Synthesis and characterization of nano-scale Terbium (III)-trimesic acid (TMA)-1,10-phenanthroline(phen) luminescent complex

The nano-scale luminescent complex of Terbium(III)-trimesic acid (TMA)-1,10-phenanthroline(phen) was successfully synthesized by co-precipitation method in this paper. The chemical formula of the synthesized complex was speculated to be Tb(TMA)(phen)(0.0125)center dot 5H(2)O by elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and Fourier-transform infrared spectroscopy (FTIR). XRD pattern of Tb(TMA)(phen)(0.0125)center dot 5H(2)O indicated that it was a new crystalline complex since the diffraction angle, diffraction intensity and the distance of crystal plane were all different from those of the two ligands. TG curve proved that the synthesized nano-scale luminescent complex was stable in the range from ambient temperature to 464 degrees C in air. TEM images showed that the complex was spherical shape with an average size of 40 nm.

Synthesis, crystal structure, and density of (W1-xAlx)C

A new solid solution system of Al in WC, with the stoichiometry of (W1-xAlx)C (x = 0.10, 0.25, 0.50, 0.75, 0.86), has been synthesized by a solid-state reaction between W1-xAlx alloys and carbon at around 1673 K in vacuum. Environment scanning electron microscope, energy- dispersive analysis of X-ray, X-ray photoelectron spectroscopy, and inductively coupled plasma analyses are used to certify the formation of the products. The mechanism of the solid-state reaction is also discussed. (W1-xAlx)C is identified to crystallize in the hexagonal space group P6m2 (No. 187) and belongs to the WC structure type. The atoms of W and Al occupy the same lattice site (la site) in the cell of (W1-xAlx)C. The cell parameters for each specimen in the phase of W-AI-C are quite close to that of WC, while their densities are far lower than that of WC.

Direct patterning of negative nanostructures on self-assembled monolayers of 16-mercaptohexadecanoic acid on Au(111) substrate via dip-pen nanolithography

Both bare and self-assembled monolayer (SAM) protected gold substrate could be etched by allyl bromide according to atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectrometric (ICPMS) analysis results. With this allyl bromide ink material, negative nanopatterns could be fabricated directly by dip-pen nanolithography (DPN) on SAMs of 16-mercaptohexadecanoic acid (MHA) on Au(111) substrate. A tip-promoted etching mechanism was proposed where the gold-reactive ink could penetrate the MHA resist film through tip-induced defects resulting in local corrosive removal of the gold substrate. The fabrication mechanism was also confirmed by electrochemical characterization, energy dispersive spectroscopy (EDS) analysis and fabrication of positive nanopatterns via a used DPN tip.

Microstructure and electrochemical performance of Ti0.17Zr0.08V0.34Pd0.01Cr0.1Ni0.3 electrode alloy

The microstructure and electrochemical performance of Ti0.17Zr0.08V0.34Pd0.01Cr0.1Ni0.3 electrode alloy have been investigated using X-ray diffraction, field emission scanning electron microscopy-energy dispersive spectroscopy, inductively coupled plasma and electrochemical impedance spectroscopy. The alloy electrode has a higher discharge capacity than an AB(5) type alloy within a wider temperature span. The increase of the charge-transfer-resistances, and the dissolutions of V and Zr were responsible for the performance degradation of the alloy electrode.

Major, minor and trace-elemental contents analysis in northeast soybeans by ICP-AES

Major, minor and trace elemental contents in northeast China soybeans were determined by using inductively, coupled plasma atomic emission spectrometry (ICP-AES). Three different sample digestion methods including two wet digestions, HNO3-HClO4 and HNO3-H2SO4 and a dry ash method were compared. Owing to the high oil content in soybeans, long time is needed and access acid should be added, with mixed acid digestion methods, which may result in higher sample blank. Therefore, the dry ask method would be more proper for the pre-treatment of soybean samples. Potassium and phosphorus are major elements in soybeans, so the effect of potassium and phosphorus on the other elements was investigated. Results showed that the potassium and phosphorus did not affect the determination. of other trace elements. There are not significant differences in trace elemental contents for the eleven northeast China soybeans.

