A W-Rh coating on the integrated platform of a transversely heated graphite atomizer (platform modifier) and a RhCl 3 solution (analyte/matrix modifier) were combined for the direct determination of selenium in whole blood by electrothermal atomic absorption spectrometry. Samples were diluted 1+4 v/v with a mixture of 0.2% v/v HNO 3 and 0.5% v/v Triton X-100. For the analysis, 12 μl of the resulting sample plus 6 μl of the Rh solution were delivered into the transversely heated graphite atomizer (THGA) platform modified with W-Rh. The combined use of Rh solution with the W-Rh coating was decisive in increasing the maximum pyrolysis temperature of blood selenium up to 1300 o C. Use of W-Rh as a platform modifier increased the tube useful lifetime up to 200% when compared to an untreated platform using a conventional [Pd+Mg(NO 3 ) 2 ] modifier. The accuracy and precision of the method proposed were verified by analyzing serum certified reference material (Seronorm ) and 20 whole blood samples using Pd/Mg(NO 3 ) 2 modifier in untreated platforms; no statistical differences were found between methods by applying the t-test at the 95% level.