title: Optimization of an acidic digestion method for the determination of total Pb concentration and its isotope ratios in human blood using ICP-QMS.
abstract: Adverse effects of lead (Pb) on human health are observed even at levels below 5 μg/dL, affecting principally the children population and suggesting that there is not a safe exposure level. The determination of Pb isotopic ratios (LIRs) in biological and environmental samples, is an appropriate tool to track and control the exposure sources, because LIRs constitutes the pollutant's isotopic signature and hence can be used to identify sources of Pb emission. This study proposes the optimization of a method in order to significantly reduce the biological samples' matrix interferences, and improves precision and accuracy in the measurements of LIRs. Four total blood digestion methods were evaluated and the results were subjected to statistical methods (ANOVA) determining the combination of HNO3:H2O2(2:1 v v-1)/g from a sample on a hot plate as the best of them. For the method's validation, detection and quantification limits, linearity range, intermediate precision and recovery were evaluated. The total Pb (PbT) and LIRs were performed by ICP-QMS, defining the optimal value of detector dead time (DT), and correcting mass bias and instrumental drift for this matrix. LIRs based on206Pb,207Pb and208Pb were determined at high precision (%RSD 0.03-0.49%), than those involving204Pb (%RSD > 0.8). The optimized methodology can be used to identify pollution sources in blood and environmental samples using LIRs (206Pb/207Pb,207Pb/208Pb,208Pb/206Pb, etc.) in a trustworthy and simple way, with accurate results.
authors.affiliation: a Multidisciplinary Postgraduate Program in Environmental Sciences , Autonomous University of San Luis Potosi , San Luis Potosi , Mexico.
authors.forename: Rebeca Y
authors.initials: RY
authors.lastname: Pérez-Rodríguez
authors.affiliation: b Engineering Faculty , Autonomous University of San Luis Potosi , San Luis Potosi , Mexico.
authors.forename: Javier
authors.initials: J
authors.lastname: Castro-Larragoitia
authors.affiliation: c Chemical Sciences Faculty , Autonomous University of San Luis Potosi , San Luis Potosi , Mexico.
authors.forename: María C
authors.initials: MC
authors.lastname: Alfaro-De La Torre
authors.affiliation: d Center for Applied Research in Environment and Health (CIAAS) , Autonomous University of San Luis Potosi , San Luis Potosi , Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Díaz-Barriga
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000009:adverse effects* / Q000032:analysis*; D006801:Humans; D007554:Isotopes / Q000009:adverse effects* / Q000097:blood*; D007854:Lead / Q000009:adverse effects* / Q000097:blood*; D013058:Mass Spectrometry / Q000379:methods
chemical_list: D004785:Environmental Pollutants; D007554:Isotopes; D007854:Lead
keywords: Blood digestion; ICP-QMS; blood lead; lead isotopic ratios