Molecular Spectroscopy

Raman spectroscopy is a valuable process analytical technology (PAT) for many applications across multiple industries, as a result of its many advantages, such as molecular specificity, ability to be directly coupled to a reaction vessel, and compatibility with solids, liquids, gases, and turbid media.

New Raman spectroscopy applications are emerging in non-traditional fields because of advances in easy-to-use commercial Raman spectroscopy instrumentation. With improvements in lasers, optics, and detectors, Raman spectroscopy has developed into a powerful measurement solution for manufacturing and quality control applications.

Low frequency Raman scattering measurements can be used to predict physical properties of polymers and the crystalline polymorphic form of active pharmaceutical ingredients (APIs). These measurements are made by recording the Stokes and anti-Stokes side of the laser line with the laser centered on the detector. Spectra of polyethylene and linear alkanes were recorded down to 4 cm-1.

Spectroscopy Magazine spoke with Claudia Conti about her work in micro-SORS.

Spectroscopy Magazine sat down with Kay Sowoidnich to talk about how his group has demonstrated the potential of shifted-excitation Raman difference spectroscopy (SERDS) as an efficient tool for soil nutrient analysis.

In general, many Raman measurements suffer from fluorescence, which forces the use of longer excitation wavelength (lower photon energy) lasers to prevent the fluorescence signal from overwhelming the Raman signal. However, this results in reduced sensitivity of low-cost silicon CCD detectors at higher wavenumbers, making it difficult (or impossible) to observe the “stretch” portion of the Raman spectra.

The Oxigraf state-of-the-art Oxygen Deficiency Monitor, the Model O2iM, is a responsive, accurate, and reliable safety monitor for oxygen displacement monitoring in quantum computer laboratory, MRI, NMR, and liquid nitrogen and helium storage facilities. Our reliable solid-state sensor does not require routine maintenance or factory calibration, and the O2iM is equipped with an automatic, programmable auto-calibration system. The system easily interfaces with alarm system and building management systems.

Markita Landry, the winner of the 2020 Emerging Leader in Molecular Spectroscopy Award, works at the intersection of single-molecule biophysics and nanomaterial-polymer science to develop new tools for understanding biological systems.

This application note demonstrates determining the correct orientation of the polarizer for these measurements and illustrates the importance of polarized measurements in specific examples.

The concentration of ethanol in hand sanitizer was determined using a calibration developed with an automated ATR sampling accessory.

A Raman spectrometer’s spectral resolution is determined by its spectral dispersion in conjunction with the entrance slit width. We explain the instrument design parameters involved.

This study describes how Raman imaging and correlative Raman scanning electron (RISE) microscopy can characterize and visualize layer numbers in 2D MoS2 and WSe2 samples.

In the past decades, we have witnessed the evolution of imaging technologies based on vibrational spectroscopy. In particular, the technical developments in Raman, coherent anti-Stokes Raman spectroscopy (CARS), and stimulated Raman scattering (SRS) microscopy allow researchers to gain new insights in biological, medical, and pharmaceutical studies.

Portable spectroscopic instruments have not had significant visibility within the scientific community compared with, for instance, the current generation of high-performance laboratory mass spectrometers.

Forensic traces are physical remnants of past events that provide critical information for criminal and civil investigations and adjudications. The scientific examination of traces is an incredibly valuable tool for forensic investigations, because the skilled interpretation of traces yields factual answers to a range of pertinent questions.

An ongoing challenge within the forensic science community is the development of consistent report and testimony language that conveys results in a meaningful manner.

In celebration of Spectroscopy’s 35th Anniversary, leading spectroscopists discuss important issues and challenges in analytical spectroscopy.

In celebration of Spectroscopy’s 35th Anniversary, leading spectroscopists discuss important issues and challenges in analytical spectroscopy.

In celebration of Spectroscopy’s 35th Anniversary, leading spectroscopists discuss important issues and challenges in analytical spectroscopy.

In celebration of Spectroscopy’s 35th Anniversary, leading experts discuss important issues and challenges in analytical spectroscopy.

In celebration of Spectroscopy’s 35th Anniversary, leading experts discuss important issues and challenges in analytical spectroscopy.

In celebration of Spectroscopy’s 35th Anniversary, leading experts discuss important issues and challenges in analytical spectroscopy.

In celebration of Spectroscopy’s 35th Anniversary, leading experts discuss important issues and challenges in analytical spectroscopy.

In celebration of Spectroscopy’s 35th Anniversary, leading experts discuss important issues and challenges in analytical spectroscopy.

Raman spectroscopy and imaging techniques are well suited for the characterization of surfaces, interfaces, and coatings to support research, development, and manufacturing of medical devices. Here, we describe applications in surface modifications and coatings, differentiation of drug polymorphs, degradation of biomaterials, and forensic identification of unknown materials.

Of the 78 million tons of plastic packaging manufactured every year, approximately one-third ends up in the ocean, the air, and most foods and beverages. To monitor the proliferation of these plastics, an ultrasonic capture method is demonstrated that produces a 1500-fold enhancement of Raman signals of microplastics in water.

A Raman study of vitamin C, also known as ascorbic acid, is conducted at high pressure to determine phase changes and crystal symmetry through spectral interpretation.

Because of their corrosive properties, corrosive lipids are challenging to analyze by ATR-FT-IR. Repeated and prolonged analysis can damage many ATR crystals. Diamond ATR is a better choice for such applications than other ATR crystal materials like ZnSe and Ge. This application note examines a corrosive liquid as it becomes progressively more concentrated using diamond ATR.

Raman spectroscopy’s high analytical selectivity and insensitivity to water is well suited for process monitoring in biotechnology. Here we explore the fermentation of glucose, a common feedstock, with a commonly used microorganism, yeast. Applying multivariate tools, we can monitor the main reactants and products with high sensitivity: glucose, ethanol, and carbon dioxide.