Interview of the Month

 

Analyzing Art with Lasers
Lasers have many different scientific uses. Some analytical scientists are advancing the use of laser-based techniques to analyze works of art and other ancient artifacts. Laser-ablation surface-enhanced Raman microspectroscopy (LA-SERS) can analyze art and artifacts to accurately identify the various components inside them. Spectroscopy recently spoke with Pablo Londero, an Associate Conservation Scientist at the Institute for the Preservation of Cultural Heritage (IPCH) at Yale University, and Marco Leona, the head of scientific research at the Metropolitan Museum of Art, about their work in this area.

 

More interviews

FT-IR

Macro ATR-FT-IR Spectroscopic Imaging of Dynamic Processes

By James A. Kimber, Sergei G. Kazarian

Macro attenuated total reflection FT-IR spectroscopic imaging is a powerful and underutilized tool. This article presents an overview of approaches and opportunities for using this method to study dynamic processes such as diffusion, sorption, crystallization, and dissolution.

Resonance-Enhanced Nanoscale IR Spectroscopy of Ultrathin Films and Monolayers on Metals

By Feng Lu, Craig B. Prater, Kevin Kjoller, Curtis Marcott, Mingzhou Jin, Mikhail A. Belkin, Honghua Yang

Resonance-enhanced atomic force microscopy (AFM)–infrared (IR) is a new technique that couples an atomic force microscope with a pulsed tunable IR laser source to provide high spatial resolution chemical analysis of samples as thin as a monolayer. The AFM probe tip acts as a small local detector of the thermal expansion of the sample caused by the absorption of the monochromatic IR radiation.

Identifying Organic Impurities in Counterfeit and Illicit Tobacco Using Portable ATR-FT-IR Spectroscopy

By David Osselton, Sulaf Assi, Phil Moorey, Paul Kneller

Counterfeit and illicit tobacco may contain potentially toxic organic impurities that result in adverse health effects to the consumer. The aim of this work was to investigate the feasibility of the identification of organic impurities in counterfeit or illicit tobacco using attenuated total reflectance-Fourier transform infrared (ATR-FT-IR) spectroscopy.

Identifying Synthetic Designer Drugs Using FT-IR, Raman, and GC–IR

By W. Jalenak, M. Bradley, S. Lowry

Law enforcement relies upon "schedules" or lists of controlled substances. In an attempt to circumvent the law, clandestine laboratories produce synthetic designer drugs that are chemically related to a controlled substance, but are different enough to raise legal issues with prosecution.

Measuring Orientation in Polymer Films

By Richard Spragg

The mechanical properties of polymer films such as tensile strength and resistance to tearing depend strongly on the orientation of the polymer chains. Fourier transform infrared (FT-IR) spectroscopy can be used to measure the degree of orientation both within the plane of the film and normal to it.

Raman

Improving PAT for Biologics

By Cynthia Challener, PhD

Implementing process analytical technology for bioprocessing presents unique challenges, but the recent emphasis on establishing a thorough understanding of the manufacturing process is a key enabler of PAT approaches.

Raman Imaging of Live Cells

By Spectroscopy Editors

Raman microscopy is a promising technique for visualizing the distribution of molecules in cells. However, along with the benefits come challenges. This interview with Katsumasa Fujita, an associate professor in the Department of Applied Physics at Osaka University in Osaka, Japan, discusses his use of this technique for the imaging of live cells.

Sequentially Shifted Excitation Raman Spectroscopy

By Kent L. Wise, John B. Cooper, Richard W. Jones, Sarah Marshall

A method for removing fluorescence-induced backgrounds from Raman spectra using sequentially shifted excitation (SSE) is described. The method uses a temperature-tuned, distributed Bragg reflector diode laser to produce the multiple excitation spectra required to implement the SSE algorithm. Examples applying the SSE method to analysis of motor oils and edible oils are given.

Improving Drug Formulation with Raman and IR Spectroscopy

By Spectroscopy Editors

The physicochemical properties of drugs are often very diverse and challenging to analyze. Spectroscopy recently spoke with Dr. Lynne Taylor of the Department of Industrial and Physical Pharmacy at Purdue University, and the 2014 Coblentz Society Craver Award winner, about her on-going research using Raman and IR spectroscopy to study drugs and drug excipients - and the interactions of the two.

