The modern practice of chemistry depends heavily upon instrumentation and the interpretation of the data it provides. At a time when chemical instrumentation is increasing in power, complexity, and cost, the instrumentation budgets of most institutions do not provide the resources necessary to take advantage of any new and improved capability. The result is that discussion of instrumentation not already on hand becomes more an exercise in the abstract and less a chance for students to get direct experience with the data these other methods and techniques provide. Confining lectures, dry-labs, and homework assignments to spectra or chromatograms photocopied from textbooks and journal articles will go only so far when trying to convey a sense of what can be gained from other instrumental methods and what it is to have access to "real" data. Even when instrumentation is available, time constraints may prevent access or utilization for educationally meaningful applications, leaving students in a position to simply accept generalizations as true. A freeware product from Galactic Industries Corp. (Salem, NH), however, provides a means to share actual data from a wide variety of instruments among interested parties, increase student involvement with data, and help overcome the limitations mentioned earlier.

The Galactic DataViewer software (1) is a freeware product designed to allow those who are not users of Galactic's GRAMS/386 or GRAMS/32 (2) commercial software packages the capability to open spectral and chromatographic files stored in Galactic's SPC format. Available only for the Windows 95 and NT platforms, the DataViewer software requires 350 kB of disk space when fully installed and may be run as a stand-alone application for files on local or network disk drives or as a helper application for Netscape, Internet Explorer, and other Web browsers once they have been suitably configured. The spectra presented here (Figs. 1-3) are intended to briefly demonstrate the variety of instrumental methods and manufacturer file formats supported by the GRAMS commercial software, which could then be made available for viewing using the DataViewer freeware. Though not shown here, chromatograms and mass and NMR spectra can also be converted to the SPC format and viewed in DataViewer. For vendors not directly supported, import filters for ASCII XY data files and the J-CAMP format exist. Information available from the Galactic Industries Inc. home page (1) will allow those who do not own a commercial Galactic product to write simple programs to convert their data files.

Figure 1. DataViewer display of poly(styrene) FTIR spectrum acquired on a Mattson Polaris FTIR. Resolution is 2 cm^-1, 16 scans added. Data were converted from the Mattson FIRST format using GRAMS/386. Transmission for a particular wavenumber can be determined by the boxes on each axis, which indicate cursor position.

Figure 2. DataViewer display of NiEDTA²⁺ UV-vis spectrum acquired on a Perkin-Elmer Lambda 6 spectrophotometer. See ref 3 for experiment details. The original data were exported as a J-CAMP file instead of the Perkin-Elmer DX format. Both formats can be converted using GRAMS/386.

Figure 3. DataViewer display of chloroform Raman spectrum acquired on a Jobin-Yvon U1000 with 514.5 nm excitation (Ar⁺ laser). Spectral resolution is 3 cm^-1, with 0.5 s integration per point. Data were converted from the ISA S00 format using GRAMS/386. As in Fig. 1, the cursor has been placed near the top of one peak to demonstrate how signal intensities and positions can be obtained.

Once a file has been opened by DataViewer, the scale of the spectrum (mass, NMR, or spectroscopic) or chromatogram (all referred to hereafter in GRAMS terminology as a "trace") may be expanded or compressed as needed to explore features (the original view may be restored at any time via the toolbar or menu command). Peak heights, intensities at full width half maximum, and approximate baseline levels may be determined by moving the cursor to the desired point and then clicking once with the left mouse button (Figs. 1 and 3). Galactic has not, however, included any smoothing, deconvolution, background subtraction, file import/export, or peak integration functionality in the DataViewer software. Any processing of this type must be performed using the commercial GRAMS software and saved to a file before viewing with DataViewer. Text labels and special color formatting added in the commercial GRAMS products are not visible using DataViewer, but are still present in the file and not affected by viewing in DataViewer. If hard copies of the entire trace or any expanded region thereof are desired, DataViewer supports any printer or plotter installed under Windows 95/NT (including networked printers). If users wish to include all or part of the trace in another document (e.g., a lab report), DataViewer will copy whatever is currently displayed (complete trace or expanded region) to the Windows clipboard for pasting into another application.

