Uses of IR Spectroscopy

Chemistry: Cambridge International A Level, topic 3.9.5

Practical Uses of Infrared Spectroscopy

IR spectroscopy, being able to identify the molecular composition of samples of matter, can be a powerful technique and has a diverse range of uses.

IR spectroscopy is used to measure the levels of dangerous pollutants (e.g. carbon monoxide and nitrogen monoxide).
These chemicals are damaging if inhaled so it is important to control their levels.
Miniature spectrometers can be set up on busy roads with a laser spanning the road.
The absorption data collected on the opposite side of the road can identify the pollutants present in the air at street level.
This setup is not restricted to roads and can be used in many different situations including measuring pollution levels across cities from the top of tall buildings.

Ethanol content in a sample of a person’s exhaled breath can indicate the alcohol content of the blood.
This can tell authorities whether someone should be allowed to drive.
A breathalyser is a portable device that uses IR spectroscopy to determine how much ethanol is present when somebody breathes into the machine.