Research Article

Separation and Determination of Fe(III) and Fe(II) in Natural and Waste Waters Using Silica Gel Sequentially Modified with Polyhexamethylene Guanidine and Tiron

Figure 4

Extraction of metal Fe(III) (1) and Fe(II) (2) by SiO2-PHMG-Тiron sorbent and of the sorbent after sorption of Fe(III) (3) and Fe(II) (4) versus pH (0.100 g of the sorbent; μmol g−1; , μg mL−1: 1,0 (1, 2), 0,5 (3, 4); = 10 mL).