October 24th 2024
A recent study used spectroscopic techniques to study the mineral composition of sedimentary rocks in Texas.
The Grand Review I: Why Do Different Functional Groups Have Different Peak Positions?
November 1st 2020Articles in this column have addressed five main areas: theory, functional groups containing the C-H bond, those containing the C-O bond, those with the C=O bond, and those with organic nitrogen compounds. Here, we review the concepts.
Insights Toward Standardization of the Analysis of Microplastics by Infrared Microscopy
August 1st 2020Here we conduct an evaluation of significant operational parameters of IR microscopy for accurately determining the size of microplastics, with the overarching goal of outlining performance parameters that will help in the standardization of microplastics analysis.
Organic Nitrogen Compounds VIII: Imides
March 1st 2020Here, we continue our examination of the infrared (IR) spectra of organic nitrogen compounds with imides, which are a common chemical intermediate. IR can be used not only to identify imides, but also to distinguish between straight chain and cyclic imides. We explain how.
Analysis of FDA Infrared 483 Citations: Have You a Data Integrity Problem?
September 1st 2019Analysis of FDA Form 483 observations and warning letters for infrared spectrometers reveals a range of data integrity problems and a lack of laboratory procedures for the technique. Is your laboratory in the same situation?
Advancing Biomedical Research with New Infrared and Raman Microscopy Techniques
June 10th 2019Significant progress is being made to harness the power of spectroscopy technique for medical research. An ongoing challenge, and area of development, in this effort, is to “see” more and more detail about biological activity, even within individual cells. Ji-Xin Cheng, a professor of biomedical engineering at Boston University, is advancing such work, by developing techniques like midinfrared photothermal (MIP) imaging and Raman spectromicroscopy. Cheng is the 2019 winner of the Ellis R. Lippincott Award, which is awarded annually by the Optical Society, the Coblentz Society, and the Society for Applied Spectroscopy, to an individual who has made significant contributions to the field of vibrational spectroscopy. Here, Cheng speaks to us about those techniques.
The Use of Portable Near-Infrared Spectroscopy for Authenticating Cardiovascular Medicines
May 1st 2019Portable NIR spectroscopy is demonstrated as a rapid and mobile analysis method for authenticating cardiovascular medicines in critical situations, and to indicate whether formulations are counterfeit or substandard.
The C=O Bond, Part VII: Aromatic Esters, Organic Carbonates, and More of the Rule of Three
September 1st 2018Aromatic esters follow the ester Rule of Three, but each of these three peak positions is different for saturated and aromatic esters, which makes them easy to distinguish. Organic carbonates are structurally similar to esters and follow their own Rule of Three.
The Carbonyl Group, Part V: Carboxylates—Coming Clean
May 1st 2018Carboxylates are made by reacting carboxylic acids with strong bases such as inorganic hydroxides. Carboxylates contain two unique carbon–oxygen “bond and half” linkages that coordinate with a metal ion to give two strong infrared peaks, which make them easy to see.
The C=O Bond, Part II: Aldehydes
November 1st 2017Aldehydes feature a unique “lone hydrogen” atom, giving rise to unique C-H stretching and bending peaks, making them easy to spot. In this installment, a new feature is also presented, “IR Spectral Interpretation Review,” where key concepts from past columns are presented for those new to the column and for readers who need a refresher.
Detecting Blood on Fabrics: Infrared Diffuse Reflectance Versus Attenuated Total Reflectance FT-IR
August 14th 2017In forensic science, the detection of blood on fabric is a very useful tool. Therefore, it is important that the methods used for detecting blood be as accurate as possible. Michael L. Myrick and Stephen L. Morgan, both professors in the Department of Chemistry and Biochemistry at the University of South Carolina, have been investigating the use of infrared (IR) spectroscopy for this purpose, including comparing the effectiveness of infrared diffuse reflectance versus attenuated total reflectance Fourier-transform IR (ATR FT-IR). They recently spoke to Spectroscopy about their recent studies and the critical questions they have been addressing in how IR spectroscopy is used in forensic science.
Tracking Microplastics in the Environment via FT-IR Microscopy
August 1st 2017Microplastics from clothing, abrasive action on plastics, or engineered microbeads as found in some exfoliating cosmetics are showing up in many environmental systems. FT-IR microscopy is a useful tool in the analysis of microplastics, providing visual information, particle counts, and particle identification.