LUMINESCENCE DETERMINATION OF TEMAZEPAM WITH THE USE OF Tb(III) TERNARY COMPLEX

Abstract

Sensitized luminescence of Tb(III) ions has been studied. It has been shown that the intramolecular transfer of excitation energy from the molecule of ligand to lanthanide ion was observed. Spectral-luminescent characteristics of Tb(III) complex with the representative of benzodiazepines drugs temazepam (L) have been investigated. The interaction of the Tb(III) – L complex has been examined by using UV-visible absorption and luminescence spectroscopy. The maximum intensity of 4f-luminescence has been observed in presence of the anionic detergent sodium dodecyl sulfate (DS). The Tb(III) – L – DS complex shows an up to 7,5-fold enhancement of luminescence intensity upon addition of DS. The life time (81 µs) has been found for Tb(III) – L in absence of DS which increase up to 141 µs, in presence of DS. The ternary complex Tb(III):L:DS = 1:1:2 has been proposed for luminescence determination of temazepam as an analytical form. Optimal conditions have been found at concentrations of Tb(III) and L (СTb=1½10-3 mol/l; CL= 1½10-4 mol/l) at pH 7,0. Under these conditions, the luminescence intensity is linearly dependent on the concentration of L between 0,5-20,0 μg/ml. The method for luminescent determination of temazepam has been developed in dosage form – tablets with limit of determination 0,25 mg/ml.

Keywords

• сенсибілізована люмінесценція
• тербій
• темазепам
• різнолігандний комплекс