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Comparison of Clinical Methods with Isotope Dilution ICP-MS for the New Standard Reference Material 955c Lead In Caprine Blood



Karen E. Murphy, Thomas W. Vetter, Gregory C. Turk, Christopher D. Palmer, Miles E. Lewis, Ciaran M. Geraghty, Patrick J. Parsons, William F. Guthrie


The National Institute of Standards and Technology (NIST) has developed Standard Reference Material (SRM) 955c, a new caprine-based, four-level blood standard with certified blood lead levels (BLLs) ranging from 0.4 µg/dL (0.02 µmol/L) Pb to 45 µg/dL (2.17 µmol/L) Pb. Certified values are based on ID-ICP-MS. Strict control and accurate measurement of the procedure blank was necessary to minimize uncertainty for the lowest level (Level 1) and obtain a relative expanded uncertainty (k = 2) of 2.6 %. Level 1 is intended to represent a baseline BLL and provides a means to define detection levels and validate methods developed to measure background contaminate Pb levels in blood. The standard has been developed in collaboration with the Wadsworth Center, New York Department of Health, which provided values based on GFAAS and ICP-MS. Results from these clinical methods are statistically compared to the ID values. The comparison indicates a small but statistically significant low bias in the GFAAS and ICP-MS data at the higher blood lead levels, but excellent agreement near 10 µg/dL (0.48 µmol/L), the current threshold defined by the U.S. Centers for Disease Control and Prevention (CDC) for public health action and clinical follow up. The Level 1 standard is below the detection limit of the GFAAS method. Comparison of Level 1 results for the ICP-MS method with the ID-ICP-MS values showed the methods were not in disagreement, indicating that the ICP-MS method is very capable of measuring BLLs at environmental concentrations.
Journal of Analytical Atomic Spectrometry


“Blood”, “Lead”, “Reference Material”, “Isotope Dilution”, “Inductively coupled plasma mass spectrometry”, “atomic absorption spectrometry”


Murphy, K. , Vetter, T. , Turk, G. , Palmer, C. , Lewis, M. , Geraghty, C. , Parsons, P. and Guthrie, W. (2009), Comparison of Clinical Methods with Isotope Dilution ICP-MS for the New Standard Reference Material 955c Lead In Caprine Blood, Journal of Analytical Atomic Spectrometry (Accessed April 19, 2024)
Created May 26, 2009, Updated October 13, 2017