Coupled with these advances in technology are advances in theory that allow more sophisticated interpretation of data.

A hundred years ago a sophisticated instrument was a balance that could weigh minute quantities. Today a sophisticated instrument is one that can identify the composition of that minute sample, determine its molecular weight, or reveal a great deal about its energy states and bonding. This bonanza of new instruments is wonderful for the research chemist but a curricular headache for the chemistry teacher. It takes more time to learn how to run an NMR than to use a balance, and more sophistication on the part of the student is needed to interpret the data. And yet many courses that only a generation ago sported an expensive analytical balance as its prize instrument now require students to understand and operate a whole panoply of complex tools. Teachers faced with accommodating these curricular changes will find several articles in this issue helpful--either providing information on new techniques or descriptions of how to incorporate them into the classroom.

Electrospray ionization mass spectrometry is one of the newest tools that has been added to the analytical arsenal. It is an extension of mass spectrometry that overcomes the old barrier that allowed only analysis of low molecular weight, volatile compounds. It is now possible to use MS for biomolecule and protein structure elucidation and it is becoming a routine biochemical tool. The explosive growth of this technique has stimulated the publishing of a three-part review in the Topics in Chemical Instrumentation feature. Part I, which covers instrumentation and spectral interpretation, is by Hofstadler, Bakhtiar, and Smith (page A82) and appears in this issue. They describe how the electrospray apparatus, which produces a fine aerosol of highly charged microdroplets, can be coupled with a mass spectrometer to analyze complex molecules. Next they show how the spectra achieved from this process can be interpreted using human hemoglobin as an example. This technique provides the ability to "weigh" large molecules in a manner unimaginable in the era of the two-pan balance and is thus a desirable addition to the curriculum.

The appearance of so many new technologies in the curriculum poses a problem for many teachers. They want to teach not only the manipulations required to run the instruments but also provide an understanding of the ideas behind them. Paniagua and Moyano (page 310) tackle the problem of how to introduce the principles of pulsed NMR and answer the basic questions in ways that undergraduates will understand. They discuss these in terms of the classical model, the naive quantum model, and the density operator approach.

Equally important to understanding the theory behind analytical instruments is understanding how they actually acquire and process data. Duffy and vanLoon (page 318) have designed an exercise to teach interfacing techniques in the instrumental analysis laboratory. Students use a relatively inexpensive interface unit and a PC to investigate the relationship among the signal generator, the detector, the signal modifier, and the output transducer in five real instrumental situations: temperature, light intensity, and potentiometric measurement; spectrophotometry; and redox titration.

The ubiquitous use of instruments and computer acquisition of data has made these techniques desirable even at the high school level. Students who are used to surfing the Internet on their home computer are ready to collect information via PC in their school labs as well. Bindel (page 356) takes advantage of the Personal Science Laboratory, an affordable package of probes and software for PC interfacing, to provide an experiment using the eye-catching lightstick as its object. Students use two methods to determine the activation energy of the reaction that produces the luminescence and explore concepts of kinetics as well as learn about computer-interfaced experimentation.

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