Determination of rare and rare earth elements in soils and sediments by ICP-MS using Ti(OH)(4)-Fe(OH)(3) co-precipitation preconcentration

A method was developed for the determination of trace and ultratrace amounts of REE. Cd. In. Tl. Th. Nb, Ta. Zr and Hf in soils and sediments. With NaOH-Na2O2 as the flux. Ti(OH)(4)-Fe(OH)(3) co-precipitation as the preconcentration technique and inductively coupled plasma mass spectrometry (ICP-MS) for measurement, the whole procedure was concise and suitable for batch analysis of multi-element solutions. An investigation was carried out of the Ti(OH)(4)-Fe(OH)(3) co-precipitation system, and the results obtained showed that the natural situation of Ti tightly coexisting with Nb. Ta, Zr and Hf in geological samples plays a very important role in the complete co-precipitation of the four elements. The accuracy of this procedure was established using six Chinese soil and sediment certified reference materials (GSS and GSD). and the relative errors between the found and certified values were mostly below 10%.

Enzymatic and kinetic properties of selenium-containing catalytic antibody with cGPX activity

Three selenium-containing catalytic antibodies mHB4, mHB5 and mHB7 which acted as mimics of cytosolic glutathione peroxidase(cGPX), were prepared by chemically introducing selenium into monoclonal antibodies HB4, HB5 and HB7. HB4. HB5 and HB7 were raised against a GSH derivative GSH-S-DNP dibenzyl ester, The cGPX activity of mHB4, mHB5, mHB7 were 170, 1 867, 32 U/mu mol, respectively. The cGPX activity of mHB5 was 0, 32 fold of natural rabbit liver cGPX and 1. 51 fold of m4A4. About two atoms of selenium existed in each of mHB5 molecule determined by inductively-coupled plasma/mass spectroscopy (ICP-MS), The optimal activity of mHB5 was at between pH 8. 4 and 8, 8, The reaction catalyzed by mHB5 involved a Ping-Pong mechanism. At pH 7. 0 and 37 degreesC, the apparent second-order rate constants for reaction of mHB5 with H2O2 and t-ROOH were as followed: k(+1) (H2O2) = 9. 71 x 10(6) L/(mol min), k(+1)(t-ROOH) = 5. 99 x 10(5) L/(mol.min). Rate accelerations (k(cat)/K-m/k(uncat)) 9. 8 x 10(6) and 3.7 x 10(5) fold those of the uncatalytic reaction were observed.

Effect of LB monolayers on the mixed crystals of Lead and barium sulfate

The effect of LB monolayers on the mixed crystal was investigated by using X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), and Inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results show that LB monolayer has selectivity for the different nucleation ions with equal charge numbers and about the same ion radius. The selectivity is dependent on the head groups of monolayer. The monolayer and the doped ions have also an effect on the crystal morphology. (C) 2000 Published by Elsevier Science B.V. All rights reserved.

Modern spectral estimation of ICP-AES

The inductively coupled plasma atomic emission, spectrometry (ICP-AES) and its signal characteristics were discussed using modem spectral estimation technique. The power spectra density (PSD) was calculated using the auto-regression (AR) model of modem spectra estimation. The Levinson-Durbin recursion method was used to estimate the model parameters which were used for the PSD computation. The results obtained with actual ICP-AES spectra and measurements showed that the spectral estimation technique was helpful for the better understanding about spectral composition and signal characteristics.

Information system for ICP-AES in Windows environment

An information system for inductively coupled plasma atomic emission spectrometry (TCP-BES) in MS Windows environment was developed based on the previous work in the laboratory. The system contains the data of about 28 000 spectral lines and a function of ICP spectral simulation,so it would be very helpful for line selection. The system also contains the Kalman filter and factor analysis programmes written with MS Visual Basic(version 4.0), which can be used for spectral interference correction and peak position optimization. A large amount of real spectral scanning data of rare earth elements were included in the system for user's references. All these characteristics made the system more useful and practical.

