Fourier-Transform Infrared Spectroscopy
FT-IR operates by determining how a material interacts with infrared light. Certain infrared frequencies will cause the molecular bonds of a material to vibrate (resonate). Since different types of bonds vibrate at different frequencies, we can determine the identity of many materials by looking at the patterns of infrared absorbances (called a “spectrum”). This is particularly useful for organic components like plastics, paints, and drugs.
With the microscope attachment to our FT-IR, we can measure the infrared spectrum of even a single microscopic crystal of any material. Here is the spectrum of a single crystal of an unknown white powder submitted to us. (Fig. 1)
The spectrum was readily identified as methamphetamine. The process took less time than a commercial break from the TV show “CSI”. (Fig. 2)