Preconcentration of lanthanum (III) from aqueous solutions by a solid-phase extraction method using natural nanogeomaterial

The sorption properties of a natural nanomaterial, Transcarpathian clinoptilolite, regardingtrace amounts of La(III) were studied using the solid-phase extraction method under dynamic conditions. The optimal conditions for La(III) sorption were determined as a function of sorbent particle size, pH, and solution concentration, as well as the thermal treatment of the sorbent. The distribution of various forms of La(III) in aqueous solutions at different total lanthanide concentrations was calculated in a wide pH range. The maxi¬mum sorption capacity of natural clinoptilolite for La(III) under optimal conditions is 61.7 mg/g. The most effective desorbents for La(III) are solutions of mineral acids (6 M HCl, 6 M HNO3), as well as 1 M KCl and 1 M NaCl, acidified with HCl solution to a pH of 3.8. A method for concentrating trace amounts of La(III) from aqueous solutions using solid-phase extraction with subsequent determination of this rare earth element by spectrophotometric method has been developed.