Artificial neural network applied to diagnosis of lung cancer

Artificial neural network(ANN) approach was applied to classification of normal persons and lung cancer patients based on the metal content of hair and serum samples obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) for the two groups. This method was verified with independent prediction samples and can be used as an aiding means of the diagnosis of lung cancer. The case of predictive classification with one element missing in the prediction samples was studied in details, The significance of elements in hair and serum samples for classification prediction was also investigated.

Geochemistry of rare earth elements in cobalt-rich crusts from the Mid-Pacific M seamount

Rare earth elements (RFEs) and major elements of 25 cobalt-rich crusts obtained from different depths of Mid-Pacific M seamount were analyzed using inductively coupled plasma-atomic emission spectrometer and gravimetric method. The results showed that they were hydrogenous crusts with average Sigma REE content of 2084.69 mu g/g and the light REE (LREE)/heavy REE (HREE) ratio of 4.84. The shale-normalized PEE patterns showed positive Ce anomalies. The total content of strictly trivalent REEs increased with water depth. The Ce content and LREE/HREE ratios in Fe-Mn crusts above 2000 in were lower than those below 2000 m. The change in RE E with water depth could be explained by two processes: adsorptive scavenging by setting matters and behaviors of REE in seawater. However, the Ce abundance took no obvious correlation with water depth reflects the constant Ce flux. The Cc in crusts existed mainly as Ce(IV), implying that the oxidative-enriching process was controlled by kinetic factors.

The contribution of trace elements from seawater to chimneys: a case study of the native sulfur chimneys in the sea area off Kueishantao, northeast of Taiwan Island

Hydrothermal fluid containing abundant matter erupts from seafloor, meets ambient cold seawater and forms chimneys. So the main matter origins of chimneys are seawater and matter which are taken by hydrothermal fluid from deep reservoir. However, because of seawater's little contribution to the forming of chimneys, it is usually covered by the abundant matter which is taken by hydrothermal fluid. Therefore, chimneys formed in ordinary deep seawater hydrothermal activity, containing complex elements, cannot be used to study the seawater's contribution to their formation. While the native sulfur chimneys, formed by hydrothermal activity near the sea area off Kueishantao, are single sulfur composition (over 99%), and within chimneys distinct layers are seen. Different layers were sampled for trace element determination, with Inductively Coupled Plasma Mass Spectrometry (ICP-MS). By analyzing the data, we consider C-layer (secondary inner-layer) as the framework layer of the chimney which formed early (Fig. 4), and its trace elements derive from hydrothermal fluid. While the trace elements within A, B, D layers have undergone later alteration. A, B layers are affected by seawater and D layer by hydrothermal fluid. The increase of trace elements of A and B layers was calculated using C layer as background. Based on the known typical volume of chimneys of the near sea area off Kueishantao, we calculated the volume of seawater that contributed trace element to chimneys formation to be about 6.37 x 10(4) L. This simple quantified estimate may help us better understand the seafloor hydrothermal activity and chimneys.

Determination of Total Arsenic and Arsenic Metabolites in Human Liver Hepatocytes

The effects of direct sampling and three digestion methods were investigated on the determination of arsenic in Chang liver hepatocytes after ultrasonic disintegration were investigated. The results showed that the efficiency of microwave digestion and obturator digestion was better than cold digestion and direct sampling. The day precision (present as RSD) of microwave digestion and obturator digestion were 2.1% and 1.2% the inter-day precision were 1.2% and 2.0%, respectively. The spike recovery for the total As in the sample is 95.7% - 108.1%. The As detection limits with these four sample treatment methods (including direct sampling) were 0.74 - 0.93 mu g/L. In addition, arsenic speciation in Chang liver hepatocytes was also analyzed using the hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry. The experimental results indicated that dimethylarsinic acid (DMA) and an intermediate metabolite of DMA were found lit Chang liver hepatocytes besides inorganic arsenic (As(III) and As(V)).

