Silica-immobilized formylsalicylic acid as a selective phase for the extraction of iron(III).

The immobilization of formylsalicylic acid compounds on the surface of amino group-containing silica gel phases is described. The resulting phases were tested for the extraction of iron(III) and showed an exchange capacity of 0.95-0.96 mmol g(-1). The other metal ions tested showed lower metal capacity values than iron(III). The selectivity of the phases tested for the extraction of iron(III) from a mixture containing several other metal ions was evaluated using atomic absorption spectrometry. A method for the recycling of immobilized silica gel after metal extraction is described for practical applications.