Spectroscopy basics

Applications of Infrared Spectroscopy

You'll find that almost every industry or institute in the world is using Infrared (IR) or Fourier-transform infrared spectroscopy (FT-IR) in their research, development, manufacturing, quality control, failure analysis, or forensics.

Why use FT-IR Spectroscopy?

FT-IR spectroscopy finds a home in laboratory setting across almost every scientific discipline: chemistry, life sciences, and of course physics. FT-IR is also used every day in pharmaceuticals, plastics, soil preservation, semiconductors, environmental studies, art, conservation, and so much more! The list could go on for miles. 

But why is that? Here are ten reasons why FT-IR finds widespread application in any setting

Easy to use
FT-IR spectroscopy is very easy to learn and can be performed by almost everybody.

Universally applicable
FT-IR spectroscopy can be used to analyze all materials: solids, liquids, or gases.

Cost effective
The acquisition cost is low compared to other lab equipment (e.g. GC, LC, XRD).

Reliable and reproducible
FT-IR instrumentation is internally calibrated for maximum reliability and productivity.

Time effective
Typical analysis time is about one minute including data evaluation and reporting.

Sustainable

FT-IR analysis is non-destructive, produces no waste, and uses no consumables.

Safe and non-toxic
FT-IR foregoes potentially toxic substances or harmful radiation.

Globally available
FT-IR instruments only require a lab-environment and electrical power.

Low space demand
The footprint of modern FT-IR instrumentation can be as small as a laptop.

Valuable for reverse engineering
FT-IR yields info about the chemical composition of any sample or product (including the competitor’s).

FT-IR is very efficient and saves time.

FT-IR does not need toxic chemicals.

FT-IR works with all sample types.

How can we use FT-IR spectroscopy? 

FT-IR at a basic level can be used for the identification or quantification of almost any substance. As chemical identification and quantification are critical tasks in most industrial and research settings, FT-IR spectroscopy has broad ranging applications. 

Chemical identification

Identification of unknown samples is one of the most typical applications of FT-IR spectroscopy - especially in damage analysis, competition analysis, and forensics. Based on comprehensive spectral reference libraries and modern search algorithms, unknown substances and even complex materials (mixtures) are identified without any prior knowledge.

Material verification

Materials and substances can be verified quickly and easily with FT-IR spectroscopy, making this technique an ideal choice for any quality control applications. FT-IR can be used to verify raw materials and incoming goods, as well as ensure the quality of the manufactured product. 

Quantification of components

FT-IR can also be used to quantify the constituents of multi-component samples with excellent precision all with a single measurement. This is done by calibrating the IR data using reference methods. 

Micro chemical analysis

When sample dimensions become too small for a macroscopic analysis, FT-IR spectroscopy can also be applied in microscopy. The instruments used are called FT-IR microscopes which are useful for failure analysis and quality control to investigate tiny contaminates.

Chemical imaging

IR microscopic imaging allows to generate high-resolution chemical maps of the object under investigation. This allows us to learn about the composition of inhomogeneous materials, to perform particle analysis (microplastics, technical cleanliness, pharmaceuticals), to detect defects in products, or to clarify the sequence of multilayer samples (coatings, paints, laminates, etc.). 

Laboratory use of FT-IR spectroscopy

As a chemical analysis technique, FT-IR spectroscopy has broad applications in many scientific disciplines.
As FT-IR is so quick and easy to use, it’s an excellent choice for many research topics. 

Chemistry

FT-IR can analyze almost any sample such as organic molecules, inorganic compounds and salts, and even larger structures like metal organic frameworks (MOFs).  This makes it an obvious technique for purity control and substance verification in a laboratory setting. It can be used at any stage of a reaction to examine the reactants, intermediates, or products.  

This technique is also an excellent choice for reaction control and monitoring since it requires no special solvents or sample preparation. During a reaction, an FT-IR spectrometer can create many spectra in a very short period of time, making it easy to examine the spectral changes of the reaction mixture as the reaction proceeds.  

FT-IR is also extremely useful in specific applications like battery research where it can be used to analyze all parts of a cell: the electrodes, electrolyte, catalysts, and membranes. It is also a valuable tool for examining catalysts in both an industrial and research setting as FT-IR can be used for both optimizing a catalyst and evaluating the load while the catalyst is in use. 

Life Science

A huge part of life science research is analyzing proteins. FT-IR can do this by probing the secondary structure of a protein, or the coiling and folding or the amino acid chain, though quantifying the amount of different structural features present such as α-helices and β sheets.

