Spectroscopy is the study of electromagnetic waves.
IR (infrared) spectroscopy is the study of infrared electromagnetic waves. The term spectroscopy refers to the analysis of the light wave dispersion phenomenon, which occurs when light passes through certain media such as prisms, glass and water. A light wave, when it passes through such a medium, splits into different, smaller electromagnetic waves which have distinct frequencies. IR spectroscopy only deals with those frequencies which fall under the domain of infrared, i.e. roughly between 300 MHz (megahertz) to 3 GHz (gigahertz).
Basics
IR spectroscopy primarily deals with the measurement of infrared energy, absorbed by molecules of different materials, in the form of waves. These molecules convert infrared waves into a form of usable energy, and utilize them for moving, stretching, and vibrating within the material structure. For this reason, measurement of the absorbed energy in molecules reveals important features of the material itself. These features include physical characteristics, molecular structure, purity level and other characteristics. The process of spectroscopy is performed by using an electronic device called IR spectrometer.
Process
To check different characteristics of a subject using general IR spectroscopy, IR light waves are first transmitted through it, usually with the help of an IR spectrometer. After that, an analysis of transmitted light waves is carried out by using different wave analysis techniques (such as Fourier transformation), which reveals the amount of energy absorbed by subject's molecules as frequencies. In this manner, only those particular IR frequencies are observed that get absorbed by the subject's molecules. Ultimately, these observations lead toward determining molecular structure, origin and several other characteristics of the subject.
Techniques
There are two most common techniques of performing IR spectroscopy i.e. classical and FTIR spectroscopy (Fourier transform IR spectroscopy). In the classical method, a single transmitting IR wave is split into two, with one passing through the subject and other passing through a reference material. These two waves are finally collected and analyzed for changes in frequency, power, wavelength and other things. In contrast, FTIR involves calculating the number of major frequency components present in the wave, coming from the sample, with the help of Fourier transform (a method to numerically check frequencies present in a wave form). When compared, FTIR is regarded much cheaper solution than classical technique of IR spectroscopy.
Applications
For many years, IR spectroscopy has been used by scientists and manufacturers to perform feature recognition processes of different elements and compounds. For this reason, it has some extensive applications in molecular, organic and non-organic chemistry. Specifically, it is used widely in the processes of compound identification and substance characteristics recognition. Moreover, IR spectroscopy also finds its huge application in the areas of forensic sciences, criminalistics, electronics (semiconductor evaluation) and pharmaceutics.
Limitations
There are many limitations and disadvantages of IR spectroscopy. The most acclaimed disadvantage lies in the hazardous nature of IR radiations, which can be very damaging for humans, animals and other living organisms. More specifically, IR frequencies are regarded as very high frequencies (as microwaves), which not only contribute to the destruction process of inorganic/organic environment, but also possess an ability to bring diseases (like permanent vision loss, skin diseases, etc.), especially for humans and animals.
Tags: electromagnetic waves, absorbed subject, absorbed subject molecules, characteristics subject, deals with, energy absorbed, Fourier transform
