Mass Spectrometry

Sample 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.

The 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.

As 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..

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.

Accurate and precise time and date stamps are critical to ensuring integrity of the data and results generated by each computerized system used in any spectroscopy laboratory.

This 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.

New 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.

Part III of this four-part series continues the discussion of mass calibration.

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.

The authors describe an in-situ cleaning verification technique that promises to be faster and more efficient than traditional methods, which use swab sampling followed by HPLC analysis. The technique is based upon FT-IR spectroscopy in the middle-infrared (mid-IR) range using reflection at a grazing angle.

A 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.

In this X-ray tutorial, the authors attempt to answer the frequently asked question, "How deep do the X-rays penetrate my sample?"

The 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.

Previous methods for linearity testing discussed in this series contain certain shortcomings. In this installment, the authors describe a method they believe is superior to others.

Innov-X Corporate Profile (PDF)

Spectroscopy previews products and sessions for attendees to see and participate in at the 54th Annual Denver X-Ray Conference, to be held August 1–5 in Colorado Springs, CO.

In this study X-ray absorption was used to determine the effect of pH on the coordination of lead to humin and sphagnum peat moss. The authors determined the oxidation state and the coordination of lead to both humin and sphagnum peat moss using X-ray near edge structure and extended X-ray absorption fine structure spectroscopy. In addition, inductively coupled plasma optical emission spectroscopy was used to determine the amount of lead bound to the humin and sphagnum peat moss in the pH range 2–6.

Laser ablation ICP-MS enables identification and comparison of physical crime-scene evidence. Discriminating elemental and isotopic differences of solid samples directly at the parts-per-billion level provides forensic scientists with a powerful analytical tool.

Confocal Raman microscopy can be useful when applied to all samples that are heterogeneous on the micrometer to millimeter scale and that generally can be investigated by Raman spectroscopy. This article presents examples of confocal Raman microscopy from various fields of application including pharmaceutical analysis and stress measurements in semiconductors.

A new system for multitechnique spectral searching is described that utilizes analysis of several hit lists resulting from spectral similarity searches performed simultaneously in reference databases for multiple complementary analytical techniques. This paper demonstrates the benefits of this multitechnique approach using the complementary techniques of IR and Raman spectroscopy.

Compounds of magnesium and calcium are common components of pharmaceutical formulations. Spectroscopic imaging can provide a complete understanding of a formulation. This paper compares two spectral imaging techniques — energy dispersive X-ray fluorescence (EDXRF) microscopy and Raman microscopy.

The authors present a novel technique for obtaining very high stability and reproducibility of a Raman spectrum, using grating corrected laser stabilization. An externally stabilized laser with a grating spectrometer provides exceptional quantum efficiency in the entire dynamic range. These components then are used to build a library of pharmaceutical raw materials and tested on samples of unknown material.

Due to its high information, vibrational content, the Raman spectrum provides important and specific molecular information. In this article, Raman microanalysis and instrumentation is discussed with specific application to the forensic science laboratory, where evidence integrity is of the utmost importance.

The acquisition of Raman spectra can be eased greatly through the use of surface-enhanced Raman spectroscopy (SERS). In this article, the authors discuss a new substrate technology that delivers reliable and consistent surface enhancement.

Raman spectroscopy has been employed to detect Bacillus cereus spores, an anthrax surrogate, collected from a letter as it passed through a mail sorting system. Raman spectroscopy also has the ability to identify many common substances used as hoaxes. A three-step method also is described for the detection of dipicolinic acid extracted from surface spores by SERS.