Microdetermination Of Mercury Research Articles

Colorimetric Microdetermination of Mercury(II) with Some Quinoxaline Azo Compounds in Presence of an Anionic Surfactant

A new simple, rapid, sensitive, and selective method is proposed for the microdetermination of mercury. Mercury(II) forms insoluble complexes with 2,3-dichloro-6-(2-hydroxy-3,5-dinitrophenylazo)-quinoxaline (1), 2,3-dichloro-6-(5-amino-3-carboxy-2-hydroxy-phenylazo)-quinoxaline (2), 2,3-dichloro-6-(2,7-dihydroxynaphth-1-ylazo)-quinoxaline (3), and 2,3-dichloro-6-(3-carboxy-2-hydroxy-naphth-1-ylazo)-quinoxaline (4) in aqueous acidic medium; the complexes can be made soluble by the action of an anionic surfactant. The solution of the pink coloured compounds is stable for at least 24 h. Beer’s law is obeyed over the concentration range from 0.1 to 2.8 μg · cm−3 of mercury. For a more accurate analysis, Ringbom optimum concentration ranges were found to be 0.25–2.5 μg · cm−3. The molar absorpitivity, Sandell sensitivity, and relative standard deviations were also calculated. A slight interference from Pd2+ and Cd2+ is exhibited by the first three ligands, whereas the last one is only negligibly affected by these metal ions. Strong interference from Ag(I) is evident for all ligands, whereas alkali, alkaline earth, and other transition metals tested posed negligible interference. 15 μg · cm−3 of Cd2+ and Pd2+ or 10 μg · cm−3 of Ag+ can be tolerated if 1.0 mg of potassium bromide and 2.0 mg of citrate as masking agents are added for the determination of 1.5 μg · cm−3 of mercury(II). The method was applied to the determination of methyl- and ethylmercury chloride and the analysis of environmental water samples.

Microdetermination of Mercury in Industrial Waste Waters by Stripping Voltammetry

Low levels of mercury have been determined in industrial waste waters by differential pulse anodic stripping voltammetry with a precision of ±3.6 standard deviation. The limit of determination was observed to be 1.0 μg/L.

New external reagents for the simultaneous microdetermination of carbon, hydrogen and mercury

Non-conventional, extremely cheap and readily available materials, namely zinc plates, pumice granules or polystyrene foam cubes, have been utilized as new external mercury-retentive agents at room temperature for the simultaneous gravimetric microdetermination of mercury, carbon and hydrogen by the rapid straight empty-tube method of Korshun and Klimova. A standard Pregl absorption tube charged with the reagent is connected between the combustion tube and the water-absorption tube. Satisfactory results are obtained for carbon, hydrogen and mercury, and compare reasonably well with those found by using the traditional silver wool or gold sponge under similar conditions. Sulphur or halogen can also be determined simultaneously, as usual.

Microdetermination of mercury by its inhibition of 3α-hydroxysteroid dehydrogenase

A fluorimetric enzymatic method is described for the determination of mercury(II) which inhibits the activity of the enzyme 3α-hydroxysteroid dehydrogenase (3α-HSD). The method is based upon the oxidation of deoxycholic acid by β-NAD + in the presence of the enzyme 3α-HSD. The generated NADH is monitored fluorimetrically. Mercury was determined in the range 5–25 × 10 −8 M with an accuracy of about 5%.

Microdetermination of mercury using silver and copper ion selective electrodes with silver-dithiooxamide and copper-diethyldithiocarbamate loaded polyurethane foams

Microdetermination of Mercury Using Silver and Copper Ion Selective Electrodes with Silver-Dithiooxamide and Copper-Diethyldithiocarbamate Loaded Polyurethane Foams

Studies on mercury pollution: microdetermination of mercury in biological materials by cold vapour atomic absorption spectrometry.

A simple, rapid, precise and accurate method for the determination of mercury in biological material is described. Biological samples were digested with nitric acid and acidified potassium permanganate and determined by cold vapour analyser. The proposed method was successfully employed for the determination of mercury in samples of fish, hair and blood.

Photoacoustic Spectrometry of Solid Samples. III. Microdetermination of Mercury as Hg Diphenylcarbazone Complex

Abstract Photoacoustic spectrometry was applied to the determination of michroamount of Hg diphenylcarbazone complex. The photoacoustic spectrum and diffuse reflectance spectrum almost agree with each other, showing an absorption maximum at 560 nm, as in the absorption spectrum of the complex in benzene solution. Determination of Hg was performed by measuring the intensity of photoacoustic signal at 560 nm. The normalized signal intensity increased linearly with the amount of mercury ion up to 100 ng, deviating from linear relationship downwards above 100 ng. The photoacoustic signal saturation caused by strong absorption of radiation was investigated.