The Use of Portable and Handheld Raman Spectroscopy for Forensic Investigations

By Katherine A. Bakeev, Robert Thomas

The Raman technique is gaining widespread acceptance as an investigative tool for forensic applications.

UV-vis

Overview of High-Efficiency Transmission Gratings for Molecular Spectroscopy

By Thomas Rasmussen

This article provides a basic overview of the capabilities of transmission gratings optimized for molecular spectroscopy.

Scattering Impact Analysis and Correction for Leaf Biochemical Parameter Estimation Using Vis–NIR Spectroscopy

By Guangjun Zhang, Qianxuan Zhang, Qingbo Li

Simulated leaf spectral data were generated to analyze scattering impact and then compared to experimental data to validate the conclusions of the simulation.

Pittcon 2011 New Product Review

By Howard Mark

Our yearly review of the hottest products at Pittcon

An Integration of Modified Uninformative Variable Elimination and Wavelet Packet Transform for Variable Selection

By Di Wu, Yong He, Xiaojing Chen

The wavelet packet transform (WPT) combined with the modified uninformative variable elimination (MUVE) method (WPT–MUVE) is proposed to select variables for multivariate calibration of spectral data.

Analysis of Fructose, Glycine, and Triglycine Using HPLC UV-vis Detection and Evaporative Light-Scattering Detection

By R. Wijntje, A.B. de Haan, H.A.J.M. Bevers

The development of a method for the simultaneous determination of glycine, triglycine and fructose using UV–vis and evaporative light-scattering detection (ELSD) is described. This was necessary as part of a research project dealing with the recovery of functional peptides from aqueous streams on an industrial scale using adsorption or related technologies. Fructose is barely detectable by UV–vis as it lacks detectable functionalities, while glycine and triglycine are both UV–vis sensitive. An NH2 phase was chosen as a column and separation was obtained within seven minutes on a 250 X 4.6 mm column. Limits of detection are approximately 40 mg fructose/L, 4 mg glycine/L and 0.05 mg triglycine/L. Calibration functions are linear in a range of 40–1400 mg/L for fructose, 5–200 mg/L for glycine and 0.5–70 mg/L for triglycine.

Peer-Reviewed Articles


Sequentially Shifted Excitation Raman Spectroscopy
By Kent L. Wise, John B. Cooper, Richard W. Jones, Sarah Marshall
A method for removing fluorescence-induced backgrounds from Raman spectra using sequentially shifted excitation (SSE) is described. The method uses a temperature-tuned, distributed Bragg reflector diode laser to produce the multiple excitation spectra required to implement the SSE algorithm. Examples applying the SSE method to analysis of motor oils and edible oils are given.
 

Macro ATR-FT-IR Spectroscopic Imaging of Dynamic Processes
By James A. Kimber, Sergei G. Kazarian
Macro attenuated total reflection FT-IR spectroscopic imaging is a powerful and underutilized tool. This article presents an overview of approaches and opportunities for using this method to study dynamic processes such as diffusion, sorption, crystallization, and dissolution.

 

Sulfobutyl Ether-β-Cyclodextrin–Assisted Fluorescence Spectroscopy for Determination of L-Amlodipine in Tablets
By Jiaqi Xie, Shenzhi Lai, Xiaoming Chen, Xiaoming Deng, Lin Yang
This study describes a validated spectrofluorometric method for the analysis of L-amlodipine in tablets.

 

How Trace Elemental Analysis Provides Important Insight into Wine Chemistry
By Hildegarde Heymann, Helene Hopfer, Jenny Nelson, Susan E. Ebeler, Thomas S. Collins
Examples are shown that highlight how elemental fingerprinting could provide valuable information about the geographical origin of a food or beverage as well as how different steps in the production of wines impact their elemental composition.

 

More Peer-Reviewed Articles

News

Nominations Sought for AOAC Awards

AOAC International is seeking nominations for the Harvey W. Wiley Award and for recognition as a Fellow of AOAC International.

