ReactIR In-Situ Reaction Analysis
Understand Reaction Kinetics, Mechanisms, and Pathway to Optimize Reaction Variables
ReactIR™ FTIR spectrometers enable scientists to measure reaction trends and profiles in situ and in real-time, providing highly specific information about kinetics, mechanism, pathways, and the influence of reaction variables on performance.
Using ReactIR, directly track reactants, reagents, intermediates, products, and by-products as they change during the course of the reaction. ReactIR provides critical information to scientists as they research, develop and optimize chemical compounds, synthetic routes, and chemical processes.
In-Situ FTIR Spectroscopy Equipment for Stable, Scalable, Consistent Process Development
ReactIR 701L
Liquid Nitrogen MCT
High-sensitivity detector with >24 hour hold time for demanding applications. Läs mer
ReactIR 702L
TE-Cooled MCT
Solid-state detector cooling delivers high performance without the need for liquid nitrogen. Läs mer
ReactIR 45P
Process FTIR
Transfer reaction understanding across scales, from the laboratory to classified plant areas. Läs mer
Reaction Analysis Simplified
In order to understand chemical reactions, chemists must address the following:
- When does the reaction start? When does the reaction stop?
- What are the reaction kinetics and mechanism?
- What is the effect of those transient intermediates?
- Did it react as expected? Did any by-products form and why?
- What happens if reaction temperature, dosing rates, and mixing rates change?
In order to get to the best data and analyze reactions quickly, these are five key areas that ReactIR FTIR spectrometer leverages so that reaction understanding is available for every chemist—expert or not.

Broad Range of In-Situ Probes
Probes are designed to operate over a wide range of conditions to enable the analysis of virtually any type of chemistry:
- Low to high temperature
- Low to high pressure
- Under acidic, basic, caustic, oxidizing, and aqueous conditions
Probe- and flow-based sampling technologies enable scientists to study liquid phase chemistry in batch or continuous setups.

Best-In-Class Performance
From probe to detector to software, ReactIR is optimized for use in the mid-IR "fingerprint" region, resulting in a highly sensitive system for fast and accurate molecular information.
ReactIR directly follows the concentration of key reaction species as they change during the course of the reaction.
Versatile FTIR Spectroscopy

Solutions from Lab to Plant
Small enough to fit in a fume hood, ATEX rated to fit in a plant, and sampling technology to sample any reaction or process. ReactIR can be used to prove that what happens in the plant is what you observed in the lab.
One Click Analytics™
Designed specifically for time-resolved reaction analysis, iC IR software combines a peak picking algorithm with functional group intelligence to drastically reduce analysis time. Läs mer

