| dc.description.abstract | The interferent effects of thirty SlX metal salts vit.h
the chromium absorbance in the air-acetylene flame has been
studied. Twelve metal interferents of Fe, Co, Ni, Pd, Ti, V,
Mg, Al, Zr, W, U and Mo were found to have suppressive interference.
The interferents of Zn, Cd, Vm, Pb, Ag, Ce, Cu, Sr,
La, Be, Tl, Li, K, Na were found to have enhancing interference.
The metals of Ba, Ca, Rh, Y, Pt , Si, .Th, Sb, As, Bi were found
to have no effect on chromium absorbance.
The interference does not depend on the boiling point of
the added foreign metal or particle Slze. The suppreSSlve
interference 1S postulated to result from the formation of
mixed oxi cle s or bimetallic species. The enhancing interference
is postu.Ls.t.etdo resul t from the suppression of chromium a om z.a-:
tion.
The effect of the alkali sulphates (potassiwu, sodium,
lith:'.um,and rubidium sulphates) as releasing agents has been
tested ane.results show that they can be used to eliminate
botL suppressive and enhancing interferences.
(B) Complexing qf, antimony and tin metal ions and Consequent determination in the atomic absorption
Spectrophotometry
The atomic absorption spectrophotometric determination of
antimony and tin using an aqueous media is hampered by their metal
hydrolysis and hence the complexing agents have to be added to
their respective solutions to retain the metal ions in aqueous
solutions. The atomic absorption spectrophotometric determination
of antimony is best achieved ip-presence of either ammonlum
fluoride-hydrochloric acid-nitric acid mixture, or in presence of
one of the following complexing agents: tartaric acid, citric acid,
oxalic acid, and 2-mercaptopropanoic acid. The interference effects
of twent;y-nine metals tested is least in ammonium fluoride-hydrochloric
acid-nitric acid mixture, comparable in tartaric acid, citric
acid and 2-mercaptopropanoic acid. Hovev er , the effect is pr-onounced
in oxalic acid. Tin can be successfully determined if any of the
above complexing agents or 6M hydrochloric is added.
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