As the secondary structure informs the overall 3D shape of the protein, the overall structure of a protein can be understood with FT-IR. This makes FT-IR useful in many applications involving proteins such as detecting conformational changes or monitoring the stability of a protein in different conditions. This analysis can even be performed in water, making it an exceptionally straightforward technique for these applications.

This makes FT-IR useful for understanding various biological processes by monitoring the structure of proteins and enzymes over time. FT-IR can be used in natural products research to identify and characterize the compounds found in microorganisms, plants, fungi, and animals. It can also be used to understand biomaterials to optimize their properties for different applications. 

Physics

Physics research often involves monitoring extremely fast processes, which is possible with FT-IR using the step-scan technique. In this technique, the moveable mirror inside the FT-IR spectrometer moves step-by-step to sample data over time. This technique has excellent spectral and time resolution and useful for many applications including kinetics experiments, pump-probe experiments, studying electron transfer in biological compounds, or monitoring fast chemical processes. The step-scan technique can also be used to for time-resolved emission spectroscopy such as studying photoluminescence, fluorescence, or pulse laser emissions.  

The step-scan technique makes FT-IR a valuable tool in studying optoelectronics such as characterizing the emission spectrum Vertical-Cavity Surface-Emitting Lasers (VSECLs) to improve face recognition technology. FT-IR can also help characterize the optical and thermal properties of meta materials to be used in various technological applications.  

FT-IR is also a valuable tool in several research fields such as studying semiconductors as it can be used for clarifying the electronic structure and band gap. It can also a valuable tool in the development of semiconductors on the industrial level, since it be used for quantification, characterization, detecting impurities, and mapping silicon wafers. Superconductor research can also benefit from FT-IR spectroscopy for studying the charge and lattice dynamics.  

The applications discussed here only begin to scratch the surface on the many ways FT-IR can be applied. Due to the low cost, ease of use, and broad applicability FT-IR will continue to find new uses in research and in everyday life.

FT-IR spectroscopy is all around us.

FT-IR can be used in any industry for general applications like quality control, failure analysis, and competition analysis. Listing every specific application where FT-IR has found a use would make a list too long to document here, but let’s dive into some different areas where FT-IR is a critical technique.

Environmental analysis

FT-IR can analyze substances in practically any state: solid, liquid, or gas. This flexibility makes FT-IR an ideal tool for monitoring the quality of the water, air, or soil. FT-IR is also extremely valuable for determining the concentration of gases in the atmosphere, studying microplastic pollution, and monitoring biological processes occurring in nature.

Food science

As FT-IR can rapidly detect the components of mixtures, FT-IR is quite useful in the food and beverage industry. It is useful for analyzing the composition of food and drinks, detecting impurities or adulterants, and quality control of course.

But FT-IR can also be used in this industry for developing new manufactured foods. For example, FT-IR can analyze the proteins in the food to create products with a specific mouthfeel. 

Forensics

As FT-IR is a fast, nondestructive technique needing only small samples sizes, it serves an important role in analyzing most types of evidence that come into a forensics lab. It can be used to analyze fibers, residues, body fluids, and other substances found at a crime scene. Or it can be used to examine paint chips left behind in a hit and run accident to identify the offending vehicle. It can also be used to analyze and identify illegal drugs and substances. 

Pharmaceuticals

The pharmaceutical industry relies heavily on chemical analysis techniques for both research and industrial applications, and FT-IR has a role in almost every step of the process.During research, it can help characterize the materials to be used in drugs, even biological materials like proteins that are used for creating biopharmaceuticals.

It can also help us understand the stability of active ingredients when exposed to various conditions like heat and light. FT-IR can be used to study interactions between different ingredients, such as looking at protein interactions while developing a new vaccine. 

When the drug has been developed, FT-IR plays a crucial role in quality control as it can quantify the amount of each ingredient in a drug or check the drug for impurities. FT-IR microscopy can also analyze drug tablets to see if the active ingredient is properly distributed. 

Plastics and recycling
 

FT-IR can be used to analyze the composition of body fluids and tissue samples, making this a valuable technique in medicine. Using FT-IR to analyze blood is a great tool for health monitoring as everyone has a unique blood IR spectrum that changes in a way that reflects a person's health. FT-IR can also be used in early detection for diseases, and it can be used to significantly decrease the time it takes to test for disease.