An isotopic perspective on mass bias and matrix effects in multi-collector inductively-coupled-plasma mass spectrometry
- 20 February 2012
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of Analytical Atomic Spectrometry
- Vol. 27 (4), 653-662
- https://doi.org/10.1039/c2ja10382f
Abstract
Lead and Tl isotope intensities and ratios were measured in radial and axial plasma profiles using multi-collector inductively-coupled-plasma mass spectrometry (MC-ICP-MS). Signal profiles for 204Pb, 206Pb, 207Pb and 208Pb display mass dependent radial and axial distributions in the plasma. In radial profiles lighter isotopes exhibit greater dispersal from the plasma axis than heavier isotopes, in agreement with ICP-MS elemental observations. However, signal maxima (Imax) for heavier Pb isotopes occur closer to the load coil than Imax for lighter Pb isotopes, the reverse of ICP-MS elemental observations. These mass dependent distributions predict that the radial dispersion and axial Imax locations for 203Tl and 205Tl isotopes should occur interspersed with the values for simultaneously measured Pb isotopes. Instead however, their values are appropriate for masses greater that 208Pb, indicating that the observed profiles are not the product of a single stage mass dependent process and that other element properties also effect the distributions. Isotope ratio (and thus mass bias) variation with sampling depth reflects both the mass dependent separation of the numerator and denominator isotope Imax along the axis of the plasma and the distance along the axis of the plasma over which the isotope signals are distributed. Addition of matrix to the plasma significantly reduces the variability of these two characteristics suggesting that more accurate correction of instrumental mass bias and more accurate normalization of sample ratios to standard values could be achieved by addition of a common matrix to samples and standards.Keywords
This publication has 23 references indexed in Scilit:
- Effects of operating conditions and matrix on mass bias in MC-ICPMSJournal of Analytical Atomic Spectrometry, 2009
- Matrix effects on the multi-collector inductively coupled plasma mass spectrometric analysis of high-precision cadmium and zinc isotope ratiosAnalytica Chimica Acta, 2009
- Identification of a matrix effect in the MC-ICP-MS due to sample purification using ion exchange resin: An isotopic case study of molybdenumInternational Journal of Mass Spectrometry, 2008
- Determination of mass-dependent molybdenum isotopic variations by MC-ICP-MS: An evaluation of matrix effectsChemical Geology, 2006
- Sources of mass bias and isotope ratio variation in multi-collector ICP-MS: optimization of instrumental parameters based on experimental observationsJournal of Analytical Atomic Spectrometry, 2004
- Precise and accurate isotopic measurements using multiple-collector ICPMSGeochimica et Cosmochimica Acta, 2004
- Investigation of the mass discrimination of multiple collector ICP-MS using neodymium isotopes and the generalised power lawJournal of Analytical Atomic Spectrometry, 2003
- Multicollector ICP-MS analysis of Pb isotopes using a 207pb-204pb double spike demonstrates up to 400 ppm/amu systematic errors in Tl-normalizationChemical Geology, 2002
- Precise analysis of copper and zinc isotopic compositions by plasma-source mass spectrometryChemical Geology, 1999
- Determination of lead isotope ratios by inductively coupled plasma-mass spectrometry (ICP-MS)Spectrochimica Acta Part B: Atomic Spectroscopy, 1987