Determination of lead isotope ratios in environmental matrices by quadrupole ICP-MS working at low sample consumption rates

Abstract

Measurement of lead isotope ratios in environmental matrices using inductively coupled plasma-dynamic reaction cell-mass spectrometry at low sample consumption rates was investigated. Two micro-sample introduction systems were evaluated, namely the PFA micronebuliser associated with a low-volume spray chamber, working at 150 mL min?1 and the total-consumption sample introduction system TISIS, operating at 20 mL min?1. In both cases, the dynamic reaction cell pressurised with ammonia was applied to improve the precision by collisional damping. Under optimal operating conditions, 208Pb/207Pb and 206Pb/207Pb ratios were accurately determined with an internal precision of 0.12–0.13% and 0.17–0.18% (%RSD, n ¼ 10, c ¼ 10 mgL?1; t ¼ 10 s). The sample consumption for the assessed sample introduction systems was less than 1.5 mL and 200 mL, allowing the precise analysis of limited-size samples and pre- concentrates. The developed method was characterised in terms of the analytical working range, in-cell interference, and uncertainty estimation. The applicability of the analytical method was demonstrated by the analysis of the lichen reference material CRM 482, as well as those of several environmental samples collected from polar regions, including atmospheric particulate, snow, marine suspended particulate matter and sediment. In particular, by combining a simple pre-concentration procedure with the application of TISIS, it was possible to perform the lead isotope analysis of Antarctic snow samples at the pg g?1 concentration level

2014 atomic spectrometry update – a review of advances in environmental analysis

“…This procedure provided results traceable to the SI and further measurements at dened temperatures are anticipated once this system has been thermostated. Use of a total consumption nebuliser 62 operating at a ow rate of 20 mL min À1 allowed 208 Pb/ 207 Pb and 206 Pb/ 207 Pb ratios to be determined accurately by DRC ICP-MS with an internal precision of 0.12-0.13% and 0.17-0.18% (n ¼ 10, 10 s integration time and a test solution of 10 mg L À1 Pb) respectively. Collisional dampening in the DRC cell which was pressurised with NH 3 improved the precision.…”

Direct lead isotopic analysis of bioethanol by means of multi-collector ICP-mass spectrometry with a total consumption sample introduction system

“…The combination of an hTISIS and MC-ICP-MS has been previously used for carrying out studies in aqueous sample matrices, aiming at improving the sensitivity and/or at reducing the volume of sample required for the analysis. [31][32][33][34][35] However, its application to direct isotopic analysis of organic samples has not been investigated yet.…”

Lead isotopic analysis of Antarctic snow using multi-collector ICP-mass spectrometry

“…In this work, snow samples were rst submitted to analyte preconcentration, based on sample volume reduction by freezedrying. 17 The solutions thus obtained were introduced into an MC-ICP-MS instrument for Pb isotopic analysis using a TISIS. This analytical protocol was optimised, characterised in terms of precision and accuracy at ultra-trace concentration level, and, nally, applied to the analysis of recent snow collected from Antarctica during two year-round expeditions.…”