August 15th 2024
A recent study examined the role of high-resolution mass spectrometry imaging in assessing environmental contaminants.
Process Monitoring: In-line, At-line, or Slip-stream?
February 1st 2006As process analytical technology (PAT) moves out of the laboratory and into the plant and to the process stream itself, the question arises, "What is the best way to collect data from stream samples?" The author shows that this depends upon both the nature of the stream and the components to be measured.
ICP-MS Speciation Analysis: Three Roles of Selenium
February 1st 2006The element selenium plays three distinct roles in biological processes, functioning in turn as a toxicant, a chemopreventive agent, and a heavy metal antagonist. This article discusses current research associated with each role, and how ICP-MS can be employed to better understand and utilize selenium's properties.
End of the Spectrum: The Changing Trend in U.S. Research Funding
February 1st 2006Most of the 2.2 billion dollars increase in the 2006 federal research and development budget will go toward defense weapons development and human space exploration technologies, according to the American Association for the Advancement of Science.
Mars Express Finds Evidence of Liquid Water on Mars
January 1st 2006Since the discovery of gullies on Mars in 2000, NASA has endeavored to re-image areas known to have them. Now for the first time, using before and after images taken of the same region on Mars, a dune gully flow is shown to have happened very recently.
Tech Note — The Difference Between VFA and FT-IR Spectra
December 1st 2005The basic characteristics of variable filter array (VFA) spectrometers, both near- and mid-infrared, make them well suited for routine infrared analysis applications outside and inside the laboratory. The performance of this spectrometer is discussed here.
Tutorial — Mass Analyzers: An Overview of Several Designs and Their Applications, Part II
December 1st 2005The second installment of this two-part series illustrates further technical principles and applications of the most common mass analyzers used in bioanalytical laboratories today, as well as novel techniques and mass analyzer designs. Examples are based upon the authors' research in small molecule applications.
Rapid, Cost-Effective, and Routine Biomedical Analysis Using ICP-MS
November 2nd 2005Elemental analysis in biological samples generally is achieved using flame atomic absorption spectrometry (AAS) and graphite furnace AAS (GFAAS). Flame AAS is fast, easy-to-use, and economical, but insufficiently sensitive for assays such as Se in serum and Pb/Cd in whole blood. These measurements require use of the more sensitive GFAAS. Inductively coupled plasma-mass spectrometry (ICP-MS), despite its low detection limit capabilities and wide elemental range, has had relatively little impact to date on biomedical analysis because of the popularly held conception that it is complex to use and expensive. In recent years, the instrumentation has been simplified and purchase, running, and maintenance costs have fallen. As a result, clinicians are becoming more interested in ICP-MS, although the perception that it is still much more expensive than GFAAS remains. This article provides a comparison of the costs of ICP-MS and GFAAS for biomedical sample analysis and illustrates the performance of ICP-MS for..
ICP-MS Studies of Plutonium in the Environment
November 2nd 2005Plutonium is distributed globally in the Earth's surface environment as a result of atmospheric weapons tests, nuclear accidents, and nuclear fuel reprocessing. Mass spectrometry (MS), in particular, sector field ICP-MS, now is used widely to determine Pu activities and isotope ratios; 240Pu/239 is very useful in determining Pu origin. Determination of Pu by ICP-MS involves dissolution, column separation, and the MS determination; detection limits are 0.1–10 fg for each isotope. Applications of the determination of sector field ICP-MS to studies of environmental Pu include discerning sources of contamination near the Chernobyl reactor, and chronology of recent aquatic sediments.
A Dedicated Spectra Database for Multiline Selection in ICP-AES
November 2nd 2005Acquisition and interpretation of a spectra database for ICP-AES analysis are described. The aim is the selection of nanometer-wide spectral windows containing several elements and several lines per element, so as to perform multiline analysis. An automatic line assignment procedure has been used. Information such as wavelength, sensitivity, line width, limit of detection, and level of detector saturation are stored. Filtering procedures are used for line selection, taking into account concentrations and possible spectral interferences.
