Preparation of bis(1-R-o-carboranyl)mercury by direct mercuration of 1-R-o-carboranes with mercury salts in alkaline solution

Conclusions The 1-R-o-carboranes undergo direct mercuration by HgBr₂ in aqueous alkali solution to give the bis(1-R-o-carboranyl)mercury.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1184–1185, May, 1984.     

Alkalimetric determination of mercury by use of its reaction with 1-mercaptopropan-2,3-diol

The reaction of mercury(II) with 1-mercaptopropan-2,3-diol to form its mercaptide and protons, and alkalimetric titration of the acid produced is proposed as a simple and rapid method for determination of mercury. Any acid already present is first neutralized to Phenol Red indicator after complexation of the mercury(II) with iodide to avoid precipitation of mercuric oxide. Mercury metal, its insoluble salts in both oxidation states, complexes and organomercury compounds have been determined after digestion with nitric acid and persulphate to produce mercury(II). The interference of copper(II) is avoided by its reduction and solvent extraction with 2-benzoxazolethiol. The method is unaffected by the presence of large amounts of halides, oxalate, tartrate, citrate, fluoride, EDTA, thiocyanate and thiourea, which all interefere severely in complexation titrations.     

Concentration of mercury in wheat samples stored with mercury tablets as preservative

Tablets consisting of mercury in the form of a dull grey powder made by triturating mercury with chalk and sugar are used in Indian household for storing food-grains. The contamination of wheat samples by mercury, when stored with mercury tablets for period of upto four years has been assessed by using non-destructive neutron activation analysis. The details of the analytical procedure used have also been briefly described.     

A mercury(II)-radical complex with a 1D ladder structure

Interaction of HgI₂ with a new long rigid nitronyl nitroxide radical ligand, 2-[4-(2-pyridin-4-yl-vinyl)phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (L), leads to the formation of the mercury-radical complex [Hg₂I₄L₂] _n (1). The single crystal structure analysis reveals that 1 exhibits a one-dimensional (1D) ladder structure. Magnetic susceptibility data of 1 were simulated by a uniform chain model composed of the NIT–NIT dimers, indicating that there exist an antiferromagnetic exchange between the nitroxides within the dimer (J ₁ = ?8.41 cm^?1) and a very weak interdimer antiferromagnetic interaction (J _c = ?0.39 cm^?1).     

Optically-active bis(methyl-1-naphthylphenylsilyl)mercury

(+)-Bis(methyl-1-naphthylphenylsilyl)mercury has been prepared, though probably in an optically impure state. Racemization without decomposition takes place at about 150°, and stereospecific cleavages of the Si—Hg bonds are possible.     

Micro-volumetric determination of mercury with thionalide

The authors have elaborated an exact micro-volumetric method for the determination of mercury with thionalide.     

Determination of volatile mercury compounds in air with the coleman mercury analyzer system

A simple but very selective cold-vapour atomic absorption system is described for the determination of volatile mercury compounds at very low levels in ambient air. Three different absorbers are compared: activated charcoal, silver-coated sea sand and gold-coated sea sand. To eliminate interferences, a two-step desorption unit is used. After thermal desorption, the mercury is measured by using a modified MAS-50 spectrophotometer. The effects of flow rate and desorption temperature are discussed. The detection limit is 0.1 ng. Above 1 ng, the reproducibility is about 1%. Calibration is done by injection of elemental mercury vapour. The method with gold-coated sand absorbers is most satisfactory and is suitable for the analysis of ambient outdoor and indoor air. All likely volatile mercury compounds are absorbed, and a wide range of mercury concentrations can be determined. In routine application, one analysis takes about 3 min.     

Determination of total particulate mercury in air with the coleman mercury analyzer system

A simple and rapid cold-vapour atomic absorption system is described for the simultaneous determination of low ambient levels of particulate mercury and volatile mercury compounds. Of the different filters checked for particle collection, quartz fibre filters have the best properties. Sampling characteristics were considered with respect to efficiency, reproducibility and duration of sampling. The homogeneity of the solid mercury deposit on the filter was tested. Possible enrichment during sampling by absorption of volatile mercury compounds and possible mercury losses by volatilization of solid compounds were examined. After sampling the mercury is released by pyrolysis and collected on a gold-coated sand absorber. In order to avoid deactivation of the absorber by condensation of pyrolysis products or interference during the subsequent dcsorption and atomic absorption measurement of the collected mercury, a heated catalytic convertor and two specific absorbers for organic substances are inserted in the analysis line.     

