Determination of mercury by nondispersive atomic fluorescence spectrometry

A nondispersive atomic fluorescence spectrometer for the determination of mercury by the cold-vapor technique has been developed. The conditions for mercury vapor generation in a hydride generator (the concentration and volume of the reagents, reaction and purge times, and argon flow rate) are optimized for fluorescence measurements. An algorithm is proposed for the calculation of the analytical signal that leads to an increase in the signal-to-noise ratio by a factor of 3 as compared to the conventional procedure. On the basis of the results obtained, procedures for the determination of mercury in soil and semolina samples are developed with a detection limit of 60 pg and RSD = 10%. The accuracy of the determinations is verified by an analysis of standard reference samples of soil and semolina.