Infrared (IR) Spectroscopy

In this tutorial, Thomas G. Mayerhöfer and Jürgen Popp introduce complex-valued chemometrics as a more physically grounded alternative to traditional intensity-based spectroscopy measurement methods. By incorporating both the real and imaginary parts of the complex refractive index of a sample, this approach preserves phase information and improves linearity with sample analyte concentration. The result is more robust and interpretable multivariate models, especially in systems affected by nonlinear effects or strong solvent and analyte interactions.

A recent study published in the journal Food Chemistry explored Brazil’s cachaça industry, focusing on a new analytical method that can confirm the geographic origin of cachaças from the Brejo Paraibano region in Brazil.

Explore advancements in infrared spectroscopy and insights from Brian Smith, a key columnist, on the future of this evolving field.

In this Icons of Spectroscopy article, Executive Editor Jerome Workman Jr. delves into the life and impact of Bruce Kowalski, an analytical chemist whose major contributions to chemometrics helped establish the field of applying advanced quantitative and qualitative mathematics to extract meaningful chemical information from complex datasets. Kowalski’s visionary approach to chemical data analysis, education, and software development has transformed the landscape of modern analytical chemistry for academia and industry.

Researchers in Rome used advanced spectroscopic techniques to probe the mineralogy of the CM2 carbonaceous chondrite NWA 12184. This revealed the effects of space weathering and provided insights into C-type asteroid evolution.

In the final part of this three-part interview, Ayanjeet Ghosh of the University of Alabama and Rohit Bhargava of the University of Illinois Urbana-Champaign talk about the key performance metrics they used to evaluate their model, and what the future of neurodegenerative disease research looks like.

A new review by researchers from IIT Delhi and the University of Queensland highlights how Terahertz (THz) and low-wavenumber Raman (THz-Raman) spectroscopy are advancing quality control and efficiency in pharmaceuticals, agriculture, and mineral industries. These powerful non-invasive tools enable detailed multi-parameter sensing, offering deeper insight at the molecular level.

In the second part of this three-part interview, Ayanjeet Ghosh of the University of Alabama and Rohit Bhargava of the University of Illinois Urbana-Champaign discuss how machine learning (ML) is used in data analysis and go into more detail about the model they developed in their study.

A team of international researchers has developed a faster, more accurate method to analyze soil carbon fractions using mid-infrared spectroscopy and deep learning. Their approach preserves the chemical balance of soil organic carbon components, paving the way for improved climate models and sustainable land management.

In the first part of this three-part interview, Ayanjeet Ghosh of the University of Alabama and Rohit Bhargava of the University of Illinois Urbana-Champaign discuss their interest in using discrete frequency infrared (IR) imaging to analyze protein secondary structures.

Researchers at the Sinopec Research Institute have developed a novel method using virtually generated mid-infrared spectra to accurately quantify plastic blends, offering a faster, scalable solution for recycling and environmental monitoring.

Scientists at the University of Barcelona have developed a fast and reliable way to identify natural, treated, and synthetic rubies and sapphires using Fourier-transform infrared (FT-IR) spectroscopy. Their study reveals unique spectral fingerprints for different gemstone types, offering a powerful tool in the fight against gem fraud.

A historical and technical overview from the Gemological Institute of America (GIA) explores how advanced scientific instruments—particularly spectroscopic methods—have transformed gem identification. From refractometers to modern spectrophotometers, this deep dive highlights the evolving challenges and solutions in gem testing.

A new study in the Journal of Food Composition and Analysis showcases high-performance detection using artificial intelligence and spectroscopy.

New research from the Gemological Institute of America highlights the essential role of infrared spectroscopy in identifying gemstones, detecting treatments, and distinguishing natural from synthetic gems. The technique’s precision and non-destructive nature have made it an indispensable tool in modern gemology.

In this “Icons of Spectroscopy” column, Spectroscopy Executive Editor Jerome Workman, Jr. explores the life and contributions of Albert Abraham Michelson, a graduate of the United States Naval Academy, who showed early brilliance in physics and mathematics, eventually resulting in a teaching position at the Academy and the Nobel Prize in Physics in 1907.

Researchers from the University of Nevada, Reno, have conducted the most comprehensive subsurface analysis of Hawaiian shield basalts to date, using advanced spectroscopic and geochemical techniques to reveal short-lived hydrothermal alteration processes and establish a new foundation for future volcanic and geothermal studies.

A new study led by Ayanjeet Ghosh of the University of Alabama presents a transformative approach to analyzing infrared (IR) imaging data, with promising implications for neurodegenerative disease research.

Carbonyl containing functional groups are strong infrared absorbers and a number of them are easy to identify by infrared spectroscopy. Here, we will review the spectra of ketone and carboxylic acids.

In this interview, S. Michael Angel, a consultant on the SuperCam team, explains how the instrument analyzes Martian rocks and what it reveals about Mars’ geology and potential for past life.

Macarena Garcia Marin, an astrophysicist and instrument scientist for the European Space Agency, highlights the role spectroscopy techniques have played in the pivotal research done on the James Webb Telescope since its launch in 2021.

A study from Chinese researchers demonstrates how combining satellite imagery, land use data, and machine learning can improve pollution monitoring in fast-changing urban rivers. The study focuses on non-optically active pollutants in the Weihe River Basin and showcases promising results for remote, data-driven water quality assessments.

Researchers from Université de Tours have shown that serum mid-infrared spectroscopy (MIRS) may serve as a promising prognostic tool for identifying high-risk metastatic colorectal cancer patients undergoing first-line bevacizumab-based chemotherapy.

New research highlights how remote satellite sensing technologies are changing the way scientists monitor inland water quality, offering powerful tools for tracking pollutants, analyzing ecological health, and supporting environmental policies across the globe.

A recent study conducted by scientists in Brazil saw the development of a quick, non-invasive method to diagnose endometriosis.

Modern remote sensing technologies have evolved from coarse-resolution multispectral sensors like MODIS and MERIS to high-resolution, multi-band systems such as Sentinel-2 MSI, Landsat OLI, and UAV-mounted spectrometers. These advancements provide greater spectral and spatial detail, enabling precise monitoring of environmental, agricultural, and land-use dynamics.

This article shows the benefits and ease with which mid-infrared testing can reveal supply change mismanagement events and help to quickly identify and correct mishaps.

A leading-edge review led by researchers at Oak Ridge National Laboratory and MIT explores how artificial intelligence is revolutionizing the study of molecular vibrations and phonon dynamics. From infrared and Raman spectroscopy to neutron and X-ray scattering, AI is transforming how scientists interpret vibrational spectra and predict material behaviors.