High-Sensitivity Attenuated Total-Reflection Spectroscopy

Spectrophotometric analysis by attenuated total reflection was originally developed by Fahrenfort to utilize its low equivalent penetration of the light beam and, therefore, low sensitivity for the study of highly absorbent samples. Nearly simultaneously, Harrick proposed the method for the study of surfaces because of the low real penetration of the beam. Here sensitivity is at a premium, and in spite of the use of multiple-reflection techniques, it remained barely adequate for many cases. A considerable increase in the sensitivity of attenuated total-reflection spectroscopy (ATR) would not only resolve this problem but would make the technique useful in microanalysis because of the very low sample thickness required.