Determination of lithium, beryllium, cobalt, nickel, copper, rubidium, caesium, lead and bismuth in silicate rocks by direct atomization atomic absorption spectrometry

Abstract

Optimum experimental conditions for the atomic absorption spectrometric determination of Li, Be, Co, Ni, Cu, Rb, Cs, Pb and Bi by direct atomization of solid silicate rock samples were investigated. A 1.0 mg portion of powdered sample (particle size 0.3–25 µm) was mixed with the same amount of graphite powder and atomized in a miniature graphite cup placed within a graphite furnace according to the heating programme that was established. Calibration was effected using aqueous standard solutions in which 500 ng of K were added for Rb and Cs as an ionization buffer. Results for nine geochemical standard reference rock samples showed good agreement with the recommended values; the correlation coefficient for the found and recommended values was 0.9993. The relative standard deviation (n= 5) was less than 10%.