Infrared (IR) spectroscopy

Infrared (IR) spectroscopy is a technique used to study the vibrational modes of molecules by measuring the absorption or transmission of infrared radiation. In IR spectroscopy, a beam of IR light is passed through a sample and the amount of light absorbed by the sample is measured as a function of the frequency or wavelength of the light. This produces an IR spectrum, which can be used to identify the functional groups and chemical composition of a sample.

 

IR spectroscopy is commonly used in analytical chemistry, biochemistry, and materials science for a variety of applications, such as:

Identification of unknown compounds:

 IR spectra are often used to identify the functional groups and chemical composition of an unknown compound.

Quality control of drugs and pharmaceuticals:

 IR spectroscopy can be used to monitor the purity and quality of drugs and pharmaceuticals.

Characterization of polymers:

 IR spectroscopy is used to study the chemical composition and structure of polymers.

Analysis of food and beverages:

 IR spectroscopy is used to analyze the chemical composition of food and beverages, including the identification of additives and contaminants.

Overall, IR spectroscopy is a valuable tool for the identification and characterization of a wide range of materials and compounds in various fields of science and industry.

 Several types of IR spectroscopy are commonly used in analytical chemistry and materials science. Some of the main types of IR spectroscopy include:

Fourier Transform Infrared (FTIR) Spectroscopy:

 This is the most commonly used type of IR spectroscopy, which uses a Fourier transform technique to convert the measured signal into a spectrum. FTIR is highly sensitive and can be used for qualitative and quantitative analysis of various samples.

Attenuated Total Reflection (ATR) Spectroscopy:

 In this technique, the IR beam is passed through a crystal surface, and the sample is placed in contact with the crystal. ATR spectroscopy is used for  analysis of solids, liquids, and gases and is useful for the surface analysis of thin films.

Gas-phase IR Spectroscopy:

 In this technique, the sample is in the gas phase, and the IR beam is passed through the gas. This technique is useful for the analysis of gas-phase molecules and can provide information on the molecular structure and conformation.

 

Reflection Absorption IR Spectroscopy:

 This technique is similar to ATR spectroscopy but is used for the analysis of thin films and surfaces. In reflection absorption IR spectroscopy, the IR beam is reflected off the surface, and the absorption spectrum is measured.

Near-Infrared (NIR) Spectroscopy:

 This is a type of IR spectroscopy that uses the near-infrared region of the electromagnetic spectrum. NIR spectroscopy is used for the analysis of organic and inorganic compounds and can provide information on the molecular structure and functional groups.

Overall, the choice of IR spectroscopy technique depends on the sample type, sample size, and the information required.