Table 7: Tolerance limits of foreign ions, amount of Co(II) taken = 1.767 μg mL−1, pH = 6.0.

Foreign ionTolerance limit (μg mL−1)Foreign ionTole limit (μg mL−1)Foreign ionToler limit (μg mL−1)

Tartrate1707Na(I)1666Au(III)20
Phosphate1425Mg(II)1530Sr(II)18
Sulphate1440Ca(II)1426Mo(VI)15
Oxalate1320K(I)1200Tl(IV)13
Bromide1198Ba(II)1162Pd(II)11,100c
Thiourea1140Hf(IV)72Th(IV)6,60a
Thiosulphate1120Se(IV)64U(VI)5,60a
Nitrate930Cd(II)56Mn(II)5,50a
Chloride525W(VI)55Cu(II)2,50a
Carbonate300Zr(IV)46Ni(II)<1,80b
Fluoride285Pb(II)42Zn(II)<1
EDTA144Hg(II)40Sn(II)<1
Citrate115Cr(VI)26In(III)<1,60a
Bi(III)21Ga(III)<1,50a
Ru(III)21V(V)<1,50b

In the presence of μg of tartrate, μg of oxalate and μg of thiourea.