Determination of Metals in Natural Waters by Inductively Coupled Plasma Optical Emission Spectroscopy after Preconcentration on Silica Sequentially Coated with Layers of Polyhexamethylene Guanidinium and Sulphonated Nitrosonaphthols

Figure 8

The effect of sample volume on metal recoveries for SiO₂-PHMG-NRS. Mass of adsorbent in the column 0.1 g, рН 6.5, and flow rate 1.5 mL min⁻¹. Concentration of metals: 200 ng mL⁻¹ of Fe(III), 50 ng mL⁻¹ of Cu(II), Al(III), Zn(II), and 20 ng mL⁻¹ of Co(II), Ni(II), Pb(II).