What is the difference between IR and FTIR?

IR refers to the analysis technique of infrared spectroscopy, which was pioneered in the early 1900s. These days, Fourier transform infrared spectroscopy (FTIR) is more commonly used as it makes the analysis much easier to perform. FTIR also delivers much faster analysis, increasing its popularity in cutting-edge applications.

How does Fourier transform infrared spectroscopy work?

FTIR works by measuring the light absorbed or reflected when infrared light is passed over a sample. The Fourier transform results in spectra that can be used to quantify the molecular structure of the sample.

What is the main principle of FTIR?

FTIR works on the principle of absorption, whereby a sample is exposed to infrared light, and the absorption or reflection of the light is measured.

FTIR Spectroscopy

Q: How is the Fourier transform used in spectroscopy?

When Fourier transform is discussed within the context of spectroscopy, it refers to the mathematical process used to convert the interferogram or raw signal into an analysis of a sample. Its data is showcased as an infrared spectrum that identifies its molecular structure.

Q: What is the Fourier transform infrared spectroscopy protocol?

FTIR protocol involves passing infrared light over a sample to measure the light absorbed or reflected. This data is then captured in a spectrum that showcases the sample’s molecular structure and composition.

Fourier transform infrared spectroscopy (FTIR) is an analysis technique used mainly for structural estimation (qualification) of organic compounds of solid, gas and liquid samples. When molecules are irradiated with infrared rays, they absorb infrared rays equivalent to the vibrational energy between the atoms that make up the molecules. A Fourier Transform Infrared (FTIR) Spectrophotometer is used to estimate and quantify the structure of compounds by examining the degree of absorption. FTIR is frequently used in a wide range of structural analysis and non-destructive measurement applications.

Due to the simplicity and versatility of the measurement, FTIR is used for structural identification in many industries and applications. FTIR is incredibly useful for the pharmaceutical industry for both research and quality control of existing products.

Shimadzu offers a complete FTIR product lineup, from the compact FTIR, IRSpirit-X, which provides reliable, versatile and high-performance, and IRXross which provides stable FTIR analysis, to the high-end IRTracer-100 for sophisticated research. Shimadzu FTIR systems, offering high resolution, high sensitivity and simplicity, offer a wide range of solutions.

Features of Shimadzu’s FTIR

Shimadzu's FTIR systems combine high performance with operational ease to meet the demanding needs of the pharmaceutical, chemical industries and more. These best-in-class instruments incorporate the following features:

High resolution

Shimadzu’s FTIR systems are in high demand for achieving new levels of performance and quality through exceptional speed, resolution and sensitivity. The IRTracer-100, for example, features the highest signal-to-noise (S/N) ratio in its class (60,000 : 1), along with 0.25 cm⁻¹ resolution, and high-speed scanning at 20 spectra/second.

Superior sensitivity

The performance of mid- and high-end FTIR models, including the IRTracer-100 and IRXross, is supported by features such as advanced dynamic alignment and an interferometer equipped with a dehumidifier. These enable highly sensitive and reliable analysis.

Software integration

LabSolutions IR software is optimized for network applications. It includes an extensive library of spectra, and features a high-performance search function. In addition, Macro functions enable automation and labor savings. LabSolutions IR simplifies FTIR operations such as scanning, data manipulation, quantitation, reporting, saving, user administration, and more. Advanced administrative functions and a variety of data manipulation functions create an easier and user-friendly analysis environment. Additionally, a wide range of optional programs are available to meet the diverse needs of modern laboratories.

Stability

By combining Shimadzu's own algorithms (patent pending) with a comprehensive library of spectra for common contaminants, LabSolutions IR identifies contaminants with a high degree of accuracy. This easy-to-use program supports operators of all experience levels by automatically generating reports after analysis, making it easy for the operators with limited knowledge of infrared analysis to use the suite of FTIR.

FTIR Measurement Method

FTIR encompasses four main measurement method, which are as follows:

Transmission Spectroscopy

This technique is considered the traditional method of FTIR and is ideal for analyzing thin films, liquids, and gases. Transmission FTIR involves infrared light passing through the sample to analyze and share its molecular data via a spectrum. Shimadzu’s IRSpirit-X, IRTracer-100 and IRXross are highly reliable spectrometers capable of performing transmission FTIR measurements.

Attenuated Total Reflectance (ATR) Spectroscopy

The ATR (attenuated total reflection and internal reflection) technique is attractive for a wide range of application (e.g., films, rubber, polymers and liquid samples) because sample pretreatment is unnecessary to obtain information from the surface of the sample. The effects of the ATR technique on a sample spectrum are well characterized. For example, the depth of penetration is inversely proportional to increase wavelength. Therefore, the peak intensity generally decreases as one proceeds from the low wavelength to the high wavelength side of a spectrum. In samples that possess a high refractive index, one may observe peak distortion, skewed baselines, and shifts in both the peak positions and the peak intensity in the spectrum.

Diffuse Reflectance Spectroscopy

This technique of FTIR is frequently used for powdered samples, as it relies on the collection of scattered infrared energy rather than forming an analysis based on infrared light passing through the sample. As the growing popularity of FTIR, this approach has become more common. Since the diffuse reflection method offers more information about substances adhering to the sample surface than transmission methods, and it also allows vacuum heating measurements. For these reasons, it is widely used in the field of catalysts. Note that Diffuse Reflectance requires the use of an additional accessory.

Specular Reflection Spectroscopy

Light that reflects back at the same angle as the angle of incidence is known as "specular reflection light." The FTIR method that exploits specular reflection light is called the "specular reflection method." When using the specular reflection method, the sample can be irradiated with infrared light at either a nearly vertical or nearly horizontal angle of incidence. A specular reflection accessory that irradiates the sample with infrared light from an almost vertical angle is used to measure the infrared spectra of relatively thick, µm-order, metal coatings, or to measure the film thickness on epitaxial wafers using interference fringes.

FAQ

How is the Fourier transform used in spectroscopy?

When Fourier transform is discussed in the context of spectroscopy, it refers to the mathematical process used to convert the interferogram into the wave intensity at each period. Its data is displayed as an infrared spectrum that identifies its molecular structure.

What is the Fourier transform infrared spectroscopy protocol?

FTIR protocol involves passing infrared light through a sample to measure the light absorbed or reflected. This data is captured as a spectrum that reveals the sample’s molecular structure and composition.

What does the FTIR tell us about?

FTIR offers high-resolution, highly sensitive data pertaining to the chemical composition, structure, properties and concentration of solid, gaseous and liquid samples.

Show Less