Spectroscopy-09-01-2016

Adhesives are a group of materials that are found extensively in manufacturing and production industries and are of great interest for quality control and failure analysis. This paper discusses the use of an array detector in conjunction with ultrafast mapping to produce kinetic chemical imaging to monitor the curing process in a two-part epoxy resin. This technique allows for simultaneous analysis of both the kinetics of the epoxy reaction along with the spatial information of the reaction. This kinetico-spatial information gives insight about localized domains that form when the epoxy is mixed and how the reaction progresses.

Photoluminescence can provide information about the composition and solid state structure of a material. The high spectral resolution of a Raman spectrometer can be useful in performing photoluminescence spectroscopy of solid state materials, particularly when the emission spectra consist of narrow bands or even lines. Having the capability to perform photoluminescence and Raman spectroscopies simultaneously with the same instrument is advantageous, especially when studying 2D crystals. When used to perform photoluminescence spectroscopy, the Raman spectrometer becomes two instruments in one.

In April 2016, the FDA issued a draft guidance for industry on data integrity and compliance with cGMP. What does this mean for the laboratory?

The development of novel, nondestructive technologies for rapid analysis of evidence discovered at crime scenes is pertinent to our criminal justice system to solve the millions of violent crimes that occur each year. Without a witness, establishing the precise timeline of a crime is difficult. Therefore, technologies based on sensitive, nondestructive techniques are needed to evaluate evidence and create such a timeline. We propose the use of Raman spectroscopy to analyze the age of bloodstains for potential use as a forensics tool. Previous studies have revealed Raman spectroscopy is sensitive to changes in blood analyte concentration and different oxidative states of hemoglobin. Raman spectroscopy could allow for rapid comparison of spectra from blood stains of unknown age to spectra of known age with high temporal accuracy. Though further investigation into other substrates and biochemical components should be performed, our study reveals Raman spectroscopy has the potential to accurately and nondestructively determine the age of a bloodstain for use in criminal investigations.

With the theoretical background of benzene analysis laid out in part 1 of this series, we now know what fundamental, overtone, and combination bands look like. Here, I show that the benzene fingers are a series of overtone and combination bands that can be used to distinguish substituted benzene rings from each other when other methods do not work. I review the benzene finger patterns for mono-, ortho-, meta-, and para- substituted benzene rings, and describe an easy mnemonic in which you use your fingers to help you remember the patterns.

Brian Marquardt discuses his work applying Raman spectroscopy to process monitoring and control applications in a wide range of fields.

Matthew J. Baker, the winner of Spectroscopy’s inaugural Emerging Leader in Molecular Spectroscopy Award, is passionate about solving clinical problems with vibrational spectroscopy.

Click the title above to open the Spectroscopy September 2016 regular issue, Vol 31 No 9, in an interactive PDF format.