铂族元素分析方法研究及其在有关地质问题中的应用

Characterization of Platinum Group Elements (PGE) has been applied to earth, space and environmental sciences. However, all these applications are based on a basic prerequisite, i.e. their concentration or ratio in the research objects can be accurately and precisely determined. In fact, development in these related studies is a great challenge to the analytical chemistry of the PGE because their content in the geological sample (non-mineralized) is often extremely low, range from ppt (10~(-12)g/g) to ppt (10~(-9)g/g). Their distribution is highly heterogeneous, usually concentrating in single particle or phase. Therefore, the accurate determination of these elements remains a problem in analytical chemistry and it obstructs the research on geochemistry of PGE. A great effort has been made in scientific community to reliable determining of very low amounts of PGE, which has been focused on to reduce the level of background in used reagents and to solve probable heterogeneity of PGE in samples. Undoubtedly, the fire-assay method is one of the best ways for solving the heterogeneity, as a large amount of sample weight (10-50g) can be hold. This page is mainly aimed at development of the methodology on separation, concentration and determination of the ultra-trace PGE in the rock and peat samples, and then they are applied to study the trace of PGE in ophiolite suite, in Kudi, West Kunlun and Tunguska explosion in 1908. The achievements of the study are summarized as follows: 1. A PGE lab is established in the Laboratory of Lithosphere Tectonic Evolution, IGG, CAS. 2. A modified method of determination of PGE in geological samples using NiS Fire-Assay with inductively coupled plasma-mass spectrometry (ICP-MS) is set up. The technical improvements are made as following: (1) investigating the level of background in used reagents, and finding the contents of Au, Pt and Pd in carbonyl nickel powder are 30, 0.6 and 0.6ng/g, respectively and 0.35, 7.5 and 6.4ng, respectively in other flux, and the contents of Ru, Rh, Os in whole reagents used are very low (below or near the detection limits of ICP-MS); (2) measuring the recoveries of PGE using different collector (Ni+S) and finding 1.5g of carbonyl nickel is effective for recovering the PGE for 15g samples (recoveries are more than 90%), reducing the inherent blank value due to impurities reagents; (3) direct dissolving nickel button in Teflon bomb and using Te-precipitation, so reducing the loss of PGE during preconcentration process and improving the recoveries of PGE (above 60% for Os and 93.6-106.3% for other PGE, using 2g carbonyl nickel); (4) simplifying the procedure of analyzing Osmium; (5)method detection limits are 8.6, 4.8, 43, 2.4, 82pg/g for 15g sample size ofRu, Rh, Pd, Ir, Pt, respectively. 3. An analytical method is set up to determine the content of ultra-trace PGE in peat samples. The method detection limits are 0.06, 0.1, 0.001, 0.001 and 0.002ng/mL for Ru, Rh, Pd, Ir and Pt, respectively. 4. Distinct anomaly of Pd and Os are firstly found in the peat sampling near the Tunguska explosion site, using the analytical method. 5. Applying the method to the study on the origin of Tunguska explosion and making the following conclusions: (1) these excess elements were likely resulted from the Tunguska Cosmic Body (TCB) explosion of 1908. (2) The Tunguska explosive body was composed of materials (solid components) similar to C1 chondrite, and, most probably, a cometary object, which weighed more than 10~7 tons and had a radius of more than 126 m. 6. The analysis method about ultra-trace PGE in rock samples is successfully used in the study on the characteristic of PGE in Kudi ophiolite suite and the following conclusions are made: (1) The difference of the mantle normalization of PGE patterns between dunite, harzburgite and lherzolite in Kudi indicates that they are residual of multi-stage partial melt of the mantle. Their depletion of Ir at a similar degree probably indicates the existence of an upper mantle depleted Ir. (2) With the evolution of the magma produced by the partial melt of the mantle, strong differentiation has been shown between IPGE and PPGE; and the differentiation from pyroxenite to basalt would have been more and more distinct. (3) The magma forming ophiolite in Kudi probably suffered S-saturation process.