Reaction Analysis Experts
As a company, METTLER TOLEDO has over 30 years of dedicated reaction analysis experience. This is our focus and our passion. We built this expertise into fit-for-purpose FTIR spectrometers.
ReactIR works in a wide range of chemistries. Find out how scientists gain insight into their reactions and processes in these application areas:
Why Choose ReactIR Over Offline Analysis?
Traditionally, to obtain reaction information, samples are taken for offline analysis using HPLC. For chemistries in which sample removal results in the loss of key information, or are toxic or otherwise hazardous, this procedure is not straightforward. Furthermore, chemists must be present to take the sample and then wait for the results before reaction analysis can begin.
These problems have implications, including:
- The sample may not be representative
- Destruction of intermediate leads to incorrect pathway hypothesis
- Understanding of air-sensitive, toxic, explosive, or pressure systems
- Longer development times due to erroneous data because the reaction changed
- Critical events that impact product or process quality may be missed
ReactIR alleviates these issues and allows scientists to observe intermediates that form in real time without disrupting the reaction.
FTIR Spectrometer FAQs
Is FTIR or Raman better for my application?
Raman and FTIR spectroscopy offer molecular information about the structure and composition of chemical and biological samples. Because of the fundamental principles that govern each technology, both can yield complementary information. However, frequently one technology is a better choice, depending on the nature of the application.
What are FTIR spectrometers used for?
Fourier transform infrared (FTIR) spectrometers are used in both industry and academic laboratories to better understand the molecular structure of materials as well as the kinetics, mechanisms, and pathways in chemical reactions and catalytic cycles. FTIR spectroscopy helps in understanding the structure of individual molecules and the composition of molecular mixtures. FTIR spectroscopy has broad use and applicability in the analysis of molecules important in the pharmaceutical, chemical and polymer industries.
What is FTIR spectroscopy?
Fourier transform infrared (FTIR) is a type of infrared (IR) spectroscopy that has been in existence for several decades now as a valuable tool to interrogate samples of unknown composition. FTIR is one of the most heavily used optical spectroscopy techniques by scientists in academia, government, and the industrial sector. Infrared spectroscopy takes advantage of the fact that atom-to-atom bonds vibrate at specific frequencies.
When energy, comprised of multiple frequencies (such as that from an infrared source), is introduced to these molecular vibrations, an absorption of that infrared energy occurs at that same molecular vibrational frequency. Plotting the intensity of the absorbance across a range of frequencies, yields an infrared spectrum. Furthermore, bonds of different types (e.g., double, triple) and different atoms (e.g, C–O, C–H, C–N, etc.) each have specific vibrational frequencies.
The specificity of these vibrational frequencies can be thought of as a fingerprint of the atom-to-atom bonds that make up a given molecule. This fingerprint then makes it possible to identify molecules or compounds in a mixture and likewise can detect the making and breaking of chemical bonds that occur in a reaction.
What is the difference between IR and FTIR?
FTIR (Fourier transform infrared) is a type of IR (Infrared) spectroscopy, that allows scientists to probe the vibrations of molecules. Infrared Spectroscopy was traditionally a dispersive technique, making use of technology such as a monochromator to scan across the wavelengths of the infrared spectrum. With FTIR, all the wavelengths of light are measured at the same time, using an interferometer. The infrared spectrum is then obtained through a mathematical transformation called a Fourier transform. As all the wavelengths are measured simultaneously, FTIR can collect spectra much faster than scanning techniques.
FTIR Spectrometer Resources
FTIR Spectrometers in Journal Publications
Continuous measurements from infrared spectrometers are used for obtaining reaction profiles to calculate reaction rates. A list of publications from peer-reviewed journals focuses on exciting and novel applications of FTIR spectroscopy. Researchers in both academia and industry employ in-situ mid-FTIR spectrometers to provide comprehensive information and rich experimental data to advance their research.
- Liu, J., Sato, Y., Yang, F., Kukor, A. J., & Hein, J. E. (2022). An Adaptive Auto‐Synthesizer using Online PAT Feedback to Flexibly Perform a Multistep Reaction. Chemistry–Methods, 2(8). doi.org/10.1002/cmtd.202200009
- Malig, T. C., Kumar, A., & Kurita, K. L. (2022). Online and In Situ Monitoring of the Exchange, Transmetalation, and Cross-Coupling of a Negishi Reaction. Organic Process Research & Development, 26(5), 1514–1519. doi: org/10.1021/acs.oprd.2c00081
- Naserifar, S., Kuijpers, P. F., Wojno, S., Kádár, R., Bernin, D., & Hasani, M. (2022). In situ monitoring of cellulose etherification in solution: probing the impact of solvent composition on the synthesis of 3-allyloxy-2-hydroxypropyl-cellulose in aqueous hydroxide systems. Polymer Chemistry, 13(28), 4111–4123. doi.org/10.1039/d2py00231k
- Talicska, C. N., O’Connell, E. C., Ward, H. W., Diaz, A. R., Hardink, M. A., Foley, D. A., Connolly, D., Girard, K. P., & Ljubicic, T. (2022). Process analytical technology (PAT): applications to flow processes for active pharmaceutical ingredient (API) development. Reaction Chemistry & Engineering, 7(6), 1419–1428. doi.org/10.1039/d2re00004k
- Wei, B., Sharland, J. C., Blackmond, D. G., Musaev, D. G., & Davies, H. M. L. (2022). In Situ Kinetic Studies of Rh(II)-Catalyzed C–H Functionalization to Achieve High Catalyst Turnover Numbers. ACS Catalysis, 12(21), 13400–13410. doi.org/10.1021/acscatal.2c04115
- Foth, P. J., Malig, T. C., Yu, H., Bolduc, T. G., Hein, J. E., & Sammis, G. M. (2020). Halide-Accelerated Acyl Fluoride Formation Using Sulfuryl Fluoride. Organic Letters, 22(16), 6682–6686. doi.org/10.1021/acs.orglett.0c02566
- Hu, C., Shores, B. T., Derech, R. A., Testa, C. J., Hermant, P., Wu, W., Shvedova, K., Ramnath, A., Al Ismaili, L. Q., Su, Q., Sayin, R., Born, S. C., Takizawa, B., O’Connor, T. F., Yang, X., Ramanujam, S., & Mascia, S. (2020). Continuous reactive crystallization of an API in PFR-CSTR cascade with in-line PATs. Reaction Chemistry & Engineering, 5(10), 1950–1962. doi.org/10.1039/d0re00216j