The interference due to several cations and anions was studied in detail. For these studies, different amounts of the ionic species were added to a mixture of aluminum and bismuth containing 1 μg mL−1 of each. The starting point was 500 μg mL−1 of interference to a mixture of cations, and if interference occurred the ratio was progressively reduced until the interference ceased. The tolerated limits were taken as those concentrations causing changes no greater than ± 5% in the absorption spectrum of complexes. The tolerance limits for different ions studied are listed in Table 4. As is shown, the method is relatively specific for aluminum and bismuth.

Table 4

The maximum tolerance values of various cations and anions on the measurement of a mixture of 1 μg mL–1 of aluminum and iron

IonsTolerance limit
Ca(II), Mg(II), Ba(II), Sr(II), Na(I), K(I), As(III), Mn(II), Li(I), Tl(I), Rb(I), , Cs(I), Cd(II), , Br, , , , CH3COO, Cl, SCN, , , I, F, , NO2, , , , , 500
Hg(II), Ag(I), Pb(II) 100
Cu(II) 40
In(III), Ga(III), Th(IV) 20
Mo(VI) 10
IonsTolerance limit
Ca(II), Mg(II), Ba(II), Sr(II), Na(I), K(I), As(III), Mn(II), Li(I), Tl(I), Rb(I), , Cs(I), Cd(II), , Br, , , , CH3COO, Cl, SCN, , , I, F, , NO2, , , , , 500
Hg(II), Ag(I), Pb(II) 100
Cu(II) 40
In(III), Ga(III), Th(IV) 20
Mo(VI) 10

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