Silica was chemically modified with zirconocenes, namely Cp2ZrCl2, (MeCP)(2)ZrCl2, (iBUCP)(2)ZrCl2 and (nBuCp)(2)ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol-gel method, followed by metallation with ZrCl(4)(.)2THF. According to RBS measurements. metal content was 0.2-0.3 wt% Zr/SiO2 for the grafted systems and 4.5 wt% Zr/SiO2 for the phase prepared by the sol-gel method. The solid phases were evaluated in the adsorption/preconcentration of organochloride (hexachlorobenzene, lindane, heptachlor, heptachlor epoxide, dieldrin and endrin) pesticides from aqueous solution. For comparative reasons, commercial LC-18 phase was also evaluated. Analyte concentration was monitored by GC-ECD. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-A-vis the studied analytes. Recoveries results for both analytes were comparable to those observed in the case of LC-18 in the case of the phases prepared by the sol-gel method. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results. (c) 2006 Elsevier Inc. All rights reserved.