Sample Introduction for ICP-MS and ICP-OES
November 2nd 2005Sample introduction can be a significant source of random and systematic error in the measurement of samples by inductively coupled plasma optical emission spectroscopy (ICP-OES) and ICP mass spectrometry (ICP-MS) systems.The considerations made in selecting a liquid introduction system include dissolved solids content, suspended solids presence, presence of hydrofluoric acid or caustic, detection limit requirements, precision requirements, sample load requirements, sample size limitations, and operating budget. The analyst is left with the task of choosing the best introduction components.This article discusses the key components of a typical liquid sample introduction system for inductively coupled plasma spectroscopy, and offers troubleshooting tips for problems commonly encountered by practitioners.
Analysis of Soil and Sewage Sludge by ICP-OES
November 2nd 2005The analysis of soil and sewage sludge by ICP-OES using a novel CCD optic concept, which allows for the transfer of methods between different instruments, is described. Sample preparation was performed according to EN 13346:2000. The accuracy was investigated using the standard reference materials, BCR-141R and NIST 2781. It could be demonstrated that the requirements in terms of sensitivity, precision, and accuracy to perform the analysis of soil and sewage sludge can be met. The article includes line selection, detection limits, and studies on accuracy.
The Determination of Nitrogen and Other Essential Elements in Fertilizers by ICP-OES
November 2nd 2005As the demand for accurate soil analysis increases, agriculturalists will need faster, less expensive analytical methods to determine the type and amount of fertilizer required for optimum crop growth. Today, inductively coupled plasma–optical emission spectroscopy (ICP-OES) is the most commonly employed technique for the determination of nutrient elements in fertilizers, while combustion analysis is used for nitrogen. Until recently, ICP-OES could not achieve the accuracy and precision necessary to measure nitrogen due to the elevated background effects caused by atmospheric nitrogen, as well as the inherent stability limitations associated with older instrument designs. This paper describes a new ICP-OES configuration and sample introduction system designed to greatly reduce nitrogen backgrounds and thereby facilitate nitrogen determinations by ICP-OES. Furthermore, the nitrogen determinations are carried out concurrently with the other nutrient elements previously reported by ICP-OES without..
Savitzky–Golay Smoothing and Differentiation Filter of Even Length: A Gram Polynomial Approach
November 1st 2005In various fields such as signal processing, imaging processing, analytical chemistry, and spectroscopic analysis, smoothing and differentiation is important and necessary. With a matrix approach, the Savitzky–Golay smoothing and differentiation filter was extended recently to even length. In this article, a more general approach is proposed for convenient computation.
Tutorial — Mass Analyzers: An Overview of Several Designs and Their Applications, Part I
November 1st 2005This tutorial illustrates the technical principles and typical applications of the most common mass analyzers used in bioanalytical laboratories today, as well as novel techniques and mass analyzer designs. Examples are based upon the authors' research in small molecule applications.
Continuous Wave Optical Parametric Oscillators Break New Spectral Ground
November 1st 2005New mid-infrared spectroscopic sources, based upon advances in fiber lasers and in nonlinear frequency conversion, are now enabling high-resolution laser spectroscopy in the 2–4 μm wavelength region and beyond. With this in mind, the authors discuss continuous wave (CW) optical parametric oscillators (OPOs) in particular.
New Capabilities of High-Resolution Ultrasonic Spectroscopy: Titration Analysis
October 1st 2005High-resolution ultrasonic spectroscopy titration analysis is a powerful new tool in research and analytical laboratory work for quantitative measurements of different processes and compounds. Here, the authors explore its potential.
Spectroscopy and the Search for Ancient Life on Mars, Continued
September 1st 2005A report published earlier this year (1) discussed a UV–vis-NIR instrument designed for use on NASA Mars rover missions. This article follows up with coverage of the Planetary Fourier Spectrometer on the European Space Agency's Mars Express orbiter mission.
Using SR-IMS to Study the Fate and Transport of Organic Contaminants in Plants
September 1st 2005The fate and transport of organic contaminants and their impact upon plant development has been an important topic in environmental science. Here the authors report the use of synchrotron radiation Fourier-transform infrared microspectroscopy (SR-IMS) as a direct method for monitoring the fate and effects of 2,6-dinitrotoluene (2,6-DNT) in maize (Zea mays L.) root tissue.