SYNTHESIS AND CHARACTERIZATION OF THE SURFACTANT TERBIUM -[[(2-ETHYLHEXYL)OXY]CARBONYL]ETHYL]THIO]SUCCINATE AS A REAGENT FOR DETERMINING ORGANIC ANALYTES

The surfactant terbium s[[(2-ethylhexyl)oxy]carbonyl]ethyl]thio]succin ate has been synthesized and characterized by use of its absorption, l uminescence, and microviscosity properties. In the presence of small a mounts of rater, this surfactant aggregates in cyclohexane to form rev ersed micelles containing Tb(III) counterions. The critical reverse mi celle concentration has been determined to be 5.7 x 10(-5) M with the use of an optical probe. Organic analytes solubilized in reverse micel les hale been detected indirectly with the use of the luminescence cha racteristics of Tb(III) counterions. The detection scheme is based on energy transfer from the solubilized organic donor to acceptor Tb(III) counterions. Analytical figures of merit for the micellar system in t he presence of organic analytes are presented. The microviscosity of t he reverse micellar core has been estimated with the use of a viscosit y-sensitive luminescent probe.