Adsorption of aqueous Hg (II) by a novel poly(aniline‐co‐o‐aminophenol)/mesoporous silica SBA‐15 composite

A novel poly(aniline‐co‐o‐aminophenol) (PAOA)/mesoporous silica SBA‐15 nanocomposite was synthesized and investigated for adsorption of Hg (II) from aqueous solutions of wide pH range. A chemical oxidation method was employed for polymerization of aniline and o‐aminophenol on an ordered SBA‐15 template to obtain a significantly enlarged BET surface area of the adsorbent. Efficiency study revealed that the PAOA/SBA‐15 could reach a maximum Hg (II) adsorption capacity of over 400 mg/g. Kinetic study showed that the Hg (II) adsorption by the PAOA/SBA‐15 fitted a pseudo‐second‐order kinetic model, indicating that the mercury adsorption process was predominantly controlled by chemical process. The results of this study also proved that the adsorbed Hg (II) could be effectively desorbed from the PAOA/SBA‐15 in 0.1M HCl and 5% sulfocarbonide solutions. Associated adsorption mechanism was also investigated by means of Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) techniques. Copyright © 2010 John Wiley & Sons, Ltd.     

A Novel “Turn On” Glucose-Based Rhodamine B Fluorescent Chemosensor for Mercury Ions Recognition in Aqueous Solution

A novel “turn-on” fluorescent sensor based on glucose and rhodamine B for detection of mercury ions was designed and synthesized. The fluorescent sensor showed an extreme specificity for mercury ions than for other metal ions in aqueous solution. On adding mercury ions to the solution of glucose-based rhodamine B sensor, the absorption and fluorescence signals enhanced remarkably at 567 and 587 nm, respectively. Titration of sensor with mercury ions showed 1:1 stoichiometric reaction. The cyclic voltammetric measurement of an increasing amount of mercury ions in the solution of glucose-based rhodamine B sensor commendably showed the change in the fluorescence characteristics. Furthermore, the successful detection of trace amount of mercury ions in water indicated that glucose-based rhodamine B sensor can be used for the detection of the limited mercury ions in drinking water.     

AFS-230E型原子荧光光度计测汞时盐酸引起的故障及故障排除

用AFS-230E型厦子荧光光度计测定汞时，使用相同规格但不同厂家生产的盐酸对测定结果影响较大。使用该仪器测汞时由于配制载流液时选用盐酸不当发生空白值过高的现象，影响汞的准确测定。在排除其它可能故障后，更换不同厂家生产的盐酸进行试验，选用汞空白值低的盐酸，故障排除。     

Mechanism of mercury monomethyl cation detoxication in the interaction with 1-chloro-2,2-propane dithiol

The potential interaction surface between polyhydrated monomethyl mercury cation and 1-chloro-2.2-propane dithiol has been studied by quantum chemical methods. The system generates the hydroxonium cation due to the interaction, which is a demethylating agent for methylmercury. The total thermal balance of the demethylation reaction is 244.5 kJ/mol, the activation energy of the limiting stage in the process has a value of 39.1 kJ/mole.     

Kinetics of Central Ion Electroreduction in Cerium (IV)-Decatungstate

A general characteristics is given to the kinetics of electroreduction of cerium-decatugstate anions on mercury, polycrystalline gold, and the pyrolytic-graphite basis plane in acetate buffer solutions (pH 3.5-6.0). Based on the analysis of UV absorption spectra, the ratio of two reactant forms differing in the protonation degree in solutions under study is estimated. At a negatively charged mercury electrode, the reduction of the Ce(IV) central ion is shown to proceed as an outer-sphere process with classical manifestations of the psi-prime effect (polarization curves reveal a current minimum which deepens with supporting electrolyte dilution and an increase in the reactant negative charge). On the positively charged surface, the current is observed to increase with an increase in the supporting electrolyte concentration, which is interpreted in terms of the strong adsorption of the reactant and its coadsorption with cations. The gold electrode demonstrates pronounced effects of strong chemisorption. Adsorption complications observed on pyrolytic graphite are shown to become strongther for surfaces with more pronounced nonideal behavior. For low concentrations of atomar steps (apparently, for low coverages of pyrolytic-graphite surface with the adsorbed reactant), the quasireversible electron transfer with the rate increasing with increasing pH is observed.     

球形汞膜电极倒导数恒电流溶出分析法研究

本文推导并验证了球形汞膜电极倒导数恒电流溶出分析法理论。确定其理论的应用条件为汞膜厚度不超过4.6×10~(-4)cm,探讨了噪音对灵敏度的影响。     

一组新型络合物晶体结构与光学性能的研究

研究了二氯三烯丙基硫脲合镉(ATCC),二氯三烯丙基硫脲合汞(ATMC)和二溴三烯丙基硫脲合镉(ATCB)三种晶体的结构特点.首次报道了ATMC和ATCB晶体的非线性光学系数及倍频性能;文中分析比较了三种晶体的非线性光学性能;讨论了晶体结构与性能的关系,为探索高效非线性光学新材料提供依据.     

An infrared study of the chemistry of methyl species on Pt(111) formed by the decomposition of dimethylmercury

The chemistry of dimethyl mercury on a Pt(111) single crystal surface has been investigated by reflection-absorption infrared spectroscopy (RAIRS). Dimethyl mercury appears to be highly reactive on Pt(111) and readily decomposes on the surface at temperatures of 100 K and above. Adsorption at 100 K initially occurs in a dissociative manner to produce CH₃ and CH₃Hg species on the surface, both of which are identified as having C_3v local symmetry. At higher exposures, molecular adsorption dominates with the Hg---C---Hg axis initially oriented parallel to the surface. This preferred orientation, however, does not persist into the multilayer. Thermal treatment of the surface layer results in multilayer desorption between 130 and 135 K, and no parent molecular species are observed beyond 160 K. Adsorption at 200 and 300 K produces an overlayer consisting primarily of CH₃Hg species, which are thermally stable to about 350 K. Subsequent heating to 400 K results in the formation of ethylidyne species which are characterised by RAIRS. Adsorption at 400 K results in the direct formation of an ethylidyne layer estimated to be about 85% of saturated coverage.     

Gewinnung und Charakterisierung von nichtkeratinarmer Wolle — ein Modellpräparat für die Grundlagenerforschung von textilchemischen Ausrüstungsprozessen

The nonkeratinous proteins of wool can be partly or completely dissolved by controlled enzymatic digestion. A comparison between the keratose content of intact wool and that of wool which has been hydrolysed for 96 h with pronase confirms that specifically all the nonkeratinous components are dissolved out of the wool composite by pronase. The influence of microbial infection can be excluded.The residue of wool after the hydrolysis, i. e., a wool low in nonkeratinous proteins, has a higher internal volume, as measured by mercury porosimetry. The centrifugal swelling test shows that these wool samples also have increased hygroscopy.

     

Speciation of trace metals in environmental samples at the fisheries laboratory,Burnham on crouch

The methods used by the MAFF Directorate of Fisheries Research for analysis of organometallic compounds are described. These analytical techniques are used for determination of trace quantities of the compounds in water, sediment and biota in UK estuaries and coastal waters.