Phenylmercury Chloride Research Articles

Determination and speciation of mercury in a dental work-place by cold vapour atomic absorption spectrometry and gas-liquid chromatography.

Cold Vapour Atomic Absorption Spectrometry (CVAAS) and Gas-Liquid Chromatography (GLC) have been used for determination and speciation of mercury. Total mercury, methylmercury, ethylmercury and phenylmercury concentrations in urine samples taken from students and staff of a dental work-place were investigated. Air samples were also analyzed. Detection limits, as three times the standard deviation, and in units of ng analyte per ml urine were found to be 1.7, 12, 2.4 and 21 for total mercury, methylmercury chloride, ethylmercury chloride and phenylmercury chloride, respectively.

Determination of low levels of chlorine in adipose tissue by means of the oxygen-flask combustion technique and gas-liquid chromatography

The oxygen-flask technique has been adapted to the determination of low levels of chlorine by employing gas-liquid chromatography. Following combustion and dissolution, chloride in aqueous solution was converted into phenylmercury(II) chloride by treatment at low pH with phenylmercury(II) nitrate. The phenylmercury(II) chloride was extracted quantitatively into toluene and determined by gas-liquid chromatography with an electron-capture detector. The method has been applied successfully to the analysis of rat and mouse adipose tissue, the chloride concentrations of which ranged from 10 to 2800 mg kg–1.

Chemical speciation of mercury in natural waters

Improved sensitivity of the cold-vapour atomic absorption method for mercury can be obtained by equilibrating the reduced sample with a small volume of air at 90°C. An automated system has been developed that has a detection limit of 1 ng Hg l -1. By changing the reducing conditions three species of mercury can be differentiated and determined, inorganic mercury, arylmercury compounds such as phenylmercury(II) chloride, and alkylmercury compounds such as methylmercury(II) chloride. Speciation of mercury in natural waters is possible.

Mechanism of the reaction gas chromatography of phenylmercury(II) compounds

By combining radio-gas chromatography with liquid scintillation counting and with thin-layer chromatography-autoradiography, the conversion of symmetrical phenylmercury(II) compounds into phenylmercury(II) chloride and mercury(II) chloride in gas chromatography in the nanogram range has been demonstrated. The chlorine atoms necessary for this reaction are supplied by the SiCl groups of chlorosilanized materials. The composition of the eluates depends on the concentration of the SiCl groups.

Organosilicon chemistry. Part XVII. Some reactions of 1,1,3,3-tetramethyl-1,3-disilacyclobutane

1,1,3,3-Tetramethyl-1,3-disilacyclobutane. (I), reacts with halogens, hydrogen halides, sulphuric acid, lithium tetrahydridoaluminate, phenyl-lithium, phenylmagnesium bromide, ethanolic silver(I) nitrate, ethanolic mercury(II) chloride, and ethanolic mercury(II) acetate to give ring-opened products in high yields; (I) is unaffected by trifluoroiodomethane, N-bromosuccinimide, benzenethiol, heptan-1-ol, basic alumina, sulphur, phenylmercury chloride, or mercury(II) acetate in benzene. Photochemical reaction of t-butyl hypochlorite with (I) gives comparable amounts of 1 -chloromethyl-1,3,3-trimethyl-, 2-chloro-1,1,3,3-tetramethyl-, and 2,2-dichloro-1,1,3,3-tetramethyl-1,3-disilacyclobutane, together with lesser amounts of the ring-opened hydrogen chloride and chlorine 1 : 1 adducts.

Biliary excretion of phenyl- and methyl mercury chlorides and their enterohepatic circulation in rats

The kinetics of biliary excretion of mercury applied as phenyl mercury (203) chloride (PMC) or methyl mercury (203) chloride (MMC) were studied in rats during the first 24 hours after intravenous administration. The content of total mercury in the bile, plasma, liver, kidneys, gastrointestinal tract, urine, and feces was determined. The enterohepatic circulation of mercury after administration of PMC in rats was compared with that after administration of MMC or inorganic mercury. The differences found in both the kinetics and the distribution of PMC, MMC, and inorganic mercury in rats were discussed.

Characteristics and relationships of mercury-resistant mutants and methionine auxotrophs of yeast.

