October 2006. The authors investigate the optical properties and thickness of natural SiO2 thin films grown on silicon substrates simultaneously with a VASE system by choosing different angles of incidence and wavelength ranges.
Mercury is a toxic, persistent pollutant found in many native ores rich in copper, silver and gold. As such ores are processed mercury can be released to the environment.
October 2006. The authors investigate the optical properties and thickness of natural SiO2 thin films grown on silicon substrates simultaneously with a VASE system by choosing different angles of incidence and wavelength ranges.
The authors discuss progress in near-field IR microspectroscopy using a photothermal probe and show how it can be applied to the spectroscopic characterization of real-world samples.
The authors discuss progress in near-field IR microspectroscopy using a photothermal probe and show how it can be applied to the spectroscopic characterization of real-world samples.
Spectroscopy previews the 36th FACSS, to be held October 18–22, 2009, in Louisville, Kentucky.
In 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.
The potential for signal drift, matrix suppression, and spectral interference, in addition to demanding sample preparation, can make geological matrices some of the most difficult to analyze by conventional inductively coupled plasma-mass spectrometry.
Spectroscopy columnist Ken Busch once again brings readers his comprehensive list of common acronyms used in the field of mass spectrometry.
A new approach to enhancing the performance of formula identification of true unknowns beyond high mass and spectral accuracy was evaluated. Three heuristic rules on upper limits and ratios of elements were tested for their effectiveness in filtering out false positive formulas with both high- and low-resolution mass spectrometry data. The rule on elements' upper limits was found to be the most effective one in eliminating incorrect formulas.
Elemental 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..
There is often insufficient prevention to ensure safe swimming environments. Recreation water illness (RWI), most commonly in the form of digestional track illness as well as skin, ear, and respiratory infections, are often caused by water contamination from human waste. Stercobilin is a very stable and suitable chemical biomarker of human waste that has the potential to be used for waste monitoring in public swimming facilities. Using solid phase extraction (SPE) techniques paired with high-resolution mass spectrometry (HRMS), we have developed a robust method used for swimming pool water monitoring to create safer swimming environments.
Off-line 2-D LC–MS-MS represents a powerful alternative to on-line methodologies for protein identification from complex proteomes, improving the chromatographic resolution of digest peptide mixtures, even for low-abundance proteins. Here, the authors provide a detailed comparison of the two techniques.
Here, the authors discuss a multielement method for the simultaneous determination of inorganic As, Cr, and Se species in potable waters using a HPLC system coupled to a dynamic reaction cell indusctively coupled plasma mass spectrometer.
A detailed look at the most critical component of an ICP-MS instrument: the interface cones
The potential for signal drift, matrix suppression, and spectral interference, in addition to demanding sample preparation, can make geological matrices some of the most difficult to analyze by conventional inductively coupled plasma-mass spectrometry.
Elemental analysis of food substances presents a challenge because of the wide variety of food types and range of concentrations that need to be analyzed. This article discusses the analysis of a variety of food matrices with a single digestion procedure and instrumental method.
The RoHS/WEEE directive requires the electronics industry to certify that products comply with maximum concentration amounts of particular elements and compounds (Cr VI, Pb, Cd, Hg, Br PBB/PBDE) by July 2006. Instrumentation must be developed to perform the certification.
High-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.
High-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.
NIR-CI adds a completely new dimension to conventional spectroscopy.
This year's survey of salaries and job attitudes reveals that the market seems stable, but many spectroscopists are feeling the pressure of the economy at work.
The authors review the operating principles of a silicon Raman laser and show that by introducing a longitudinal variation of the waveguide width in the cavity, the lasing efficiency can be increased significantly.
The authors discuss g-hydroxybutyrate (GHB), a drug of abuse that is not detected in the drug-detection mode or positive polarity of commercial ion mobility spectrometers, but can be detected by ion mobility spectrometry (IMS) instruments in negative mode.
Off-line 2-D LC–MS-MS represents a powerful alternative to on-line methodologies for protein identification from complex proteomes, improving the chromatographic resolution of digest peptide mixtures, even for low-abundance proteins. Here, the authors provide a detailed comparison of the two techniques.
The authors discuss several sample types encountered in their laboratory for which Raman spectroscopy is the only reliable method of analysis. The technique is shown to be a routine and cost-effective tool for the industrial laboratory.
Here, the authors discuss a multielement method for the simultaneous determination of inorganic As, Cr, and Se species in potable waters using a HPLC system coupled to a dynamic reaction cell indusctively coupled plasma mass spectrometer.
September 2006. The authors rapidly acquire complete vibrational spectra in the fingerprint region using a single femtosecond laser for broadband coherent anti-Stokes Raman scattering (CARS) microscopy to image spatially variant compositions of condensed-phase samples.