July 26, 2024
Journal Article

Optimal Spectral Resolution for Infrared Studies of Solids and Liquids

Abstract

Due to a legacy originating in the limited capability of early computers, the spectroscopic resolution used in Fourier transform infrared (FTIR) and other systems has largely been implemented using only powers of 2 for more than fifty years. In this study we investigate debunking the spectroscopic lore of e.g. using only 2, 4, 8 or 16 cm-1 resolution, and determine the optimal resolution in terms of both a) a desired signal-to-noise ratio and b) efficient use of acquisition time. The study is facilitated by the availability of newer solids and liquids reference spectral data recorded at 2.0 cm-1 resolution. The study is based on an examination in the 4000 – 400 cm-1 range of 61 liquids spectra and 70 solids spectra, with a total analysis of 4,237 spectral peaks, each of which was also examined for being singlet / multiplet in nature. Of the 1,765 liquid bands examined, only 27 had widths less than 5 cm-1. Of the 2,472 solid bands examined, only 39 peaks have widths

Published: July 26, 2024

Citation

Forland B.M., K.D. Hughey, M.J. Wilhelm, O.N. Williams, B.F. Cappello, C.L. Gaspar, and T.L. Myers, et al. 2024. Optimal Spectral Resolution for Infrared Studies of Solids and Liquids. Applied Spectroscopy 78, no. 5:486-503. PNNL-SA-189798. doi:10.1177/00037028241231601

Research topics