Approximately one-half of the mutants of Saccharomyces cerevisiae that are selected as resistant to methyl mercury are also found to require methionine. Eighty-four percent of these met mutations occur at the met15 locus, and the remaining 16% occur at the met2 locus. Surprisingly, the methionine-requiring mutants are recovered at a much higher frequency on methionineless media than on media supplemented with methionine. Growth patterns of the met mutants on media having a continuous concentration gradient of methionine and mercury compounds indicate that, at a critical concentration of the mercury compounds, the methionine requirement of certain met mutants is partially or completely alleviated. This was found for met2, met15, and to a lesser extent for met6, but not for any other methionine mutants. This loss of methionine requirement is produced with methyl mercury, phenyl mercury, and mercuric chloride although met2 and met15 strains can be shown to be resistant only to methyl mercury. Other methionine auxotrophs are not resistant to any of the three mercury compounds. The met2 and met15 mutants, but not the other methionine auxotrophs, develop a sheen of an unidentified product when grown on media with mercuric chloride but not with methyl mercury or phenyl mercury. It is suggested that met2 and met15 mutants produce a simple diffusible substance, which detoxifies methyl mercury, which reacts with mercuric chloride to produce a sheen, and which is the cause of the methionine requirement.

Reactions of organic anions : XLIV. Catalytic synthesis of phenyl(trihalomethyl)mercury compounds in aqueous medium

A useful new method of preparation of phenyl(trihalomethyl)mercury compounds has been elaborated. It consists of the reaction of haloforms (chloroform, bromoform, and mixed trihalomethanes) with phenylmercury chloride in the presence of aqueous NaOH/KF solution with a quaternary ammonium compound, triethylbenzylammonium chloride, as a catalyst.

A sensitive method for the ultraviolet spectrophotometric determination of chloride

A new method for the determination of chloride ion is based on the formation of phenylmercury(II) chloride, its extraction into chloroform and reaction with sodium diethyldithiocarbamate to form phenylmercury(II) diethyldithiocarbamate. This complex has spectral maxima at 257 and 297 nm. either of which can he used for quantitative purposes. The molar absorptivities are 21.3·10 3 and 6.5·10 3 respectively. referred to the chloride ion. The method is especially suitable for the determination of trace amounts of chloride in aqueous solution and has been applied to samples of drinking water. Amounts of chloride in the range 0.04 0.32 p.p.m. can be determined in 250-ml aqueous samples with an average relative mean error of 12%. The method can be used also for bromide and iodide, and for organomercury(11) compounds. Interferences are minimal and the method compares favourably with the standard mercury(II) thiocyanate procedure.

The determination of chloride by atomic-absorption spectrophotometry

A method for the determination of trace amounts of chloride ion in aqueous solution is described. The chloride is converted into phenylmercury(II) chloride which is extracted into chloroform and subsequently determined in ethyl acetate solution by means of atomic-absorption spectrophotometry. Alternatively, but less conveniently, the phenylmercury(II) chloride can be extracted into isopropyl acetate and this solution, after concentration, is sprayed into the spectrophotometer. As little as 0·015 p.p.m. of chloride can be detected in a 250-ml sample of water, and 0·1 p.p.m. of chloride can be determined with a relative mean error of 4·6 per cent. Interferences are minimal but bromide, iodide, thiocyanate and cyanide must be absent from the solution. The present method compares favourably with a previously described gas-liquid chromatographic method, and is only slightly less sensitive.

Group IVB organometallic sulphides : III. Cleavage of the germanium-sulphur bond by electrophilic reagents

The germanium—sulphur bond in Bu 3GeSAr is cleaved by electrophilic reagents. Thus halogens and nitrosyl chloride react to give the disulphide, ArSSAr; sulphenyl chlorides, Ar′SCl, give ArSSAr′; sulphur chlorides, SCl 2 and S 2Cl 2, give tri- and tetrasulphides, ArSSSAr and ArSSSSAr, respectively. Metathetic reactions also occur with triphenylmethyl chloride and phenylmercury chloride. The germanium sulphides appear to be less reactive than the corresponding tin sulphides.

