Simultaneous Determination of Se and Te in Ores by HG-AFS After Online Preconcentration with Nano-TiO2 Immobilized on Silica Gel.

A simple, sensitive and interference-free method was established for simultaneous determination of trace selenium and tellurium in ore samples by HG-AFS, by using nano-TiO2 immobilized on a silica gel packed microcolumn for online preconcentration. Selenium and tellurium were selectively adsorbed to the microcolumn in acidic condition and then completely eluted with 2% (m/v) NaOH solution. The experimental conditions for hydride generation, adsorption, elution and potential interference were investigated in detail.

[Simultaneous Determination of Sn and S in Methyltin Mercaptide by Microwave-Assisted Acid Digestion and ICP-OES].

Methyltin mercaptide is widely used as one of the best heat stabilizer in the polyvinylchloride (PVC) thermal processing due to its excellent stability, good transparency, high compatibility and weather resistance. The content of sulfur and tin significantly affects its quality and performance, so it is of great significance to develop an analytical method for the simultaneous determination of sulfur and tin. Inductively coupled plasma atomic emission spectrometry (ICP-OES) has been a powerful analytical tool for a myriad of complex samples owing to its advantages of the low detection limits, rapid and precise determinations over wide dynamic ranges, freedom from chemical inter-element interferences, the high sample throughput and above all, simultaneous multi-elements analysis.

[Adsorption of heavy metal ions on two types of manganese oxides analyzed by AAS and AFS].

Two types of manganese oxides, the octahedral layer structure (OL) and the octahedral molecular tunnel structure (OMS), were controllably synthesized via a facilely hydrothermal route and used to remove heavy metal ions (Pb2+, Cu2+, Ni2+ , Hg2+) in solutions. The heavy metal ion concentrations before and after adsorption were determined by atomic absorption spectroscopy (AAS) and atomic fluorescence spectroscopy (AFS) to evaluate the material adsorption performance. The competitive adsorption of the four ions (Pb2+, Cu2+, Ni2+, Hg2+) on manganese oxides was also investigated.

[Determination of trace silver in water samples by solid phase extraction portable tungsten-coil electrothermal atomic absorption spectrometry].

A simple method has been developed for the determination of silver in environmental water samples using solid phase extraction with tungsten-coil electrothermal atomic absorption spectrometry. Silica gel was used as an adsorbent and packed into a syringe barrel for solid phase extraction of silver prior to its determination by using a portable tungsten-coil electrothermal atomic absorption spectrometer. Optimum conditions for adsorption and desorption of silver ion, as well as interferences from co-existing ions, were investigated.

Comparative study on inorganic composition and crystallographic properties of cortical and cancellous bone.

Objective: To comparatively investigate the inorganic composition and crystallographic properties of cortical and cancellous bone via thermal treatment under 700 °C.

Methods: Thermogravimetric measurement, infrared spectrometer, X-ray diffraction, chemical analysis and X-ray photo-electron spectrometer were used to test the physical and chemical properties of cortical and cancellous bone at room temperature 250 °C, 450 °C, and 650 °C, respectively.

Results: The process of heat treatment induced an extension in the a-lattice parameter and changes of the c-lattice parameter, and an increase in the crystallinity reflecting lattice rearrangement after release of lattice carbonate and possible lattice water.