Determination of blood lead in dried blood-spot specimens by Zeeman-effect background corrected atomic absorption spectrometry

Abstract

A simple procedure for the determination of blood-lead levels in dried blood-spot filter-paper specimens is described. A 3/16 inch dried blood spot was analysed by a method involving extraction of the lead into 1.25%(NH₄)₂HPO₄—0.5% Triton X-100 solution. A matrix-based calibration was used for analysis, with use of a Zeeman-effect background corrected atomic absorption spectrometer. The within-run precision (% relative standard deviation) of the method at the low end of the analytical range was 19% at 0.36 µmol dm^–3 and 14% at 0.60 µmol dm^–3. The accuracy of the method was verified by recovery tests and by comparison with a routine whole-blood method. The mean blood lead level of 425 Toronto newborns was 0.19 µmol dm^–3(range 0–0.75 µmol dm^–3).