Table 1: Tolerance limits of foreign ions, Amount of Fe(II) taken = 0.558 μg mL−1 pH = 5.0.

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

Sulphate1440Na(I)1565La(III)18
Iodide1303Mg(II)1460Ag(I)15
Phosphate1424Ca(II)1440Hg(II)16
Thiosulphate1424K(I)1300U(VI)6,60a
Tartrate1414Ba(II)1260Mn(II)4,55a
Thiourea1140Pd(II)63Th(IV)3,50a
Bromide1138Cd(II)45In(III)4,60a
Nitrate930Bi(III)42Sn(II)<1,50a
Carbonate900W(VI)37Co(II)<1,55a
Thiocyanate870Hf(IV)36Ni(II)<1,60b
Chloride531Ce(IV)28Zn(II)<1,80b
Fluoride285Cr(VI)27Al(III)<1,45a
EDTA124Mo(VI)22Cu(II)<1,50a
Citrate115Zr(IV)19
Oxalate95Sr(II)18

In the presence of μg of tartrate, μg of thiocyanate.