A gas chromatographic method for the determination of low concentrations of the chloride ion

A new method for the determination of low levels of chloride is proposed. Chloride in aqueous solution is readily converted to phenylmercury(II) chloride by treatment with phenylmercury(II) nitrate at ca. pH 1.5 and the covalently bound chloride is quantitatively extracted into chloroform. This solution is concentrated by distillation and analysed by gas chromatography. The method is suitable for 0.4–7.0 μg Cl ml −1 of the chloroform extract. As little as 0.008 p.p.m. of chloride in aqueous solutions can be determined when a flame ionization detector is used.

Phenyl-(3)-1,2-dicarbollylmercury anion

The phenyl-(3)-1,2-dicarbollylmercury anion is formed by the action of phenylmercury chloride on disodium (3)-1,2-dicarbollide.

Eradicant action of fungicides applied to dormant peach trees for control of brown rot (Monilinia fructicola)

SummaryThere is evidence to suggest that the eradication of Monilinia fructicola in infected peach peduncles in winter may reduce brown rot during the subsequent season. In a series of experiments, in which treatments were applied in the field and the results assessed in the laboratory, benomyl and arsenic or mercury compounds were more effective in suppressing sporulation from overwintering infections than any of the other materials tested. Benomyl effectively suppressed sporulation from infected peach peduncles and mummified peach fruits and was not phytotoxic. Sodium arsenite was an effective eradicant of M. fructicola in peach peduncles and mummified peach fruit at 0·1% and 0·3%, but it was phytotoxic to both peach and apricot trees at rates as low as 0·01% whether applied in mid-winter or at early bud-swell. Phenylmercury chloride (PMC), mercury acetimide at 0·06% Hg and phenylmercury dimethyldithiocarbamate at 0·015% Hg were effective eradicants. At lower rates the mercurials were unsatisfactory. No...

The examination of organomercury compounds and their formulations by thin-layer chromatography.

Thin-layer chromatographic methods for the separation and identification of organomercury compounds have been developed and applied to the examination of commercial-quality organomercurials and seed-dressing formulations. The organomercury compounds, in the form of their chlorides, are separated on silica gel by continuous development with cyclohexane-acetone (4 + 1), and detected as orange-brown spots by spraying the plate successively with copper sulphate and sodium sulphite-potassium iodide reagents. If organomercury salts other than chlorides are present, they must be converted into the chlorides by adding aqueous sodium chloride solution to the spotting solvent.A method for the semi-quantitative assay of inorganic mercury [as mercury(II)] in the compounds, at levels between 1 and 14 per cent., is also described. The inorganic mercury [as mercury(II) chloride] is separated by using carbon tetrachloride-acetone (7 + 3) as the developing solvent and is determined by visual comparison with standards.Little or no mercury-containing impurity was found in samples of phenylmercury nitrate, phenylmercury acetate and phenylmercury chloride examined, but methoxyethylmercury chloride and ethoxyethylmercury chloride samples contained as many as five mercury-containing impurities and up to 12 per cent. of inorganic mercury compounds.

Resistance to mercury ofPyrenophora avenae(conidial stateHelminthosporium avenae) in New Zealand seed oats

Abstract Each of 53 samples of New Zealand seed oats harvested in the 1966–7 season was examined for the presence of Pyrenophora avenae Ito and Kuribay, before and after treatment with an organomercurial seed dressing. Colonies grew from 27 untreated samples and from eight treated samples. A number of isolates of the fungus were further tested for resistance to mercury by growing them on agar containing different concentrations of mercuric chloride, methoxyethyl mercury chloride, and phenyl mercury chloride. All colonies grew well at low concentrations, and in the case of mercuric chloride. grew better in the presence of small amounts of mercury than in its absence. Results of pot tests for infection after treatment agree well with those from agar plate tests.

