Direct determination of selenium in serum by electrothermal atomization laser-induced fluorescence spectrometry

A technique for the determination of serum selenium by electrothermal atomi zation laser-induced fluorescence (ETA-LIF) spectrometry is;discussed. Far- UV radiation used for Se excitation at 196.026 nm was generated as the seco nd anti-Stokes stimulated Raman shift of the output of a frequency doubled dye laser operating near 234 nm. Owing to the high spectral selectivity and high sensitivity of the ETA-LIF technique, direct determination is possibl e by using a simple aqueous dilution (1:10 or 1:20) of the serum samples an d a Pd-Mg chemical modifier to reduce pre-atomization losses of the analyte . The accuracy of the method was demonstrated by analysis of NIST SRM 1598 Inorganic Constituents in Bovine Serum (experimental value 42 +/- 3 ng g(-1 ); certified value 42.4 +/- 3.5 ng g(-1)). Analysis of 128 serum samples dr awn from bone marrow transplant patients yielded values of 89 +/- 20 and 92 +/- 23 ng g(-1) for pre- and post-operative samples, respectively.