Spectroscopy
Infrared spectroscopy (IR spectroscopy) or vibrational spectroscopy measures the interaction of infrared radiation with matter using three main measurement techniques: transmission, attenuated total reflection (ATR), and reflection. It is used to study and identify chemical substances or functional groups in solid, liquid, or gaseous forms and can be used to characterize new materials or identify and verify known and unknown samples.
As each chemical species will have vibrations at different frequencies, the resulting spectrum of each compound will be unique. This means IR spectroscopy creates a “chemical fingerprint” that can be used to identify and quantify almost any chemical species.