Spectrophotometric Determination of Iron(II) after Solid Phase Extraction of Its 2,2′ Bipyridine Complex on Silica Gel-Polyethylene Glycol

Table 2

The effect of different ions on the determination of 50 ng mL⁻¹ of iron(II).

Foreign ions	Tolerance ratio [ion]/[Fe^2+]
K^+, NO3^−, SCN^−, NO2^−, Br^−, Mg^2+, Cl^−	1000
Pb^2+, I^−, Ca^2+, F^−	500
Cd^2+, Ba^2+, Cr^3+, Th(IV)	100
Ni^2+, Hg^2+	10
Al^3+, Cu^2+, Co^2+	5