Application Of Novel Supported Nanometer TiO₂ For Determination Of Heavy Metal By Flow Injection Preconcentration-Flame Atomic Absorption Spectrometry

Nanometer-sized materials,as a new functional materials,are subject to extensive attention in recent years,superior to traditional materials with a series of special performance. One of the specific properties of nanometer-sized materials is that a high percent of the atoms of the nanoparticle is on the surface.The surface atoms are unsaturated and can therefore bind with other atoms,possess highly chemical activity.Nanometer-sized materials for many metal ions have a strong adsorption capacity,which are satisfactory materials for separation and enrichment of trace elements.Recently,flow injection on-line preconcentration system with mini-column widely has been used to determination of trace metal elements in the complex matrix samples owing to that have better precision,lower consumption of reagents,strong against interference and readily automated operation because of its advantages of faster analysis.Flow injection on-line preconcentration and separation combination with flame atomic absorption spectrometry(FAAS) enhance sensitivity and selectivity of FAAS on metal elements. Nanometer materials are as adsorbent for mini-column of flow injection,which has introduced new vitality into the analytic method of flow injection on-line preconcentration and separation combination with FAAS.These kinds of materials possess higher adsorbent capability,lower interference,better stability,combined with metal ions strongly ect.So nanometer materials have great analytical potential as solid-phase extraction adsorbent for determination of trace metals in environmental samples.This paper was to synthesize nanometer TiO₂ by sol-gel method,and loaded it on silica gel and active carbon,respectively;besides nanometer TiO₂ was modified with 1-(2-pyridylazo)-2-naphthol(PAN).Two novel adsorbent materials were synthesized and characterized by IR,XRD,SEM etc,respectively.Adsorbent materials were packed in home-made mini-column,and were applied to determination of Cu and Cd in environmental water sample by flow injection on-line preconcentration system combination with flame atomic absorption spectrometry.