Experimental parameters of vanadium determination by atomic-absorption spectroscopy with graphite-furnace atomization.
It was found that impregnation of a graphite cuvette (HGA-72) with salts of elements which form stable carbides (Ta, Si Nb, Zr, W, La) decreases the absorbance signal for vanadium. The slope of the atomization curves indicates that formation of vanadium atoms is inhibited, probably by formation of a ternary compound between the impregnating element, vanadium and graphite. On the contrary bigger signals and better repeatability of results may be achieved when the cuvette is coated with pyrolytic graphite and methane is added to the sheath gas. The presence of methane increases the atomization efficiency and compensates for the disadvantageous influence of any air present in the sheath gas.
Hulanicki
A
A
Institute of Fundamental Problems in Chemistry, University of Warsaw, Warsaw, Poland.
Karwowska
R
R
Stanczak
J
J