title: Evaluation of extraction/digestion techniques used to determine lead isotopic composition in forest soils.
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.
authors.affiliation: Department of Agrochemistry and Plant Nutrition, Czech University of Agriculture in Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic. komarek@af.czu.cz
authors.forename: Michael
authors.initials: M
authors.lastname: Komárek
authors.forename: Vladislav
authors.initials: V
authors.lastname: Chrastný
authors.forename: Vojtech
authors.initials: V
authors.lastname: Ettler
authors.forename: Pavel
authors.initials: P
authors.lastname: Tlustos
mesh_terms: D005591:Chemical Fractionation / Q000379:methods; D004492:Edetic Acid; D007202:Indicators and Reagents; D007554:Isotopes / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D008722:Methods; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D014197:Trees
chemical_list: D007202:Indicators and Reagents; D007554:Isotopes; D012987:Soil; D012989:Soil Pollutants; D007854:Lead; D004492:Edetic Acid