Atom-trapping atomic absorption spectrometry of arsenic,cadmium, lead,selenium and zinc in air—acetylene and air—propane flames

Atom trapping atomic absorption spectrometry has been applied to the determination of Cd, Pb, Se and Zn in an air—acetylene flame and arsenic in an air—propane flame to yield sensitivities that are, respectively, 18, 48, 3, 80 and 60-fold better than those of the conventional technique. Slitting down the zone of observation above the atom-trap to measure in the region of highest atom density further increases the sensitivity for Cd, Cu, Pb, Se and Zn by factors of 4.5, 2.5, 2.5, 5.5 and 1.5-fold, respectively. The sensitivity for cadmium may be increased 2-fold by precoating the silica collector tube with 1000 ppm vanadium or 3-fold with 1000 ppm copper.