Isotope ratio analysis of lead in biological materials by inductively coupled plasma mass spectrometry

ICP-MS determination of lead isotope ratios in legal and counterfeit cigarette tobacco samples

A method for the determination of Pb isotope ratios (IR) in cigarette tobacco by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) has been developed and applied to tobacco samples from genuine and counterfeit cigarettes obtained in the USA. The IR ²⁰⁷Pb/²⁰⁶Pb, (208)Pb/²⁰⁶Pb, ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb were measured using a Q-ICP-MS instrument. Two certified reference materials, grown in the USA and Bulgaria, were also analysed for comparison with the tobacco samples, as were tobacco samples from cigarettes obtained in Pakistan and China. The precision of the results was sufficient to distinguish between the counterfeit and genuine USA cigarettes. All of the genuine cigarettes and both reference materials, grown in different regions, were statistically distinct based on the measured ratios. The counterfeit cigarettes were indistinguishable from the reference material grown in Bulgaria. The technique shows promise as a method for identifying counterfeit cigarettes, possibly determining the source region.

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors

Leg and foot bones of adult and juvenile red grouse (Lagopus lagopus scoticus) were collected from hunter-shot birds on two Scottish estates (Glendye and Invermark) and one Yorkshire estate in September, 2003. The lead content of bones was measured by atomic absorption spectrophotometry, and corresponding stable lead isotopes (Pb(204, 206, 207, 208)) by inductively coupled plasma mass spectrometry. At the Glendye (N=111) and Invermark (N=85) estates, relatively few birds (5.4% and 3.5%, respectively) had highly elevated bone lead concentrations (>20 microg/g dry weight). In bones of these highly exposed birds, a combination of Pb(206):Pb(207) and Pb(208):Pb(207)ratios was consistent with ingestion of lead gunshot available in Europe. By contrast, Yorkshire grouse experienced a high incidence (65.8%) of bone lead >20 microg/g. The Pb(206):Pb(207) and Pb(208):Pb(207)ratios in bones of these highly exposed birds were consistent with a combined exposure to ingested lead gunshot and lead from galena mining in the region. Lead isotope ratios also indicated that lead from UK gasoline combustion and fallout from atmospheric particles was not a likely source of elevated lead in bones of either Scottish or Yorkshire grouse. Suggested management options for the three moors include adopting nontoxic shot for all game shooting on the estates, allowing heather (Calluna vulgaris) vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead.

Lead isotopes in environmental sciences: a review

Lead (Pb) isotopic analyses proved to be a very efficient tool for tracing the sources of local and global Pb pollution. This review presents an overview of literature published on the use of Pb isotopic analyses of different environmental matrices (atmospheric aerosols, lichens, tree rings, peat deposits, lake, stream, marine sediments, soils, etc.). In order to gain more insight, the isotopic compositions of major sources of Pb in the environment as determined by several authors are described in detail. These include, above all, the former use of leaded gasoline, coal combustion, industrial activities (e.g., metallurgy) and waste incineration. Furthermore, this review summarises analytical techniques (especially ICP-MS) used for the determination of Pb isotopes in environmental samples.

Lead Isotopic Compositions of Environmental Certified Reference Materials for an Inter-Laboratory Comparison of Lead Isotope Analysis

Lead isotope ratios, viz. 207Pb/206Pb and 208Pb/206Pb, of the commercially available certified reference materials (CRMs) issued in Japan are presented with an objective to provide a data set, which will be useful for the quality assurance of analytical procedures, instrumental performance and method validation of the laboratories involved in environmental lead isotope ratio analysis. The analytical method used in the present study was inductively coupled plasma quadrupole mass spectrometry (ICPQMS) preceded by acid digestion and with/without chemical separation of lead from the matrix. The precision of the measurements in terms of the relative standard deviation (RSD) of triplicated analyses was 0.19% and 0.14%, for 207Pb/20Pb and 208Pb/206Pb, respectively. The trueness of lead isotope ratio measurements of the present study was tested with a few CRMs, which have been analyzed by other analytical methods and reported in various literature. The lead isotopic ratios of 18 environmental matrix CRMs (including 6 CRMs analyzed for our method validation) are presented and the distribution of their ratios is briefly discussed.