Optimization of conditions of selenium determination in blood serum by atomic absorption spectrometry

Methods of determination of selenium in samples of dilute and mineralized blood serum by AAS with electrothermal atomization and hydride generation are described. Use of various matrix modifiers (Pd(NO3)(2) + Mg(NO3)(2), Ni(NO3)(2) + Mg(NO3)(2) and Pd + ascorbic acid) and introduction of air into a furnace during pyrolysis are discussed. With hydride generation, the influence of interfering substances (sodium and HNO3 residues after mineralizations) and optimization of the quartz atomization tube temperature are described. For all procedures, the limits of detection, determination and repeatability as well as the results of analysis of a reference material (Seronorm(TM) Trace Element Serum) and of reversibility testing are given.