A-341 Development and Validation of an ICP-MS Method to Quantify Lead in Dried Blood Spots

Abstract Introduction The CDC estimates that ∼500 000 children in the US between ages 1–5 have unsafe blood lead concentrations (> 3.5 ug/dL). Lead toxicity can affect all bodily systems and be detrimental to children's developing brains nervous systems. Since exposure does not always induce obvious immediate symptoms, screening is an essential tool public health. Recently, there was a point of care device recalled used measure across country. demise this method left gap for nationally. Dried spot (DBS) sampling excellent alternative traditional collections as it cost effective, less contamination prone, invasive, amenable non-standard collection locations. objective study develop accurate precise DBS with intention improving access underserved populations. Methods detected using Agilent7800 ICP-MS. were punched (6mm) extracted into water based diluent containing EDTA, ammonium pyrrolidine dithiocarbamate, tetramethylammonium hydroxide, Triton X-100, ethanol iridium. All sampled from Whatman903 protein saver cards 6mm punch. A 6-point calibration curve made custom UTAK whole controls blank (target concentrations: 0, 1, 7, 14, 60 100 Exact liquid calibrators determined previously validated method. Once determined, 40 uL each calibrator spotted allowed dry at least 24 hours before extracted. Precision three Whole Blood QC (40 uL/spot; punch). Each level run replicates five days. Linearity confirmed by running levels standards Accuracy evaluated Wisconsin Event Proficiency Testing (PT) Samples results compared peer means. For comparison, venous samples collected Royal Blue EDTA metal free vacutainer tubes; directly finger (n = 20). Additional comparison 10) derived Pennsylvania PT program spotting uL. Results interday precision low, mid, high material 5.0%, 7.5%, 3.0% 6.8, 20.7, 35.8 ug/dL, respectively. 1.0–100 ug/dL within allowable nonlinearity 1 or 5.0% (y 1.01x-1.6;R 0.999). 12; range 0.0–38 ug/dL) 10% mean acceptability criteria. Comparison paired had average bias 4.68% (0.31 ug/dL; Y 1.027x + 0.13(R 0.999); 0.1–77.7 Conclusions We developed matrix-matched calibrators. This supports may adequate sample screen could supplement current need additional ways and/or remote