2015 Gold Medal Award Nominations Deadline is Jan. 5, 2015

Nominations are being sought for the 2015 Gold Medal Award of the New York Section of the Society for Applied Spectroscopy.

Ellen V. Miseo Joins Spectroscopy's Editorial Advisory Board

Spectroscopy magazine is pleased to announce the addition of Ellen V. Miseo to its editorial advisory board.

ICP/ICP-MS

Simplifying Mixed-Food Microwave Sample Preparation for ICP-MS Analysis

By David Gunn

Low-level analysis of food matrices has placed a demand on manufacturers, testing laboratories, and instrumentation vendors worldwide. Stricter regulations, better analytical instrumentation, and greatly improved sample preparation (preanalytical) techniques have focused efforts to simplify and standardize these analyses.

ICP Emission Spectrometry: Arsenic at 228 nm — Interferent or Analyte?

By Joachim Nölte, Bernhard Radziuk

This article compares several performance criteria such as full width at half maximum, background equivalent concentrations, limits of detection, purge requirements, and results for some substances for the "traditional" As lines at 188.979, 193.696, and 197.197 nm for the "new" line at 228.812 nm.

What New Methods to Measure Isotope Ratios Can Reveal About the Environment, Humans, and the Earth

By Spectroscopy Editors

Multiple-collector inductively coupled plasma–mass spectrometry (MC-ICP-MS) has some specific advantages over traditional ICP-MS instruments.

High-Resolution ICP-OES for the Determination of Trace Elements in a Rare Earth Element Matrix and in NdFeB Magnetic Materials

By Hassanali Savadkouei, Matthieu Chausseau, Zhaofen Li, Philippe Hunault, Alice Stankova

Rare earth elements (REEs) have become indispensable in many electronic, optical, magnetic, and catalytic applications because of their specific properties such as magnetism and phosphorescence, as well as their ability to both donate and accept electrons.

Improving ICP-MS Analysis of Samples Containing High Levels of Total Dissolved Solids

By Wim Proper, Ed McCurdy

A novel approach to handling samples with very high and variable levels of sample matrix is to use aerosol dilution, whereby the amount of sample aerosol that reaches the plasma is reduced by dilution with an additional argon gas stream.

Mass Spectrometry

GC–MS Analysis of an Herbal Medicinal Remedy to Identify Potential Toxic Compounds

By Irene W. Kimaru, Hang P. Nguyen

In most countries, herbal medicinal products (HMPs) are introduced into the market without proper scientific evaluation or enforced safety and toxicological studies.

Unraveling the Links Between Diet and Human Health Using LC–MS-MS

By Spectroscopy Editors

We recently spoke to Gary Duncan and Wendy Russell of the Rowett Institute of Nutrition & Health in Aberdeen, Scotland, about the significance of phytochemical bioavailability to human health and the important role of liquid chromatography linked to tandem mass spectrometry (LC–MS-MS) in their research.

Large-Scale Targeted Protein Quantification Using Wide Selected-Ion Monitoring Data-Independent Acquisition

By Vlad Zabrouskov, Sonia Ting, Reiko Kiyonami, Andreas F.R. Hühmer, Jarrett Egertson, Michael MacCoss, Michael Senko

This article describes the development of a new data-independent acquisition (DIA) workflow for protein quantification that uses a mass spectrometer that combines three types of mass analyzers to achieve lower limits of detection (LOD), higher sensitivity, more accurate quantitative results, wider dynamic range, and better reproducibility than existing high-resolution accurate-mass (HRAM) tandem mass spectrometry (MS-MS) DIA workflows.

Application of Ambient Sampling Portable Mass Spectrometry Toward On-Site Screening of Clandestine Drug Operations

By Christopher C. Mulligan, Seth E. Hall

Worldwide trends in illicit drug use and production have shifted toward an increase in synthetic analogues and the emergence of new variations in their manufacture.

Simultaneous Determination of Methylxanthines and Cotinine in Human Plasma by Solid-Phase Extraction Followed by LC–MS-MS

By Bodil Hammer Bech, Rossana Bossi

A multiresidue method has been developed and validated for the analysis of methylxanthines (caffeine and its metabolites) and cotinine in human plasma.