SOLID-PHASE LANTHANIDE LUMINESCENCE DETECT IN LIQUID-CHROMATOGRAPHY

Terbium ions are immobilized on silica gel through ethylendiaminetetra acetic acid (EDTA) or diethylenetriaminepentaacetic acid (DPTA) ligand s. The resulting materials are utilized as solid-phase detection syste ms in liquid chromatography. Terbium(III) luminescence is observed whe n organic compounds that can transfer energy to TB(III) by an intramol ecular process are present. Peak tailing caused by slow dissociation o f transferring compounds from the Tb(III) is significantly reduced if potassium acetate is added to the mobile phase. The solid phases slowl y turn a bluish-green color unless triethylenetetramine is added to th e mobile phase. The color change is believed to be caused by bonding o f trace amounts of transition metal ions to the solid phase. Detection of carboxylic acid-containing compounds such as indole-2-carboxylic a cid, indole-3-acetic acid, 5-methoxyindole-2-carboxylic acid, kyurenic acid, and quinolinic acid is more sensitive with the Tb-DTPA phase th an the Tb-EDTA phase, whereas than detection of salicyclic acid is mor e sensitive with Tb-EDTA than with Tb-DTPA. The use of time-resolved d etection methods significantly enhances the sensitivity. Linearity, re producibility, limits of detection, and chromotographic separations ar e examined for several compounds.