How an FTIR Works

The purpose of this chapter is to familiarize you with the inner workings of an FTIR and how to use this knowledge to optimize the qnality of the spectra you measure. The chapter concludes with a discussion of tests yon can rnn to insure your FTIR is working properly. 

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Designed for those new to FTIR, but with enough reference material to appeal to journeymen and expert spectroscopists alike, the book explains important FTIR topics in concise and comprehensible language. The book begins with the strengths and weaknesses of FTIR as a chemical analysis technique, describes how an FTIR works, and shows how to maximize spectral quality while minimizing analysis time. 

So far we have discussed how the parts of an FTIR work together to measure an interferogram and ultimately obtain a spectrum. It is now time to look at how each of these pieces works by themselves. 

MALDI to Elucidate Polymer Chemistry. Perhaps one of the most profitable future uses of MALDI will be for elucidation of polymer chemistry. Examining a reaction not yet complete or looking for polymer side products differing only by an end group will yield important reaction kinetics information. Unlike nmr, uv, or ftir, where one can perhaps find the presence of differing end groups or internal species for the overall MMD, MALDI can identify these species and how they can appear as a function of molecular mass. A caveat to all this work is the matrix attachment studies (21). Without carefiil studies of the linear and reflectron modes for each reaction examined and the effect of matrix and attached ion on the resultant spectra, one has to consider many of the conclusions from these studies tentative. 

Analysis of infrared spectra can teU you what molecules are present in a sample and at what concentrations this is why infrared spectroscopy is useful. There are several types of infrared spectrometers in the world, but the most widely used ones are FTlRs, which is the focus here. This book will teach you how FTlRs work, how to use them to obtain the best spectra, how to use FTIR software to assist in data analysis, how to properly prepare samples for FTIR analysis, how to quantify concentrations in samples using FTIR spectra, and infrared microscopy. In essence, we will be studying everything involved in obtaining a good infrared spectrum. For information on how to interpret an infrared spectrum to determine the structures of molecules present in a sample please consult my book on infrared spectral interpretation [1]. 

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