Phenylmercuric acetate nitrate

Samples of natural water should either be analysed immediately or be stored (not for a very long time) at a decreased temperature to suppress microbial processes. For the determination of nitrate and nitrite it is useful to conserve the samples by addition of 1 ml chloroform or 0.1% phenylmercuric acetate per Utre. To prevent oxidation of sulphide and some other substances in water samples, reductants are added [5, 147]. If the distribution of a species between the f ree ionic form and various complexes is to be studied, as is of ten the case, care must be taken not to shift the equiUbrium by adding substances that would enter into side reactions with the studied species. 

Aryl mercurials that have been used medicinally include phenylmercuric acetate, phenylmercuric nitrate, nitromersol, thiomersal, merbromin (mercurochrome), and mercurobutol. These compounds are variously used as preservatives in drugs, including vaccines, for skin disinfestation, the treatment of infections of the skin and mucosa, and in contraceptive jellies and hemorrhoidal remedies they have also been used in some cosmetics. The aryl mercurials are better absorbed across the mucous membranes than most inorganic mercury salts. 

In Table 1.3.2 a method for the analysis of nitrates and nitrites for a wide variety of samples is given Aqueous nitrate ions are converted to nitrobenzene by reaction with benzene in the presence of concentrated sulfuric acid as catalyst. The special methods for the different materials are described. To stabilize samples against bacterial action, which can reduce nitrate concentrations, phenylmercuric acetate is added after collection ° Other inorganic compounds in the trace levels for gas-chromatographic determination are, for example, water and carbon monoxide, which were determined in organic solvents or air in the ppb-range ... 

Phenylmercuric acetate is used as an alternative antimicrobial preservative to phenylmercuric borate or phenylmercuric nitrate in cosmetics (in concentrations not exceeeding 0.0065% of mercury calculated as the metal) and pharmaceuticals. It may be used in preference to phenylmercuric nitrate owing to its greater solubility. 

Antimicrobial activity phenylmercuric acetate is a broad-spectrum antimicrobial preservative with slow bactericidal and fungicidal activity similar to phenylmercuric nitrate see Phenylmercuric Nitrate. 

Phenylmercuric acetate is mainly used as an antimicrobial preservative in topical pharmaceutical formulations. A number of adverse reactions to mercury- containing preservatives have been reported see Phenylmercuric Nitrate. 

Phenylmercuric acetate is no longer permitted to be used as a pesticide in the USA. It is, however, included in the FDA Inactive Ingredients Guide (ophthalmic preparations), and is also included in nonparenteral medicines licensed in the UK. In France, a maximum concentration of 0.01% is permitted for use in pharmaceuticals. The use of phenylmercuric acetate in cosmetics is restricted in the UK see Phenylmercuric Nitrate. Included in the Canadian List of Acceptable Non-medicinal Ingredients (however, there must be no other suitable preservatives available). 

Phenylmercuric borate is used as an alternative antimicrobial preservative to phenylmercuric acetate or phenylmercuric nitrate. It is more soluble than phenylmercuric nitrate and has also been reported to be less irritant than either phenylmercuric acetate or phenylmercuric nitrate. See Table I. 

Phenylmercuric salts are active over a wide pH range against bacteria and fungi and are usually used in neutral to alkaline solutions, although they have also been used effectively at slightly acid pH see Section 10. In acidic formulations, phenylmercuric nitrate may be preferred to phenylmercuric acetate or phenylmercuric borate as it does not precipitate. 

Sodium alginate is incompatible with acridine derivatives, crystal violet, phenylmercuric acetate and nitrate, calcium salts, heavy metals, and ethanol in concentrations greater than 5%. Low concentrations of electrolytes cause an increase in viscosity but high electrolyte concentrations cause salting-out of sodium alginate salting-out occurs if more than 4% of sodium chloride is present. 

Phenylmercuric acetate phenylmercuric borate phenylmercuric nitrate. 

Organic Mercury. Case report studies suggest that dermal exposure to methylmercury or phenylmercury in humans can cause rashes and blisters on the skin (Hunter et al. 1940 Morris 1960). A 33-year-old male worker exposed to methylmercury nitrate dust for 2 years developed bums and blisters on his forearm (Hunter et al. 1940). These effects healed within 9 days. Sensitivity to phenylmercuric salts is shown by individuals who developed itchy, pruritic, papular eruptions or rashes on their skin following acute dermal exposure (Morris 1960). A 54-year-old woman with a family history of atopy was found to display erythema (at 30 minutes postexposure) and urticaria (at 60 minutes) when treated topically with a 0.01% solution of phenylmercuric acetate (Torresani et al. 1993). This positive reaction was associated with aggravation of facial edema and an attack of bronchospasm. The woman, who was a farmer, was believed to have been previously exposed to phenylmercuric acetate during contact with pesticides and herbicides used on farm crops. 

