Author
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Barton Ii, Franklin |
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Submitted to: NIR news (Near Infrared Reflectance News)
Publication Type: Trade Journal Publication Acceptance Date: 5/1/2003 Publication Date: 5/31/2003 Citation: BARTON II, F.E. PROGRESS IN NEAR INFRARED SPECTROSCOPY: THE PEOPLE, THE INSTRUMENTATION, THE APPLICATIONS. NIRNEWS (NEAR INFRARED REFLECTANCE NEWS). 2003. V. 12(2). P. 10-12. Interpretive Summary: This article is a transcript of an award presentation. It describes progress in the field of Near Infrared spectroscopy for the past 40 years. Technical Abstract: The history of Near Infrared begins in 1800 with Herschel. His experiments to find a way to filter heat from a telescope demonstrated that there was light radiation beyond what we know as the visible spectrum. This discovery was largely ignored for the better part of a century and even longer before modern instruments were used to acquire spectra. In the mid-1950's Wilbur Kaye with Beckman Instruments published two studies which put NIR spectroscopy on a firm footing. These studies described the instrument and the theoretical basis for the spectra in di- and tri-atomic molecules from group theory and selection rules5. The emergence of NIR into the analytical world as an accepted technique began with the work of Karl Norris of the U.S. Department of Agriculture, Agricultural Research Service in the early 1960's. This was followed by the USDA/ARS National NIR Research Project which developed into a worldwide network of collaborating laboratories. This research project's efforts culminated in the publication of handbook #643 and two AOAC International Official Methods. From this point NIR Spectroscopy flourished and expanded well beyond the agricultural realm into pharmaceuticals, industrial, process control, food processing, remote imaging spectroscopy and other diverse applications. In the early days of NIR spectroscopy instruments were not computer controlled and in some ways simpler but harder to use than the modern spectrometers we use today. The first NIR instrument I used was a Beckman DU which did not even have a recorder to plot the spectrum. The Cary 14 was the first recording NIR I used. This instrument was the one Karl Norris used in his research combined with a Hewlett-Packard calculator to do the statistics, later replaced by a mini-computer. Like all industries, the instrumentation industry for NIRS underwent growth, acquisitions and mergers. As the 90's came to an end the NIR community was still heavily into dispersive instruments and the mid infrared was totally into FT instruments. For many years the agricultural community used NIR to measure compositional analysis of agricultural commodities and were concerned with taking the spectrum of a series of samples to the same exacting specifications. Those in the MIR community were interested in the taking the best spectrum of the analyte. These two positions were somewhat mutually exclusive and remain so today. The NIR user is still "model" and "statistically" oriented and the infrared user is still concerned with functional groups, resolution and spectral interpretation. However, as with sampling devices the applications are forcing changes in the instrumentation. Applications for online analysis in mixed matrices can require both high resolution and high signal-to-noise (S/N). Two dimensional spectroscopy has open avenues of interpretation previously unavailable in NIR spectroscopy. The use of NIRS to determine rheological properties for end-use determination of grains has been accomplished recently. There are many new applications and tools to help make NIRS a tool of choice for analytical solutions. |
