Determination of functional groups in coal by fourier transform interferometry

Critical evaluation of curve fitting in infrared spectrometry

Curve-fitting programs usually only yield accurate parameters for unresolved spectral bands when the separation of neighboring bands exceeds their average half-width. By reduction of the width of each spectral feature in a heavily overlapped band multiplet by Fourier self-deconvolution (FSD), the conditioning of curve-fitting algorithms is improved to the point that the area of each band in the multiplet can be estimated with much improved accuracy. The practical limitations of this approach are discussed in this paper. Most FSD programs are strictly applicable to Lorentzian bands; the effect of increasing the Gaussian fraction of isolated bands on the accuracy of band area estimation has also been investigated. Finally, the application of combined deconvolution and curve fitting to synthetic band multiplets in which the relative peak absorbances and bandwidths are varied is shown to yield accurate estimates of band areas until the band separation approaches the width of the instrument line-shape function, which is determined by the truncation, exponentiation, and apodization of the Fourier domain array.

Combined deconvolution and curve fitting for quantitative analysis of unresolved spectral bands

Measurement and use of absolute infrared absorption intensities of neat liquids

The determination of the optical constants of benzene and chloroform in the i.r. by thin film transmission

INTRODUCTION Before proceeding to our main topic, I want first to discuss the impact of the electronic computer on molecular spectroscopy. This is not intended to suggest that the use of a computer is an innovation in spectroscopic research. Many in this audience have employed electronic computers for several years to aid in the evaluation of molecular force fields, to calculate normal coordinates of the vibrations of polyatomic molecules, and to compute molecular energy levels by quantum mechanical methods. Until recently, however, the necessary computing facilities could be found only in a few specially equipped laboratories. In the two years that have passed since the Copenhagen Congress we have witnessed an explosive expansion in the availability of large electronic computers so that it is fast becoming the accepted practice to have extensive computation facilities as part of the standard services of the spectroscopy laboratory. Molecular spectroscopists use electronic computers in three distinct ways: (i) For data acquisition (ii) For data storage and retrieval (iii) For data analysis and interpretation arid it is convenient to consider these separately.

/pdf/the-measurement-of-infrared-spectra-with-digitally-recording-37b28jqkig.pdf

R. N. Jones

Papers

The measurement of infrared spectra with digitally recording spectrophotometers