Discontinued applications. The use of phenylmercuric acetate as a fungicide in interior latex paints was banned in 1990 (Reese 1990), and its use in exterior paint was banned in 1991 (Hefflin et al. 1993). Both of these bans were prompted because of releases of mercury vapors as the paint degraded. Alkyl mercurial compounds were used until the mid-1970s as a treatment to disinfect grain seeds. Most other agricultural applications of mercury compounds in bactericides and fungicides have been banned due to the toxicity of mercury. Mercuric nitrate was used in the production of felt hats to hydrolyze rabbit fur. The use of mercury as a wood preservative has ceased due to the use of polyurethane (Drake 1981). 

Phenoxyethanol Phenylmercuric acetate Phenylmercuric borate Phenylmercuric nitrate Phenylmercuric nitrate, basic Potassium benzoate Potassium lactate Potassium sorbate Propionic acid Propylparaben... 

Octoxynol-16 Octoxynol-20 Octoxynol-30 Octoxynol-40 Octoxynol-70 Phenylmercuric acetate Phenylmercuric nitrate... 

Phenylmercuric acetate, 0.01% aq (germicidal agent) (type-I and type-IV allergy Torresani et al. 1993) Phenylmercuric nitrate, 0.05% petrolatum (germicidal agent)... 

Examples of preservatives are phenylmercuric nitrate or acetate (0.002% w/v), chlorhexidine acetate (0.01 % w/v), thiomersal (0.01 % w/v) and benzalkorrium chloride (0.01 % w/v). Chlorocresol is too toxic to the comeal epithehum, but 8-hydroxyquinoline and thiomersal may be used in specific instances. The principal considerahon in relation to antimicrobial properties is the activity of the bactericide against Pseudomonas aeruginosa, a major source of serious nosocomial eye infections. Although benzal-konium chloride is probably the most active of the recommended preservatives, it cannot always be used because of its incompatibility with many compounds commonly used to treat eye diseases, nor should it be used to preserve eye-drops containing anaesthetics. Since benzalkonium chloride reacts with natural mbber, silicone or butyl rabber teats should be substituted. Since silicone mbber is permeable to water vapour, products should not be stored for more than 3 months after manufacture. As with all mbber components, the mbber teat should be pre-equilibrated with the preservative prior to... 

Of the mercurial preservatives, thimerosal is less subject to degradation into toxic mercury than either phenylmer-curic acetate or phenylmercuric nitrate. Thimerosal is most effective in weakly acidic solutions. Some patients, however, develop a contact sensitivity and must discontinue use after several weeks or months of exposure. Because thimerosal affects internal cell respiration and must be present at high continuous concentrations to have biologic effects, its dilution by the tear film prevents short-term epithelial toxicity on single appUcation. It has no known effects on tear film stability. A concentration of 1% thimerosal is required to equal the effects on corneal oxygen consmnption of 0.025% BAG. 

Phenylmercuric nitrate is readily formed by heating benzene with mercuric acetate, and treating the resulting acetate with an alkali nitrate. 

The organomercurial derivatives thiomersal and phenylmercuric nitrate or acetate (PMN or PMA) (Fig. 17.6) are bacteriostatic and are primarily employed as preservatives. Use of both compounds has declined considerably due to concerns about mercury toxicity and risk of hypersensitivity or local irritation. They are absorbed from solution by rubber closures and plastic containers to a significant extent. 

All the diarylstibinic acids are solids, and their method of preparation has an influence upon their solubility, eg, the hydrolysis of di-phenylstibinic chloride by ammonium hydroxide yields an acid which is insoluble in ammonium hydroxide or sodium carbonate, but dissolves in sodium hydroxide, whilst solution of the chloride in sodium hydroxide gives a stibinic acid on acidification with acetic acid which dissolves in all the foregoing alkalis. The secondary acids also differ from the primary acids in their action towards hydrochloric acid and ammonium chloride diphenylstibmic acid is insoluble in concentrated hydrochloric acid, and m hot dilute hydrochloric acid its solutions do not give a double salt with ammonium chloride, but pyridine hydrochloride precipitates diphenylstibmic chloride as a double salt. Nitration of the secondary stibinic acids yields nitro-acids containing the nitro-group in the meia-position to the antimony. Reduction of the secondary acids yields stibinoxides. Mercuric chloride converts diphenylstibmic acid in methyl alcohol-hydrogen chloride solution into phenylmercuric chloride and antimony trichloride. 

Laurylpyridinium bisulfate Methoxyethanol Myristalkonium chloride Nitrosophenylhydroxylamine ammonium salt PCA ethyl cocoyl arginate Phenylmercuric nitrate Phenylmercuric nitrate, basic Phenylmercuric oleate Silver nitrate Sodium arsenate Sodium hypochlorite Sodium lauroamphoacetate Sodium oleoamphopropionate Stearamine 2,2 -Thiobis (4,6-dichlorophenol) 3,5,5-Trimethylhexan-1-ol germicide (duckweed killer), petroleum Stearamine acetate... 

The formic acid may be replaced by acetic acid according to Chambers, with the advantage that phenylmercuric nitrate is soluble in the latter and hydrolysis is rapid. Two volumes of glacial acetic acid and 1 volume of water is a suitable solvent and zinc filings are preferable to the powder. 

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