Abstract: A organically modified molecularly imprinted silica (MIS), selective for methylxanthines, was prepared using a simple sol-gel procedure. Caffeine was used as template; 3-aminopropyltrimethoxysilane (APTMS) as functional monomer and tetraethyl orthosilicate (TEOS) as reticulating agent. The material was packed on solid-phase extraction (SPE) cartridges and evaluated with aqueous test samples, natural water and human urine; a quantitative method for methylxanthines in water, using SPE cartridges packed with the MIS coupled with HPLC-UV was developed. The MIS was highly specific for methylxanthines, with an imprinting factor of (20.5 [plus-or-minus sign] 1.9). The analytical method resulted in detection limits of 85 μg L-1 for theobromine, 44 μg L-1 for theophylline and 53 μg L-1 for caffeine
Template and target information: methylxanthines, caffeinr
Author keywords: MIP, sol-gel, Ormosils, caffeine, SPE

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