Spectroscopy Interviews

The use of engineered nanoparticles (ENPs) in various applications and consumer products continues to increase, and these nanoparticles require thorough characterization for proper environmental risk assessment. James Ranville, a professor at the Colorado School of Mines, in Golden, Colorado, has been studying colloids and and particles in environmental processes and developing methods to collect and analyze colloids from rivers, reservoirs, mountain streams, soil solutions, and ground waters. He spoke with us about his work using field-flow fractionation–inductively coupled plasma mass spectrometry (FFF-ICP-MS) and ICP-MS for the detection of engineered nanoparticles in environmental samples.

Currently, there is significant interest in using vibrational spectroscopy techniques for a variety of biomedical applications, and the methods are showing good promise. Karen Faulds, a professor at the University of Strathclyde in Glasgow, has been investigating the application of surface-enhanced Raman spectroscopy (SERS) to the detection of disease pathogens, such as meningitis, and to distinguish related pathogens in a complex matrix. Faulds is the 2016 recipient of the Coblentz Society’s Craver Award, which recognizes the efforts of young professional spectroscopists who have made significant contributions in applied analytical vibrational spectroscopy. This interview is part of a series of interviews with the winners of awards that will be presented at the SciX 2016 conference.

Laser-ablation inductively coupled plasma–mass spectrometry (LA-ICP-MS) is well suited for highly sensitive elemental and isotopic analysis of solid samples. In this technique, a laser beam ablates the sample and generates fine particles that are then transported to the ICP-MS system for rapid elemental analysis. Detlef Günther is Professor for Trace Element and Micro Analysis and Vice President Research and Corporate Relations for ETH Zurich, and he and his group use LA-ICP-MS for two- and three-dimensional imaging of geological samples such as rocks and meteorites. He recently spoke to us about this research.

Spectroscopy has played a significant role in the Mars expeditions, including the confirmation of the former presence of water on the Red Planet. Raymond Arvidson, the James S. McDonnell Distinguished University Professor at Washington University in Saint Louis, Missouri, is involved with the various National Aeronautics and Space Administration (NASA) missions to Mars and the spectroscopy incorporated in the instruments sent there. Here, Arvidson discusses those techniques, including a hyperspectral imaging system, an emission spectrometer, and an X-ray spectrometer, and what the results of the missions indicate about Mars so far.

Total reflection x-ray fluorescence (TXRF) spectrometry is an energy-dispersive x-ray technique that is used for elemental and chemical analysis, and is especially suitable for small-sample analyses. Ursula Fittschen, an assistant professor at Washington State University, is working on elemental microscopy and micro analysis. She has been using TXRF to analyze stainless steel metal release, and also airborne silver nanoparticles (NPs) from fabrics. Here, she describes the advantages and challenges of this technique.

The isotopic profile of a material refers to the ratios of the stable isotopes of elements contained within, such as 2H/1H, 13C/12C, and 18O/16O. Biological, chemical, and physical processes cause variations in the ratios of stable isotopes; analysis of a material for its distinctive isotopic signature can thus be used to reveal information about its history. Isotope ratio mass spectrometry (IRMS) is a technique used to measure the relative abundance of isotopes in materials. Forensic investigators have used IRMS to measure a variety of materials, such as drugs, explosives, food, and human remains. In a recent web seminar, Lesley Chesson, the president of IsoForensics, Inc., explained how IRMS works and discussed the use of IRMS in forensic science, illustrating her discussion with several case examples.

A wide variety of processes occur at biological interfaces, such as those between drugs and membranes, metal ions and membranes, and water and membranes. Paul S. Cremer, the J. Lloyd Huck Chair in Natural Sciences in the Department of Chemistry at Penn State, is the recipient of the 2016 ANACHEM Award, and he and his group study these processes using various novel spectroscopy and microfluidic approaches.. 

In recent years, Raman spectroscopy has been applied to process monitoring and control applications in a wide range of application fields, including bioprocessing, pharmaceuticals, food, oil and gas, and oceanography. Brian Marquardt, cofounder and CEO of MarqMetrix, Inc., and director and senior principal engineer with the Center for Process Analysis and Control in the Applied Physics Laboratory at the University of Washington, has more than 15 years of experience with such applications and recently spoke with us about his research.

Understanding electron- and energy-transfer processes in nanoscale systems is critical both for investigating fundamental energy redistribution mechanisms in nanoscopic media and for developing new devices based on these systems. Ken L. Knappenberger is the recipient of the 2016 Coblentz Award and is an associate professor in the Department of Chemistry and Biochemistry at Florida State University, and he and his group study these processes in nanoscale assemblies by developing and implementing novel optical spectroscopy approaches. He recently spoke to us about this work.

Inductively coupled plasma (ICP) techniques, such as ICP coupled with mass spectrometry (ICP-MS) and ICP–optical emission spectroscopy (OES), have seen a lot of growth in recent years for the direct analysis of organic samples such as petroleum and biofuels. José-Luis Todolí, a professor at the University of Alicante in Spain, has conducted several studies in this area, including the elemental determination of metals in bioethanol using ICP-OES, and the use of a torch integrated sample introduction system as well as ICP-MS to analyze petroleum products and biofuels. He recently spoke to us about this work and other projects involving ICP techniques that his group is focused on.

