Complex Formation in the Modified Xerogel Phase: Study and Application in Analysis

Abstract

The review summarizes the author’s results concerning the complex formation in the phase of modified xerogels synthesized by the sol–gel process for application as sensor materials. The results of studying the complex formation (pH ranges of reactions, light absorption maxima and compositions of complexes, and equilibrium constants) are presented and discussed for 87 systems of two types, that is, immobilized ligand (organic analytical reagent)–metal ion and immobilized metal ion–organic or inorganic compound. The approach proposed by the author to describe the complex formation in the modified xerogel phase is presented. The results of applications of modified xerogels as sensor materials are considered, including their use for determining metal ions; organic compounds; hydrogen peroxide; chloride, fluoride, and oxalate ions in food and hygienic products, pharmaceuticals, biological fluids, and environmental media.