[Preconcentration of Trace Cu(II) in Water Samples with Nano-Sized ZnO and Determination by GFAAS].

The content of copper in natural water is very low, and direct determination is difficult. Therefore, it is very meaningful for the combination of efficient separation-enrichment technology and highly sensitive detection. Based on the high adsorption capacity of Cu(II) onto nano-sized ZnO, a novel method by using nano-sized ZnO as adsorbent and graphite furnace atomic absorption spectrometry as determination means was in this work.

β-Cyclodextrin's orientation onto TiO2 and its paradoxical role in guest's photodegradation.

This work revealed that β-cyclodextrin was attached onto the surface of TiO(2) predominately by its secondary ring side, which caused paradoxical functions of β-cyclodextrin in the photodegradation of the four bisphenols. The equilibrium between the guest adsorbed through β-cyclodextrin onto TiO(2) and the one locked in β-CD in water could also change the role of β-cyclodextrin in the degradation of a certain guest.

[Preconcentration of ultra-trace germanium in water samples with nano-sized TiO2 colloid and determination by HGAFS with colloid sampling].

A novel method for preconcentration of ultra-trace germanium and determination by hydride generation atomic fluorescence spectrometry (HGAFS) was presented in this work. When the pH values of solution were 6.0-8.

Preconcentration and speciation of ultra-trace Se (IV) and Se (VI) in environmental water samples with nano-sized TiO2 colloid and determination by HG-AFS.

A united method for speciation analysis of Se (IV) and Se (VI) in environmental water samples was developed using nano-sized TiO(2) colloid as adsorbent and hydride generation atomic fluorescence spectrometry (HG-AFS) as determination means. When the pH values of bulk solution were between 6.0 and 7.

Preconcentration of trace arsenite and arsenate with titanium dioxide nanoparticles and subsequent determination by silver diethyldithiocarbamate spectrophotometric method.

A novel method of preconcentration of trace arsenite and arsenate by using titanium dioxide nanoparticles as adsorbent was described. The concentrations of preconcentrated arsenite and arsenate were determined by a silver diethyldithiocarbamate spectrophotometric method without desorption. Batch adsorption experiments were carried out as a function of the pH, contact time, amount of titanium dioxide nanoparticles, and solution volume.

[Preconcentration of trace Pd (II) on crosslinked chitosan and determination by graphite furnace atomic absorption spectrometry].

A novel crosslinked chitosan(CCTS) not dissolved in acidic or alkaline solutions was synthesized by the crosslinking reaction of chitosan (CTS) with crosslinking agent (3-chloro-1,2-epoxypropane). The adsorption capability of Pd(II ) by CCTS was studied at different pH value. The results showed that the adsorption efficiency was above 98% after preconcentration for 20 minutes when pH values were 1-4.

Speciation of antimony by preconcentration of Sb(III) and Sb(V) in water samples onto nanometer-size titanium dioxide and selective determination by flow injection-hydride generation-atomic absorption spectrometry.

A novel method for prevention of the oxidation of Sb(III) during sample pretreatment, preconcentration of Sb(III) and Sb(V) with nanometer size titanium dioxide (rutile) and speciation analysis of antimony, has been developed. Antimony(III) could be selectively determined by flow injection-hydride generation-atomic absorption spectrometry, coexisting with Sb(V). Trace Sb(III) and Sb(V) were all adsorbed onto 50 m g TiO2 from 500 ml solution at pH 3.

[Adsorption of p-nitrophenol by nanosized titanium dioxide surface modified with 3,5-dinitrosalicylic acid].

Nanometer size titanium dioxide modified with 3,5-dinitrosalicylic acid (3,5-DA) was prepared using chemical adsorption method. The influences of surface modification on the adsorption of p-nitrophenol (PNP) and the dispersion in solvent such as water, benzene and ethanol were studied. The 3,5-dinitrosalicylic acid is bonded to the surface hydroxyl from TiO2 nanoparticles, results in the formation of a stable, six-ring complex which color is buff.