Optimization of different atomic spectrometric methods for the determination of Se in blood and blood fractions

ETAAS, FIA-ETAAS and HG-ICP-AES methods were applied for measuring selenium in blood and blood fractions. For ETAAS, the temperature program was optimized, namely the ashing, the pretreatment and the atomization steps. For this purpose real blood samples were used as the matrix. Different chemical modifiers were tested. A combination of Pd and Mg(NO3)2 was found to be optimal using a pretreatment temperature of 1100 °C, an ashing temperature of 600 °C and an atomization temperature of 1900 °C. For fractions with low selenium content a multi-fold injection technique was applied. For comparison, measurements by FIA-ETAAS and HG-ICP-AES were performed. They were in good agreement with the results obtained by direct ETAAS measurement. As an application of the method Se was determined in blood and blood fractions (erythrocytes, plasma and lymphocytes) of two groups of people. For the selenium determination in whole blood a detection limit of 0.7 ng ml-1 by ETAAS, of 0.5 ng ml-1 by HG-ICP-AES and of 0.05 ng ml-1 by FIA-ETAAS was obtained.