Evaluation of extraction/digestion techniques used to determine lead isotopic composition in forest soils

Anal Bioanal Chem. 2006 Jul;385(6):1109-15. doi: 10.1007/s00216-006-0543-x. Epub 2006 Jun 21.

Abstract

Lead isotopic studies in soils provide an efficient tool for tracing the sources of lead pollution. Five different extraction/digestion techniques (0.05 M EDTA, 0.5 M HNO(3), 2 M HNO3, aqua regia, total digestion) were used for lead isotopic composition (206Pb/207Pb) determination in three forest soil profiles with different kinds of prevailing Pb contamination (unpolluted area, smelting area and vicinity of a motorway). The results obtained showed that all extraction/digestion methods used for the determination of 206Pb/207Pb ratios in surface horizons containing high organic matter contents gave statistically identical values (according to the Tukey test). In mineral soil horizons, differences between the individual extraction/digestion methods could be observed (the lowest 206Pb/207Pb ratios were obtained from EDTA extracts, corresponding to weakly bound anthropogenic lead, and the highest 206Pb/207Pb ratios were obtained from total digestion). The combination of total digestion and EDTA extraction (labile lead fraction) seems to be the optimal combination for 206Pb/207Pb ratio determination and optimal result interpretation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemical Fractionation / methods
  • Edetic Acid
  • Indicators and Reagents
  • Isotopes / analysis*
  • Lead / analysis*
  • Methods
  • Soil / analysis*
  • Soil Pollutants / analysis*
  • Trees

Substances

  • Indicators and Reagents
  • Isotopes
  • Soil
  • Soil Pollutants
  • Lead
  • Edetic Acid