A How-To Guide on Using FTIR Spectroscopy Instruments

For those of us who enjoy chemistry and want to deepen our understanding, FTIR spectroscopy instruments are an invaluable tool that’s available to us at the click of a button. 

But figuring out how to use these powerful tools such as the Agilent FTIR spectroscopy instruments can be pretty confusing if you’re just starting. The following guide will help you understand how to get started using FTIR spectroscopy instruments in your research and lab work.

What is FTIR?

FTIR spectroscopies stands for Fourier transform infrared spectroscopy. Infrared is a form of electromagnetic radiation with longer wavelengths than visible light. It can be detected by certain materials to determine their molecular structure and chemical composition. 

IR can also tell us the spatial arrangements of bonds in molecules, the physical properties of surfaces, the shape or conformation of different species, and other information about atoms or molecules. The instrument used to record IR data is called an infrared spectrometer.

Who Can Use FTIR Spectroscopy?

The answer to this question is relatively straightforward. Anyone who has access to an FTIR spectrometer can use it as long as they have been trained in how to use the equipment. This includes university researchers, technical professionals, chemists and anyone with a vested interest in learning more about what these devices do. 

So essentially anyone with a connection to the web can find information about these powerful instruments which will help them make the most of what they have at their disposal. 

Indeed, the more people are aware of the capabilities and limitations of these tools, the better they will be able to adapt them accordingly so that they can extract all possible benefits from their interactions with this type of technology without risking wasting resources or generating inaccurate data results.


What are the benefits of using FTIR Spectroscopy?

FTIR spectroscopies are available from low-cost benchtop units to high-performance industrial instruments with single or multiple channels. These techniques cover a variety of applications, such as qualitative and quantitative analysis, quality assurance in the lab, production process control, industrial materials research, material development for optical coatings and inks and so on. 

FTIR spectroscopic data are used to understand molecular structure and bonding patterns. As such these measurements can provide unique insights into the chemistry that cannot be revealed by other physical measurements like IR or UV/VIS spectra.

Why use a spectrometer?

If you are looking to gain a basic understanding of how an IR spectrometer works and what information it can provide, this is the guide for you. If you have questions or need more in-depth discussions about spectral analysis, just let us know. 

An infrared (IR) spectrometer is an instrument that shines infrared light onto the surface of a sample. Different materials absorb different amounts of IR energy. The absorbance spectrum provides information about the surface material’s chemical composition and can be used to identify unknown substances through multivariate pattern recognition (MVP). 

In other words, IR spectra can provide detailed chemical information about organic or inorganic materials at a microscopic level of detail. Pretty cool!

What are the main types of IR analyzers?

Thermal IR analyzers are used to monitor temperatures and fuel levels, while Broadband IR analyzers provide a generalized overview of the composition of a material. Vibrational IR spectroscopies are used to study molecular vibrations; however, these techniques are often sensitive to environmental conditions. 

As such, some samples need to be cryogenically frozen to retain this vibrational information. Raman spectroscopy is most typically used for identifying the molecular bonds present in a given material (e.g., plastic vs. metal), but it can also be used for detecting elemental contaminants, explosives, or bacteria. A near-infrared region of the electromagnetic spectrum, which ranges from 700 nm – 1 μm (1 mm = 10 μm) is best suited for detecting chemical composition. 

Spectrophotometers measure the intensity of light at different wavelengths within the infrared portion of the electromagnetic spectrum. Most instruments measure four points: 2500 cm-1 (microwave region), 4000 cm-1, 600 cm-1, and 1800 cm-1 (near infrared). 

Infrared radiation is detected by an optical detector that generates an electrical signal proportional to light absorption as a function of wavelength. The results are displayed as a graph with peaks corresponding to certain frequencies.

So how do they work?

FTIR spectrometers are very intuitive and easy to use. When using a frequency-domain method for measuring the chemical makeup of materials, requires a sample, an infrared beam, and a detector with a grating monochromator. You can learn how to use these instruments with just a few quick steps.

First, you need to obtain your target material in either solid or liquid form. Next, set up the instrument by filling the sample cup and zeroing any frequencies that are not needed by adjusting the attenuation knob. Start collecting data by placing your target material within the focus of the infrared beam. 

The beam will scatter off the surface of the material and come into contact with the grating monochromator which splits this beam into its different wavelengths. The detector then collects all those wavelengths and converts them into a digital signal which is then translated onto a graph as spikes on one axis representing wavelength, height along another axis representing intensity. 

Main uses for IR spectrometers

IR spectrometers are used in many different ways and there are different types of spectrometers depending on the intended use. Generally, there are two main types of IR spectrometers: handheld and benchtop. 

Handheld IRs can be used by individuals to monitor a variety of situations in the field without having to leave the site, or they can be purchased for personal research or study. Benchtop IRs are typically used for scientific or industrial applications but some can also work at room temperature for educational demonstrations.


In conclusion, there are many important steps to take when using FTIR spectroscopy instruments. But these steps can be completed and the benefits derived through utilizing this technology. These benefits are product verification, quality assurance, better forecasting, material optimization and production line control. The implementation of such a system may be both expensive as well as complex but it is also very valuable to streamline business operations and provide a more cost-effective form of quality assurance testing that saves time and money.