Spectroscopy

March 2010, Volume 25, Number 3

COLUMNS

MOLECULAR SPECTROSCOPY WORKBENCH
Depth Resolution of the Raman Microscope: Optical Limitations and Sample Characteristics
Fran Adar looks at the determination of the depth resolution of a Raman microscope.
Fran Adar
MASS SPECTROMETRY FORUM
A Random Walk Through the Web of Mass Spectrometry
Ken Busch discusses the revolution in data storage and its impact on the MS community.
Kenneth L. Busch
ATOMIC PERSPECTIVES
Electron Transitions in Optical Emission and X-Ray Fluorescence Spectrometry
The authors present an X-ray energy level diagram for magnesium showing the major electron transitions, then compare it to an OES diagram for the same element.
Volker Thomsen and Carlos Augusto Coutinho

2010 Salary Survey
Megan Evans presents the results of Spectroscopy’s annual industry survey.
Megan Evans
Spectroscopy Bounces Back
SDi president Lawrence Schmid brings Spectroscopy readers his annual analysis of the spectroscopy market.
Lawrence S. Schmid

February 2010, Volume 25, Number 2

MOLECULAR SPECTROSCOPY WORKBENCH
Analysis of Lignin and Cellulose in Biological Energy Sources by Raman Microscopy
Cellulosic feedstocks from biological harvests or industrial–urban waste have been proposed as sources for the production of energy in the form of fermentation-produced ethanol biofuel. Because Raman measurements are nondestructive, they can provide information on the relative concentrations of the feedstock components.
Fran Adar
CHEMOMETRICS IN SPECTROSCOPY
Statistics and Chemometrics for Clinical Data Reporting, Part III: Using Excel for Data Plotting
This installment of “Chemometrics in Spectroscopy” illustrates the various graphical ways used to observe and interpret comparative clinical quantitative measurement methods.
Jermome Workman and Howard Mark

Assessing Accuracy
In a previous article, we discussed the steps in the chemical analysis process (sample taking, sample preparation, analysis, and results) and promised a follow-up on the question of the accuracy of the results. This article examines systematic error and quantitative analysis.
Volker Thomsen
Differentiation Between Origins of Extra Virgin Olive Oils by GC–C-IRMS Using Principal Component Analysis, Linear Discriminant Analysis, and Hierarchical Cluster Analysis
The authors classify extra virgin olive oils from Portugal and Turkey using GC–C-IRMS to evaluate the isotope ratios of the fatty acid methyl esters (FAMEs) extracted from the oils.
Andreas Baum, Yao Lu, Zeland Muccio, Glen P. Jackson, and Peter B. Harrington
CHCA or DHB? Systematic Comparison of the Two Most Commonly Used Matrices for Peptide Mass Fingerprint Analysis with MALDI-MS
The authors present a comprehensive study of MALDI spotting, based upon the most commonly used dried droplet method, for various peptides of different molecular weight and concentration.
Cunjie Zhang, Haixia Zhang, David W. Litchfield, and Ken K.-C. Yeung

January 2010, Volume 25, Number 1

THE BASELINE
Group Theory and Symmetry, Part II: Groups
In the previous installment of this column, David Ball introduced the five types of symmetry elements that are important in physical science. Here, he discusses why it’s called “group” theory in the first place.
David W. Ball
MASS SPECTROMETRY FORUM
Mass Spectral Libraries: The Next Generation
Fundamentally new manipulations of data contained in mass spectral databases and libraries are envisioned for the next generation of mass spectral libraries, including developments both in very specialized collections as well as broader collections accessed through a web- and cloud-based network. Here, Ken Busch exmaines these
developments. Kenneth L. Busch
LASER AND OPTICS INTERFACE
How Optical Advances Helped Deliver the Promise of Miniature Spectrometers
Performance gaps in the industry’s earliest miniature spectrometers today have been mitigated by the ongoing improvement of gratings, coatings, mirrors, and other spectrometer bench optical components.
Robert Morris

Speciation of Mercury in Crude Oil Using Speciated Isotope Dilution Mass Spectrometry
ICP-MS and IDMS for crude oil analysis are explored.
G.M. Mizanur Rahman, Timothy M. Fahrenholz, H.M. Skip Kingston, Matt Pamuku, J. David Hwang, and Lyman A. Young
Spectrometers for Elemental Spectrochemical Analysis, Part I: The Basic Spectrometer
An overview of the instrumentation used in elemental spectrochemical analysis.
Volker Thomsen