Nanocomposites and nanomaterials

Sorption-luminescence method for determination of neodymium using Na-modified clinoptilolite
E.T. Stechynska1, V.O. Vasylechko1,2, R.V. Gamernyk1, M. Sprynskyy3, B. Buszewski3
1 Department of Analytical Chemistry and Department of Experimental Physics, Ivan Franko National University of Lviv. 1 Universytetska Str., 79000 Lviv, Ukraine
E-mail: vasylechko@ukr.net
2 Department of Sciences and Environmental Protection, Lviv University of Trade and Economics, 9 Samchuka Srt., 79011 Lviv, Ukraine.
3 Department of Environmental Chemistry and Bioanalytics, Nicolaus Copernicus University, 7 Gagarina Str.,87-100 Toruń, Poland

Sorption of determination element on the solid matrix is one of the effective method for increasing sensitivity and selectivity of luminescence (LM) determination. In this case the intermolecular energy transfer is suppressed, that provides to increasing LM intensity and the selective concentration effect is also gained. Promising materials for solid phase spectrofluorometry are natural zeolites activated by REE ions. These inorganic nanomaterials have ability to include lanthanides ions in the grid using exchanged reactions. These ion save their ability to react with organic ligand. The sorbates that have been created on the zeolite surface have the ability to absorb UV–Vis–radiation and intensive LM. The possibility for LM determination of Nd using Na-modified Transcarpathian clinoptiloilite as a sorbent was studied. The Nd(III)–Na-clinoptilolite samples were obtained via lanthanide ions sorption from aqueous solution at pH 6.0 on the Na-modified zeolite in a solid phase extraction mode. The Nd(III)–Na-clinoptilolite samples were pre-calcined at 500C treated by the mixture of xylenol orange and ethonium at pH 8.0 in a static mode. Obtained samples of the Na-clinoptilolite–Nd(III)–xylenol orange–ethonium luminophore were dried at 100C. For the excitation of LM samples rays with the wavelength of 532 nm were used. The intensity of the LM at 875 nm was chosen as analytical parameter for the quantitative determination of Nd. The linear range of determined concentrations of Nd(III) using the proposed sorption-luminescence method remains within 12-250 ng/mL. The limit of detection of Nd(III) is equal to 4 ng/mL. The proposed method can be used for neodymium determination in the presence of many rare earths.