Result: We completed the process of testing the lead content in the blood by means of atomic absorption spectrum - graphite furnace technique (GF-AAS) with detection limits (LOD) 5.13 mg / dL, the limit quantification (LOQ) 9.54mg / dL, the recovery reached 94%, repeatability with a coefficient of variation CV<1%, internal reproducibility with a coefficient of variation CV<5% and the value of measurement uncertainty is 14.6%.