Document Type


Publication Date


Subject: LCSH

Barium Fluoride, Infrared microscope


Forensic Science and Technology


The infrared (IR) microspectroscopical analysis of samples within a sealed-cell containing barium fluoride is a critical need when identifying toxic agents or suspicious powders of unidentified composition. The dispersive nature of barium fluoride is well understood and experimental conditions can be easily adjusted during reflection–absorption measurements to account for differences in focus between the visible and IR regions of the spectrum. In most instances, the ability to collect a viable spectrum is possible when using the sealed cell regardless of whether visible or IR focus is optimized. However, when IR focus is optimized, it is possible to collect useful data from even smaller samples. This is important when a minimal sample is available for analysis or the desire to minimize risk of sample exposure is important. While the use of barium fluoride introduces dispersion effects that are unavoidable, it is possible to adjust instrument settings when collecting IR spectra in the reflection–absorption mode to compensate for dispersion and minimize impact on the quality of the sample spectrum.


This is the authors' accepted manuscript of the article published in Applied Spectroscopy. The version of record can be found at



Publisher Citation

Kammrath, B. W., Leary, P.E., & Reffner, J.A. (2016). Collecting Quality Infrared Spectra from Microscopic Samples of Suspicious Powders in a Sealed Cell. Applied Spectroscopy. doi: 10.1177/00037028166662860. epub ahead of print Sept 19, 2016.