Special Issues-11-02-2005

November 02, 2005

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..

November 02, 2005

Plutonium 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.

November 02, 2005

Acquisition 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.

November 02, 2005

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.

November 02, 2005

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.

November 02, 2005

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..