Alternatively, a 1 000 mg/l Fe(III) solution can be prepared by dissolving 8,6341 g of ferric ammonium sulphate, (FeNH4(SO4)2·12H2O), in 100 ml of 1 M hydrochloric acid (3.1.2) and making up the volume to one litre with the 1 M hydrochloric acid (3.1.2).
Deze oplossing kan ook worden bereid door 8,6341 g ijzer(III)ammoniumsulfaat, FeNH4(SO4)2·12H2O, op te lossen in 100 ml 1 M zoutzuuroplossing (3.1.2) en hiermee aan te vullen tot 1 l.