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.     

Preconcentration of inorganic mercury and organic mercury with solvent extraction for neutron activation analysis

A preconcentration method combined with neutron activation technique for the analysis of organic and inorganic mercury in waste water samples at ppb levels is presented. The inorganic mercury is extracted in CCl₄ solution with lead diethyldithiocarbamate reagent and the organic mercury is extracted in C₆H₆ solution. Interfering activities of sodium and bromine are removed from the irradiated samples by this procedure. Two different solvent extraction procedures are also described in detail.     

Possible interferences of mercury sulfur compounds with ethylated and methylated mercury species using HPLC-ICP-MS

The HPLC-ICP-MS coupling technique is able to separate and detect methyl, ethyl and inorganic mercury isotopes specifically. An identification of ethyl mercury(+) is not possible when the widely used sodium tetraethylborate derivatisation method in combination with GC-AFS/AAS or ICP-MS techniques is performed because it contains ethyl groups.An unidentified compound with the same retention time as ethyl mercury was found in the HPLC chromatograms of industrial sewage samples and humic-rich soils of microcosm experiments after applying water vapour distillation. We also observed such unidentified peaks in samples of heavily contaminated sites in Eastern Germany, separated by HPLC fractionation only. In the experiments described, different mercury sulfur adducts were synthesised and tested for their retention times in the HPLC-ICP-MS system. It was found that the compound CH₃–S–Hg⁺ showed the same retention time as the ethyl mercury standard. It is therefore possible that ethyl mercury detected in chromatography by comparison of the retention time could also be due to an adduct of a sulfur compound and a mercury species. CH₃–S–Hg⁺ should be tested in other chromatographic mercury speciation methods for this effect.This work can also be regarded as a contribution to the discussion of artificially occurring methyl mercury in sediments during sample preparation.     

The study of distribution coefficients of silver and mercury with chelating ion-exhange resin Dowex A-1

The distribution coefficients (DC) for HgCl ₄ ^2– , Hg(SO₄) ₂ ^2– , Hg(NO₃) ₄ ^2– , Ag⁺, Ag(SCN) ₂ ^– and Ag(NH₃) ₂ ⁺ between aqueous solutions and Dowex A-1 were measured in varying hydrogen ion concentrations. The DC of Ag⁺ in the NO ₃ ^– media was very low (4 to 6). The DC for the Ag(SCN) ₂ ^– complex decreased as pH increased. The Ag(NH₃) ₂ ⁺ complex had a constant DC of about 65 from pH 8 and above. The trend observed for three mercury complexes in HCl, H₂SO₄ and HNO₃ was similar; the DC decreased steadily from 0.1M to 6M. The HgCl ₄ ^2– complex had the highest DC (9000) while the Hg(NO₃) ₄ ^2– complex had the lowest DC (2000).     

Substoichiometric determination of mercury with cetyltrimethylammonium bromide

A radiometric method based on substoichiometric isotope dilution analysis has been developed for the determination of mercury using cetyltrimethylammonium bromide (CTAB) as the substoichiometric reagent. The method is based on the extraction of mercury as an ionassociation complex of tetraiodomercurate(II) ion with a substoichiometric amount of CTAB in benzene. The calibration graph was found to be linear in the range 0–10 μg Hg (II) in the aqueous phase of 10 ml volume. A detection limit of 0.06 μg·ml⁻¹ could be achieved by the proposed method. The relative standard deviation of the method was found to be 3.0% and the method has been successfully applied to study the determination of mercury in various synthetic mixtures.     

1-Phenylvinyl compounds of lithium,mercury, and thallium

Summary Methods are described for the preparation of 1-phenylvinyl compounds of mercury and thallium from the salts of these metals and 1-phenylvinyllithium. Some chemical properties of these compounds were investigated.     

Substoichiometric extraction of mercury with malonic anilide

Determination of mercury (II) by substoichiometric extraction with malonic anilide into a mixture of ether and MIBK is reported. The method has been applied in the estimation of the metal in industrial effluents.