Introduction
ATR has become the dominant method for collecting an FTIR spectrum of solid materials. It requires little or no sample preparation and is effective at both qualitative and quantitative measurements.
Compared to the older method of preparing a KBr pellet for transmission spectroscopy, important differences emerge. An ATR spectrum is not directly comparable to a transmission spectrum, although software algorithms are available in most commercial spectrometers capable of converting an ATR spectrum into a transmission-like spectrum should the analyst wish to compare them.
This note outlines the basics of the ATR method, providing the analyst with the information they require to gain the most out of the technique.