GRAMS DataViewer software has potential applications in both the laboratory and the lecture settings for any course that includes instrumental data. In both instances, there are three methods for utilizing the software: floppy disk, local computer, or Web based. The small size of the DataViewer program and associated DLL files (350 kB total) allows the software to be run off a floppy disk for any Windows 95/NT-based system, and the small size of most SPC files (less than 20 kB is typical) means they can be stored on the same floppy. Disks can be prepared for a single assignment or course, made available for student checkout, and used on any Windows 95/NT computer at school or at home. Although running off the floppy drive does slow down performance, especially on older 486 machines, the delays are not prohibitive. More challenging, perhaps, is the task of having enough of the "correct" floppies on hand for student use, or providing some means by which students can download the program and data files onto their personal disks.

For local computer access, all SPC files for a single class could be stored in a dedicated directory or further subdivided into subdirectories devoted to a single unit of the course. Students would then look in the appropriate location for the necessary files. By using DataViewer on individual computers, the storage space available is much greater than for a floppy disk, with an added benefit of faster file access. With DataViewer installed on several systems, it is possible for students to simultaneously work with the same or different traces, the only limitation being the number of available machines. These advantages are tempered by two concerns: system uniformity and system security. If DataViewer is to be used on multiple systems, time must be expended to insure the directory structure on all systems is identical and any changes must be made manually to all. For Windows 95-based systems where there is no security built into the operating system, deletions or unauthorized movement of files (intentional or accidental) cannot be prevented. Neither of these is possible from within DataViewer, but both can be easily accomplished by students of all abilities using the Windows File Manager or Explorer.

Web-based access requires a onetime configuration of the Web browser (Microsoft's Internet Explorer excepted because of how it is able to access Registry information) and Web server software. Up-to-date instructions for configuring Netscape, available online (1), detail how to establish DataViewer as a "helper application." The Web server software must be modified to properly transmit the MIME type of the SPC files (4) so that the browser knows which application to launch for the file being transmitted. After proper configuration, simply clicking on a link in a Web page (<a href="xxx.spc"> format) will automatically launch the DataViewer to display the trace. Once displayed, the "Save As" function may be used to save a copy of the trace to a local disk drive for future use (using a file name given by the user). The three advantages to Web delivery are central file administration, file security, and simultaneous access for any number of systems. Central file administration and security are provided by the Web server hardware and software. With a limited number of authorized users, files may be added, deleted, or moved as needed, but only by authorized users. Once a change is made to the contents of the Web server, the change takes immediate effect for anyone accessing the files. Simultaneous access is a misnomer, since the Web server must process each request sequentially over as few as one network connection, but the speed of most servers is usually sufficient that on a campus LAN the net effect is simultaneous access. For situations where the ratio of students to computers is high and there is a need to access DataViewer files, a Web-based approach provides tremendous flexibility, since the only requirement for access is a network connection, a Web browser, and DataViewer installed on the hard disk. Two minor advantages to Web delivery are that students simply go to the appropriate Web page and click, avoiding the need to master a series of subdirectories in order to find files, and that students can access files from home via an Internet service provider (ISP) connection. Without Web delivery, students unfamiliar with a disk's directory structure may have difficulty finding files and students wishing to work from home need to borrow disks containing the necessary files. (Web delivery is especially attractive for larger classes where the number of disks and tracking their whereabouts could quickly become prohibitive).

Regardless of the delivery method chosen, DataViewer can serve a variety of uses in both the laboratory and lecture setting (see list below). The common laboratory theme is providing students with experiences that would not otherwise be possible because of equipment or time constraints. Lecture uses center around making data more real and thus, it is hoped, expanding learning beyond the textbook and lecture.

Summary of DataViewer Uses and Advantages

In the Laboratory

If no instrument available

If no access to instrumentation on hand

If no access to down instrument

Long acquisition times with instrument

Repetitive acquisitions required

For correlative/complementary techniques

For reference spectra

In the Lecture

Lecture support

Homework assignments

In instances where an instrument is not available (not present, no access, or out of service), the DataViewer allows an electronic dry lab to proceed so long as the data manipulation functions mentioned above are not required. With this idea in mind, a Raman lab has been developed around the DataViewer software (5). Smoothing, correction, and other manipulations may be demonstrated through a series of files so that the process used is understood. For institutions of all sizes and financial means, DataViewer provides a way to expose students to concepts and methods they would otherwise have to forgo. For some experiments, equipment access is not an issue but data acquisition time isfor example, when extremely long analysis times or repetitive acquisitions on one or more samples are required. In these cases, student fatigue may prevent maximization of concept retention and instead minimize interest. With a set of previously acquired spectra or chromatograms, students could quickly move from the instrument (after a reasonable number of acquisitions) to DataViewer to complete the lab assignment and thereby focus on the main idea of the lab and not simply repeat acquisition after acquisition.

