An Ultimate Guide to FTIR Spectroscopy

FTIR spectrometers find widespread use in organic synthesis, polymer research, petrochemical engineering, the pharmaceutical sector, and food analysis. In addition, FTIR spectrometers may be used with chromatography, allowing for the study of chemical reaction mechanisms and the identification of volatile compounds.

An Ultimate Guide to FTIR Spectroscopy

Discover more about  FTIR spectroscopy with the help of this thorough reference below.

About FTIR

FTIR spectroscopy, often known as Fourier transform infrared spectroscopy, is a category of IR spectroscopy. The most common kind of infrared spectroscopy is called Fourier transform infrared (FTIR). 

When infrared radiation allows it to pass through a sample, it absorbs some of the radiation while another energy flows through. The signal received by the detector represents the sample's molecular "fingerprint" as a spectrum. 

Infrared spectroscopy serves a use because various molecular configurations generate distinct spectral signatures. The Fourier Transform transforms the detector output into a readable spectrum. Additionally, FTIR can develop ranges that include patterns that provide insights into the structure of a substance.

How Does FTIR Work?

Since different molecules absorb infrared light at different frequencies, it is possible to utilize the spectra to distinguish between them. Due to the unique mix of atoms, each molecule structure generates its distinctive range when subjected to infrared light. 

A molecule's identity may be determined even if it has the same amount of atoms, but they are all in a different arrangement. Only diatomic atoms like oxygen and noble gases do not absorb in the infrared. Each molecule has a distinct IR absorption spectrum, which may be a fingerprint.

A plot of infrared radiation-related parameters against wavelength or wavenumber yields the infrared spectrum. It may use the IR spectrum to calculate gas concentrations in the sample using Beer's law, which states that absorption intensity (peak height) is proportional to concentration.

About Transmission FTIR Spectroscopy

The transmission mode is a standard Fourier transform infrared (FTIR) spectroscopy process. Whether it's a liquid, gas, powder, or film, transmission FTIR spectroscopy can analyze anything. Transmission spectroscopy uses an FTIR detector on the other side of the sample to pick up infrared radiation.

Using demountable or flow cells for FTIR analysis of liquid samples is complicated. The following factors contribute to making the usage of these cells difficult, error-prone, and time-consuming:

  • Cells are delicate and complex to put together.
  • The layout makes it difficult to get consistent path length measurements.
  • There is a tendency for leakage in cells.
  • Air bubbles may hamper analysis.
  • The time required for cell cleaning and assembly is substantial.
  • It's challenging to introduce samples that are sticky or viscous.
  • It takes a lot of sample volume and solvent for washing.

However, it may avoid these difficulties by using Agilent FTIR spectroscopy instruments and sample methodologies. It will make FTIR spectroscopy of liquids simple, straightforward, and productive.

FTIR Spectrometers Components

An FTIR spectrometer comprises a few different components, all working together.​ It contains a computer, amplifier, A/D converter, source, detector, sample compartment, and an interferometer. 

Each sample gets exposed to radiation from the source, which travels through the interferometer and is then detected. The signal is then boosted by the amplifier and transformed to digital form by the analog-to-digital converter. Within a specific time of the procedure, the signal goes to a computer, which then utilizes it to carry out the Fourier transform.

What is the Function of an FTIR Spectrometer?

There are three fundamental parts to every FTIR spectrometer. First, infrared light comes from a source specifically designed to produce it. 

It's an interferometer, too, with the added capability of altering the infrared light's spectrum in real-time. Last but not least, it is a detector that determines the amount of light present.

The infrared light is divided in two as it enters the interferometer through a beam splitter. A fixed mirror reflects the first beam, while a movable mirror does the same for the second. 

The second beam's path length varies continuously due to the mirror's back-and-forth motion. At the beamsplitter, the two beams cross paths once again and cause interference with one another. 

This signal strength vs. time function (= mirror position) is recorded by the detector and named "interferogram." The computer then converts it into a frequency spectrum, or a plot of signal strength against frequency/wavenumber, through the Fourier transform.

Find Out More Information About FTIR Spectroscopy

Infrared spectroscopy utilizing the Fourier transform is a method that IT may use to produce an infrared spectrum depending on the amount of IR absorption or transmission in a material. Fourier transform infrared spectroscopy (FTIR) is widespread in diverse nondestructive measurement and structural analysis applications.​

Infrared spectrometers of the FTIR type are considered the third generation of this instrument. FTIR spectrometers provide you, as their user, with several significant benefits and are reliable instruments.