Surface-enhanced Raman spectroscopy (SERS) has made significant progress in recent years (1), and its application to biomedical studies is of particular interest. Colin Campbell of the University of Edinburgh is taking the biomedical application of SERS to a new level by using the technique to make spatially resolved measurements in live three-dimensional (3D) cell cultures to determine the response to drugs during drug discovery operations. For this work, Campbell received a FACSS Innovation Award at the SciX 2015 conference last October. This interview is part of the Spectroscopy¬–SciX interview series.

Novel optical imaging methods have opened new frontiers in chemical and biological discovery because they are minimally intrusive, requiring virtually no contact with the sample. Ning Fang, who is an associate professor of chemistry at Georgia State University, specializes in single-molecule and nanoparticle imaging, bioanalytical chemistry, and biophysics. He recently spoke to us about his work with far-field optical imaging methods for visualizing the dynamics of biomolecules and nanoparticle probes.

Near-infrared (NIR) spectroscopy offers quick analysis with no sample preparation for many fields, but it is particularly popular for process monitoring, materials science, and medical uses. NIR has also seen applications in agriculture from the very start of the technique, but new instrument capabilities are poised to offer even more to that field. Benoît Igne, a principal scientist at GlaxoSmithKline in King of Prussia, Pennsylvania, recently spoke to us about his work using NIR and areas where he thinks the technique has growth potential, specifically process analytical technology and agriculture.

Economically motivated food adulteration is a problem around the world. The 2013 horsemeat scandal in Europe, in which horsemeat was substituted for beef and pork, did not cause serious health problems, but certainly upset many consumers and led to a desire for increased quality control over meat products. İsmail Hakkı Boyaci of the Food Research Center at Hacettepe University, in Ankara, Turkey, has developed a method using laser-induced breakdown spectroscopy (LIBS) to detect meat adulteration. He recently spoke to us about this work.

Vibrational spectroscopic techniques such as Raman spectroscopy have taken on increasingly important roles in point-of-care testing, spectral histopathology, and rapid in vivo diagnostics. Nick Stone is a Professor of Biomedical Imaging and Biosensing at the University of Exeter, and he and his group use Raman spectroscopy for measuring changes in the molecular constituents of cells and tissues as disease develops. He recently spoke to us about this work.

Quantum cascade lasers have been gaining increasing attention as their capabilities are being demonstrated in a range of applications. One recent advance is the development of a miniaturized QCL, which when used as a light source, enables mid-infrared (mid-IR) scanning speeds much faster than those of conventional Fourier-transform IR (FT-IR). Ralf Ostendorf of the Fraunhofer Institute for Applied Solid State Physics (IAF) in Freiburg, Germany, recently spoke to Spectroscopy about this work.

Matthew Baker of the University of Strathclyde in Glasgow, Scotland, has been using infrared spectroscopy for the analysis of biological samples. The noninvasive procedure allows for the rapid detection of diseases and provides an opportunity for early administration of a therapeutic strategy, when the treatment is most effective. Spectroscopy spoke with him about his work in this area using attenuated total reflection (ATR) and ATR combined with Fourier transform infrared (FT-IR) spectroscopy.

Air quality is a global concern, but even more so for urban areas and poor countries. The pollution in the air goes directly into our lungs, which makes monitoring the particulates and various levels of pollution a major concern. Johan Boman of the Department of Chemistry & Molecular Biology at University of Gothenburg has been studying the air quality in several different regions using energy dispersive X-ray fluorescence (EDXRF) and total reflection X-ray fluorescence (TXRF). Here, he discusses the challenges faced in this research and plans for future studies.

Inductively coupled plasma–mass spectrometry (ICP-MS) has become a successful approach for fast, multielemental analysis, and analysts are applying it to a wide range of analyses, including geochemical, environmental, forensic, and medical studies. Uwe Karst is a Professor and Chair of the Analytical Chemistry Department at the University of Münster in Germany, and he and his group use ICP-MS for applications such as analyzing magnetic resonance imaging (MRI) contrast agents in river water, speciation analysis in a study of a disease related to renal failure, and examining the distribution of a labeling compound in mouse tumor cells and macrophages. He recently spoke to us about this work.

Inductively coupled plasma (ICP) sources have been around for so long that most scientists don’t even question their capability to get the job done. However, an ion source for elemental mass spectrometry (MS) has been developed that offers different benefits compared to ICP sources: the liquid sampling-atmospheric pressure glow discharge (LS-APGD) ionization source, which features small sample volumes, low uptake rates and waste, and low operating power.

Imaging techniques using vibrational spectroscopy, mass spectrometry (MS), and atomic force microscopy have all been advancing and gaining momentum in recent years. There is great potential power in these imaging techniques, particularly in the biomedical field. Thomas Bocklitz of at the Friedrich-Schiller-University Jena is working to better harness the power of these techniques by combining them.

Laser-induced breakdown spectroscopy (LIBS) is an ideal technique for elemental analysis in industrial applications because of its fast response and high sensitivity, and its ability to be used for real-time, noncontact analysis.

Diffuse reflectance is a well-known sampling technique in mid-infrared (mid-IR) and near-IR spectroscopy. Despite its significance, however, the underlying mechanism of the technique is not well understood-particularly in mid-IR diffuse reflectance. Eric B. Brauns, an Associate Professor at the University of Idaho, has developed an instrument capable of studying the mechanism, using time-resolved measurements. Brauns won the 2015 Applied Spectroscopy William F. Meggers Award for this work (1). He recently spoke with Spectroscopy about his award-winning paper and what it means for the field.