Geological samples, analysis

The quantitative imaging capability of the NMP is one of the major strengtiis of the teclmique. The advanced state of the databases available for PIXE [21, 22 and 23] allows also for the analysis of layered samples as, for example, in studying non-destmctively the elemental composition of fluid inclusions in geological samples. 

Thermal neutron activation analysis has been used for archeological samples, such as amber, coins, ceramics, and glass biological samples and forensic samples (see Forensic chemistry) as weU as human tissues, including bile, blood, bone, teeth, and urine laboratory animals geological samples, such as meteorites and ores and a variety of industrial products (166). 

The development of G-i and W-i (Ahrens 1951 Fairbairn et al.1951 Stevens et al. i960) was the response to this demand with respect to dc arc emission spectrogra-phy. As similar samples are used routinely in calibration for XRF and INAA analyses, many geological samples have been developed as reference materials since that time to support geoanalysis (Potts et al.1992). Just as the change from classical to instmmental methods of analysis changed the nature of demands for reference... 

Comment Wismuterz II (AGV-i) and Blei JG-ia were used as certified geological samples, but no CRM used for the (more difficult) water analysis... 

Totland M, Jarvis 1, Jarvis KE (1992) An assessment of dissolution techniques for the analysis of geological samples by plasma spectrometry. Chem Geol 95 35-62... 

Nimmerfall G, Schron W (2001) Direct solid sample analysis of geological samples with SS-GF-AAS and use of 3D calibration. Fresenius J Anal Chem 370 760... 

The technique is used predominantly for the isolation of a single chemical species prior to a determination and to a lesser extent as a method of concentrating trace quantities. The most widespread application is in the determination of metals as minor and trace constituents in a variety of inorganic and organic materials, e g. the selective extraction and spectrometric determination of metals as coloured complexes in the analysis of metallurgical and geological samples as well as for petroleum products, foodstuffs, plant and animal tissue and body fluids. 

China Geological Survey. 2005 Technical Requirements of Sample Analysis in Ecological Geochemical Assessment (trial Implementation). DD2005-03 (in Chinese). 

Acknowledgements We would like to give our thanks to the analytical technicians for their hard work on the sample analysis and to the geochemical technicians at the Geological Survey of Zhejiang province for their assistance in the field work. 

Once geological samples are dissolved, a mixed Ca- Ca tracer is added to the sample ( Ca/ Ca 1). The isotopic abundances in the mixed sample-tracer solution are illustrated in Figure 1. When the mixed solution has roughly equal amounts of the isotopes Ca, Ca, and Ca, then a near-optimal situation is achieved with regard to the corrections for the presence of the tracer (cf Johnson and Beard 1999 for a detailed analysis of spike-sample ratios). The... 

Wilson and McGregor [2S] concluded that it is appropriate to use robotics for grinding materials for geological samples. Studies deahng with cross contamination revealed that even samples containing levels of Ph, Zn or Cr above 1% did not pose a problem, provided that 2S g of sand is used to clean the system prior to the next sample analysis. 

Nielson, K.K., Sanders, R.W. 1983. Multielement analysis of unweighed biological and geological samples using backscatter and fundamental parameters. Advances in X-Ray Analysis 1983, 26, 385-390. 

Element Analysis of Geological Samples by ICP-MS at the Geoscience Laboratories Revised Capabilities Due to Improvements to Instrumentation. In Summary of Field Work and Other Activities 2004. Ontario Geological Survey Open File Report 6145, 54-1 to 54-20. 

In this research, the purpose of the cluster analysis Is to obtain groupings of samples with compositions similar to specific minerals or with only a subset of all the minerals In the bulk sample. This Is necessary In most geological samples In order to... 

To convert geologic samples to a suitable form for analysis, many different chemical preparation techniques must be used. These diverse techniques all have one general feature in common any preparation procedure providing a yield of less than 100% may produce a reaction product that is isotopically different from the original specimen because the different isotopic species have different reaction rates. 

Flame atomic absorption spectrometry can be used to determine trace levels of analyte in a wide range of sample types, with the proviso that the sample is first brought into solution. The methods described in Section 1.6 are all applicable to FAAS. Chemical interferences and ionization suppression cause the greatest problems, and steps must be taken to reduce these (e.g. the analysis of sea-water, refractory geological samples or metals). The analysis of oils and organic solvents is relatively easy since these samples actually provide fuel for the flame however, build-up of carbon in the burner slot must be avoided. Most biological samples can be analysed with ease provided that an appropriate digestion method is used which avoids analyte losses. 

The identification of compounds using powder diffraction is useful for qualitative analysis, such as mixtures of small crystals in geological samples. It also gives a rough check of the purity of a sample—but note that powder diffraction does not detect amorphous products or impurities of less than about 5%. 

For measurements of isotope ratios or isotope abundances, any of the mass spectrometers discussed in the previous chapters, such as SSMS, LIMS, GDMS56 and LA-ICP-MS,6 are of benefit for the direct isotope analysis of solid samples. SSMS and LIMS are rarely applied in isotope analysis due to their relatively low precision. Several applications of the isotope dilution technique as a calibration strategy in SSMS, mostly on geological samples, are known.57-59 GDMS has been mostly applied in multi-element trace analysis and depth profiling and plays only a minor role... 

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