title: A rapid and reliable method for Pb isotopic analysis of peat and lichens by laser ablation-quadrupole-inductively coupled plasma-mass spectrometry for biomonitoring and sample screening.
abstract: An analytical protocol for rapid and reliable laser ablation-quadrupole (LA-Q)- and multi-collector (MC-) inductively coupled plasma-mass spectrometry (ICP-MS) analysis of Pb isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) in peats and lichens is developed. This technique is applicable to source tracing atmospheric Pb deposition in biomonitoring studies and sample screening. Reference materials and environmental samples were dry ashed and pressed into pellets for introduction by laser ablation. No binder was used to reduce contamination. LA-MC-ICP-MS internal and external precisions were <1.1% and <0.3%, respectively, on both (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios. LA-Q-ICP-MS internal precisions on (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios were lower with values for the different sample sets <14.3% while external precisions were <2.9%. The level of external precision acquired in this study is high enough to distinguish between most modern Pb sources. LA-MC-ICP-MS measurements differed from thermal ionisation mass spectrometry (TIMS) values by 1% or less while the accuracy obtained using LA-Q-ICP-MS compared to solution MC-ICP-MS was 3.1% or better using a run bracketing (RB) mass bias correction method. Sample heterogeneity and detector switching when measuring (208)Pb by Q-ICP-MS are identified as sources of reduced analytical performance.
authors: Department of Earth Science and Engineering, Imperial College London, London, UK. malin.kylander@gmail.com <malin.kylander@gmail.com>
authors: M E
authors: ME
authors: Kylander
authors: D J
authors: DJ
authors: Weiss
authors: T E
authors: TE
authors: Jeffries
authors: B
authors: B
authors: Kober
authors: A
authors: A
authors: Dolgopolova
authors: R
authors: R
authors: Garcia-Sanchez
authors: B J
authors: BJ
authors: Coles
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D007834:Lasers; D007854:Lead / Q000032:analysis*; D008011:Lichens / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D012987:Soil
chemical_list: D012987:Soil; D007854:Lead