Effects of plant growth regulators and other compounds on flow of latex in Hevea brasiliensis

SUMMARYEighty‐nine compounds have been tested for their ability to promote the flow of latex from Hevea brasiliensis after tapping. The twenty‐four substances which showed significant activity were: twelve chloro‐ and fluoro‐phenoxy alkylcarboxylic acids substituted in the 4‐, 2, 4‐ and 2, 4, 5‐ positions, two chlorinated benzoic acids, α‐ and β‐naphthaleneacetic acid, 3‐indolylacetic acid, 2‐methoxy‐4‐diethylamino‐6‐isopropylamino‐1, 3, 5‐ triazine (methoxy‐ipazine), N,N‐diallyl‐α‐chloroacetamide (CDAA), 1,1′‐dimethyl‐4,4′‐bi‐pyridilium‐2A (paraquat), neomycin, dichloro‐m‐xyienol, and phenyl mercury acetate and chloride. Despite the many replications the high variability of the yield data does not allow of a precise classification of the relative activities. The most active compounds were 2, 4‐dichloro‐5‐fluorophenoxyacetic acid and 2, 4, 5‐trichlorophenoxyacetic acid (2, 4, 5‐T), although 2, 4‐dichlorophen‐oxyacetic acid (2, 4‐D) gave increases in yield comparable to those of 2, 4, 5‐T in some of the trials.

Observations on the vapour phase activity of some foliage fungicides

SUMMARYBy means of a Botrytis fabae/Vicia faba bio‐assay technique it has been demonstrated that phenyl mercury chloride, maneb, mancozeb, dichlo‐fluanid and oxythioquinox protect areas of leaf beyond the visible limits of the fungicide deposits. The evidence suggests that the extended areas of protection are due to the release of fungicidal vapours. For a given dose of mancozeb the area of protection was related to the number of conidia of B. fabae dusted on to the leaves and for a given inoculum density it extended with increasing fungicide dose applied in standard drop sizes. When the same dose of fungicide was applied in increasing volumes of water, producing widening areas of deposit, the area of protection also increased. Fungicide deposits aged on leaves for up to 4 weeks continued to release toxic vapours.Contact between the fungicides and leaves or between fungicides and spores was not necessary for the demonstration of the phenomenon since vapours diffused from deposits on glass and inhibited the germination of spores in water droplets placed at a distance from the fungicide source. For a given distance separating the fungicide and the spores inhibition increased with increasing fungicide dose. For a standard fungicide dose, inhibition decreased with increasing distances between the fungicide and the spores. The fungicidal vapours inhibited the germination of spores of test fungi other than B. fabae.The practical implications of these observations are examined in the light of evidence that vapour phase protection can occur on leaves incubated in large cabinets; on leaves pre‐incubated at unsaturated humidities; and on leaves incubated in a moving stream of air.

Glasshouse experiments on apple scab

SUMMARYExperiments with fungicide mixtures used protectively and curatively against apple scab showed no advantage from adding phenylmercury chloride (PMC) to certain protective fungicides. Sulphur fungicides greatly impaired the curative activity of PMC, especially in mixtures applied 24 hr. after infection, but captan showed little and dodine acetate no such effect. PMC, however, contributed appreciably to the curative effectiveness of mixtures with captan or dodine acetate. Commercially prepared mixtures of dispersible sulphur with phenylmercury dimethyldithiocarbamate and of zineb with mancozeb gave promising results, and an experimental mixture of dodine/glyodin acetates at low rates was effective protectively and especially curatively.Dodine acetate, dichlofluanid, lime‐sulphur, and isobutyl‐o‐coumarate showed little translocated activity against scab when applied after infection, and PMC, which earlier showed strong translocated activity when applied in summer before infection, was much less effective when applied in spring 24 hr. after infection.Uncontrolled powdery mildew early in the scab‐incubation period greatly reduced the establishment of scab infection on the test plants (clonal root‐stocks); methods of mildew control in such experiments are suggested.

MERCURY RESIDUES IN APPLES IN RELATION TO SPRAY DATE, VARIETY AND CHEMICAL COMPOSITION OF FUNGICIDE

Mercury was readily translocated to growing fruit of apple trees which had received one cover spray of phenyl mercury acetate between June 14 and August 31. The rate of translocation was less with cover sprays applied near the end of this period. Translocation due to a phenyl mercury acetate cover spray occurred to about the same extent in the apple varieties McIntosh, Cortland, Red Delicious and Gravenstein. In addition to phenyl mercury acetate, a cover spray of phenyl mercury chloride, phenyl mercury dimethyl dithiocarbamate, phenyl mercury triethanol ammonium lactate, phenyl mercury monoethanol ammonium acetate, and mercuric chloride resulted in similar translocation of mercury to growing fruit.