Nanometer TiO2 was successfully immobilized on silica
gel through sol–gel method and used in a microcolumn for
trace metal enrichment. For nanometer TiO2 coated on the
silica surface, the exchange property was preserved. The material
showed relatively high chemical stability towards the
action of acidic solutions. The packed microcolumn used
in proposed procedure did not show any over pressure or
swelling and can be used up to at least 20 adsorption–elution
cycles without decrease in the performance. The proposed
method presented good sensitivity, precision and accuracy
for all analytes analyzed.