While practicing chemists recognize the value of correlative techniques, time constraints in most labs make their use difficult. With DataViewer, however, correlative data are available off-line and can be added to an experiment without requiring a significant amount of lab time. One suggested starting point for this arrangement would be the commonly used analysis of analgesics by either HPLC (6, 7) or UV-vis (8, 9). Assuming that students are already familiar with UV-vis spectroscopy, the experimental section could focus on HPLC analysis, using the DataViewer to access the UV-vis results for comparison of quantitative results or peak identification. Taking this idea one step further, DataViewer could be used to emphasize the complementary nature of certain techniques, such as IR and Raman spectroscopies. The effects of key instrumental parameters could also be quickly demonstrated without requiring cumbersome lab procedures involving the instruments themselves, and incorporated into prelab assignments to help students recognize the underlying cause(s) of data that are not as expected.

Determining what the expected data look like is another possible use of DataViewer. By assembling reference spectra and chromatograms, students could confirm that they are on the right track or, with files demonstrating the effects of common mistakes in setting instrument parameters, troubleshoot their work. Inserting a paper copy of the expected data into a lab procedure is easy enough, but including examples of "bad" data may become unreasonable. Using the DataViewer, however, requires only that a statement referencing the online data be inserted in the procedure. Updates and inclusions of DataViewer files can made at any time, keeping this type of help as current as possible.

In the lecture setting, the DataViewer becomes either a means for providing data in class (via a suitable projection system) or a tool for out-of-class assignments. In both cases DataViewer is used to make the data more alive for students and draw them into it, as opposed to their simply looking at one more paper spectrum or chromatogram. A common concern with textbooks is what has been left out in order to keep the text at a reasonable size. Series of spectra or chromatograms that might convincingly demonstrate a point or answer a "what if" question may be missing, but could be supplied by the instructor using the DataViewer in lecture. Such spectra could be made available outside of class as well. Examples of this would be to demonstrate the effect of ligand or solvent strength on UV-vis spectra, use IR or NMR files to determine the product of a synthesis reaction, or demonstrate the use of molecular symmetry and selection rules in conjunction with IR or Raman spectra. Outside of class, DataViewer provides an opportunity for more interactive homework problems. This idea has already taken form in the Spectroscopy Spectral Challenge, where spectra from complementary techniques are available via the WWW in the SPC format and readers are asked to determine the identity of the unknown (1).

The GRAMS DataViewer software can be used in a way that matches the needs of each institution and at the same time provides students with increased opportunities to become involved with the data available from chemical instrumentation. It is easy to install as a stand-alone application or as a helper application for Web browsers, maximizing the flexibility instructors have in how it will be used in their classes. Once the software is configured, the instructor need only inform the students of the Web location of the data. Web locations may include sites from all around the world or the Web page dedicated to the particular class. I have already used DataViewer to make up for an instrument temporarily out of service, provide reference spectra in an instrumental analysis lab, and provide students with copies of a limited number of spectra in class. It has been easy to integrate and is becoming more useful now that others have begun to post data on the Web (10).

Notes and References

1. http://www.galactic.com/.

2. GRAMS/386 and GRAMS/32 are registered trademarks of Galactic Industries Corp.

3. Dado, G; Rosenthal, J. J. Chem. Educ. 1990, 67, 797-800.

4. In keeping with the MIME-type assigned or suggested by Galactic Inc. in the Netscape configuration instructions, the Web server software should have the following line added to the MIME configuration file/section:

type=chemical/x-spectra exts=spc,SPC

5. Fetterolf, M. L.; Goldsmith, J. G. J. Chem. Educ., submitted for publication.

6. Kagel, R. A.; Farwell, S. O. J. Chem. Educ. 1983, 60, 163-166.

7. Haddard, P.; Hutchins, S.; Tuffy, M. J. Chem. Educ. 1983, 60, 166-168.

8. Kealey, D. Experiments in Modern Analytical Chemistry; Chapman & Hall: New York, 1986; pp 56-57.

9. Sawyer, D. T.; Heineman, W. R.; Beebe, J. M. Chemistry Experiments for Instrumental Methods; Wiley: New York, 1984; pp 211-212.

10. Galactic Industries Inc. is trying to keep an updated list of different sites and the types of data each specializes in. Visit their home page for the most current listing.