RAMAN-SPECTROSCOPY FOR PROCESS QUALITY CONTROL/

Analytical instrumentation, especially Near Infrared (NIR), and Gas Ch romatography (GC) has been applied for a considerable number of years to the monitor and control of chemical manufacturing processes. By mea suring the chemical species at the time and place of manufacture it be comes possible to modify the quantities of feedstock and the physical conditions, either manually or automatically, in order to improve the efficiency of the process and/or the quality of the product. While the information content of Raman spectra was always attractive for this t ype of application, implementation of Raman instrumentation was imprac tical until the last several years. The evolution of Raman instrumenta tion in the last 5 years, as well as the implementation of the mathema tical data treatments that provide the needed quantitative information will be reviewed. Applications that are in the public domain will be described. This includes monitoring quality of hard carbon coatings on computer hard discs, chemical composition (mixtures, solvent separati ons, reactions such as polymerization, hydrogenation and curing etc.), gas composition, fermentation, polymorphy in pharmaceuticals, and pol ymer morphology. Rather than attempting to be exhaustive, the topics a nd literature covered will be selective - we will attempt to describe the state-of-the-art of a rapidly developing field, and give a sense o f its potential.