Kenneth Pye
Associates
Ltd.
Scientific Research,
Consultancy and Investigations
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Chemical Analysis
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Major and Trace Element Analysis A wide range of solid samples can be digested and analysed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP mass spectrometry (ICP-MS) to quantify the abundance of major, minor and trace elements. Concentrations of up to 50 elements can be determined in small samples (>0.25 g). Where sample size is not limited, the composition can also be determined by x-ray fluorescence (XRF) analysis. Data can be processed to meet specific requirements using in-house proprietary software. The data obtained can be compared with reference database information obtained from a wide range of environments and geographical coverage.Examples using ICP data
Examples using XRF data
Stable Isotope Analysis The 'light' elements hydrogen, carbon, nitrogen, oxygen and sulphur possess two or more stable isotopes which do not undergo radioactive decay. The isotopic ratios of these elements have been demonstrated to be useful indicators of many geological and biological processes. Ratios are determined either by continuous helium flow isotope ratio mass spectrometry (CF-IRMS) or combustion-gas chromatography isotope ratio mass spectrometry (C-GC-IRMS).
Bivariate plots of δ13C against δ15N
for: (left) the <150 mm, and (right) the >150
mm fractions of soil samples taken from one metre square
pH, Eh, Electrical Conductivity and Anion Analysis Determination of pH, Eh and electrical conductivity (or total dissolved solids) can provide a useful indication of temporal and spatial variations in environmental conditions. Analyses can be performed in the field or laboratory using ion-selective electrodes. Anion determination by ion chromatography can also provide a rapid method of detecting variations in water and sediment character.
Related Publications and Reports Pye,
K., Blott, S.J.,
Croft, D.J. and
Witton, S.J. (2007).
Discrimination between sediment and soil samples for forensic purposes using
elemental data: An investigation of particle size effects.
Forensic Science International 167, 30-42. Pye,
K., Blott, S.J.,
Croft, D.J. and Carter, J.F. (2006). Forensic comparison of soil samples:
assessment of small-scale spatial variability in elemental composition, carbon
and nitrogen isotope ratios, colour, and particle size distribution.
Forensic Science International 163, 59-80. Pye,
K., Blott, S.J.
and Wray, D.S. (2006). Elemental analysis of soil samples for forensic
purposes by Inductively Coupled Plasma Spectrometry – precision considerations.
Forensic Science International 160, 178-192. Saye, S.E., Pye,
K. and Clemmensen, L.B. (2006) Development of a cliff-top dune indicated by particle size and
geochemical characteristics: Rubjerg Knude, Denmark. Sedimentology 53,
1-21. Saye, S.E. and Pye,
K.
(2006). Variations in chemical composition and particle size of dune
sediments along the west coast of Jutland, Denmark. Sedimentary Geology
183, 217-242. Pye, K.
and Blott, S.J. (2004).
Comparison of soils and sediments using major and trace element data.
In:
Pye, K. and
Croft, D. (Eds.) Forensic Geoscience - Principles, Techniques and
Applications.
Geological Society Special Publication No. 232, Geological Society
Publishing House, Bath, pp. 183-196. Saye, S.E.
and Pye, K. (2004) Development of a coastal dune sediment database for England and Wales:
forensic applications. In:
Pye, K.
and
Croft, D. (Eds.) Forensic Geoscience - Principles, Techniques and
Applications.
Geological Society Special Publication No. 232, Geological Society
Publishing House, Bath, pp. 75-96. Croft, D.J. and Pye, K.
(2004) Stable carbon and nitrogen isotope variations in soils: forensic
applications. In:
Pye, K.
and
Croft, D. (Eds.) Forensic Geoscience - Principles, Techniques and
Applications.
Geological Society Special Publication No. 232, Geological Society
Publishing House, Bath, pp. 257-267. Croft, D.J. and Pye,
K. (2003) The
potential use of continuous-flow isotope-ratio mass spectrometry as a tool in
forensic soil analysis: a preliminary report.
Rapid Communications in Mass Spectrometry 17, 2581-2584. |
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