Indirect amplification method for determining mercury by direct-current polarography. Application to organomercury compounds

An amplification method for the determination of 0.5–70 ppm (2.5 × 10 −6 to 3.5 × 10 −4 M) of Hg(II) is described. Hg(II) is reacted with a slight excess of KI, and the excess iodide is oxidized by bromine water and measured polarographically as iodate with sixfold amplification. Alternatively, the iodate formed is reacted to liberate iodine which is then reduced to iodide, and again oxidized to yield six iodate ions for every iodide ion originally present; 2 Microdetermination of Mercury in Organomercurial Compounds Compound Sample (mg) Hg (%) SD (%) Calcd Found Error Phenylmercuric Acetate 4.682 59.57 60.04 +0.47 0.68 3.690 59.08 −0.49 Fluorescein-mercuric acetate 3.000 47.22 47.09 −0.13 0.64 3.325 47.21 −0.01 4.173 46.33 −0.89 Mercurochrome 6.884 26.72 25.73 −0.99 0.59 5.427 26.12 −0.60 3.180 26.74 +0.02 4.903 26.50 −0.22 4.542 26.88 +0.16 polarographic reduction requires 36 electrons. Oxidation of the excess iodide with periodate yields four iodate ions for every iodide ion and therefore allows 24-fold amplification. Microdetermination of mercury in organomercurials is achieved using the sixfold method following closed flask combustion: the average percentage error for 10 determinations is ±0.40 and the time required for one sample run is 45 min.

Extremely selective microdetermination of mercury involving glyoxal-bis(2-thiolanil)

A slight, positive effect of the salt was also observed in the case of determinations of the other two polycarboxylic acids. Different effects of the presence of sodium perchlorate were manifested also when mixtures of the acids were examined. A positive influence was observed, if a mixture of benzoic and succinic acid was titrated, a negative one for the mixture of succinic and sulphosalicylic acids, as can be seen in Figures 3 and 4. o .% A

The microdetermination of mercury and organomercury compounds in environmental materials

The microdetermination of mercury and organomercury compounds in environmental materials

Kinetic microdetermination of mercury in natural waters and biological materials.

A wet digestion has been developed to prepare water and biological samples for a kinetic determination of mercury using an iodide-catalyzed reaction between cerium(IV) and arsenite(III). A mercury-free control, prepared using ion-exchange with a selective chelating resin, was used by adding mercury standards to make a calibration curve. Both inorganic and organic mercury can be determined by the method described either in water or biological samples containing mercury in the range of 0.05 to 2.0μg per ml. The procedure can be used satisfactorily down to the 0.05-ppm level for fresh water and urine with an overall error of less than 5 %. The method can also be employed for the determination of mercury in sea water or blood serum with an error of 10 % or less and gives results which compare favourably with other procedures.

Anticatalytic microdetermination of mercury using cerium-arsenite reaction.

An anticatalytic kinetic method, based on the decreased rate of the reaction between Ce(IV) and As (III), was developed for the determination of mercury. The change in reaction rate due to inhibition by mercury was measured spectrophotometrically at 275 nm. Reaction conditions and interferences of foreign ions were studied. Amounts of mercury in the range 0.04–0.20μg were determined with an overall error of less than 5 % at a reaction time of 25 minutes.

Macro- and microdetermination of mercury(I) using potassium permanganate as an oxidant in acid medium in presence of fluoride ions

Mercurous mercury can be titrated potentiometrically and visually with KMnO 4 in the presence of fluoride and nitric acid. The optimum conditions are 0.2–1.2 N HNO 3 in presence of 1% NaF at temperatures not exceeding 50 °C. The method can be applied for the microdetermination of amounts as small as 0.13 mg of Hg(I) both in HNO 3 and H 2SO 4. The latter acid is preferable.

Microdetermination of mercury in biological samples. II. An apparatus for rapid automatic determination of mercury in digested samples.

Urine samples that have been cold-digested by potassium permanganate-sulphuric acid mixture overnight are analysed in apparatus consisting of an automatic sample changer, pumps for transferring the sample solution to a purgation tower and adding tin(II) chloride solution, which reduces mercury(II) to metallic mercury, and a spectrophotometer. The mercury vapour is liberated from the solution in the tower by a flow of nitrogen and then taken through the absorption cell in the spectrophotometer where the light absorption at a wavelength of 253·7 nm is continuously recorded. After completion of the purgation, the mercury-free solution is transported back to the original tube in the sample changer by reversing the pumps, and the next analysis is started. The mercury content in the sample is calculated from standard graphs drawn from results with known amounts of mercury. Sixty digested samples, each containing 1 ml of urine, are analysed in about 2 hours without any manual work or supervision. In each sample about 1 ng of mercury can be detected, but normally the working range for urine samples is 0 to 400 ng ml–1 of mercury(II). The analysis can be applied to biological or any other samples that can be digested in a similar manner.

Redox reactions on the ring-oven: Part l. Microdetermination of mercury

Redox reactions on the ring-oven: Part l. Microdetermination of mercury

Microdetermination of mercury by the oxygen bomb combustion method

Microdetermination of mercury by the oxygen bomb combustion method

Direct Micro determination of Mercury in Color Additives by the Photometric-Mercury Vapor Procedure

Abstract A direct method has been developed for the determination of submicrogram amounts of mercury in inorganic and organic color additives. Samples are pyrolyzed at 650°C, generating mercury vapor from the mercury compounds present in the sample. The pyrolysate is passed over heated copper oxide and swept through a series of traps that remove interfering substances. The mercury content of the gas stream is determined with a commercially available mercury vapor meter. The method requires no pretreatment of the sample, such as digestion and isolation of mercury. Amounts of mercury as low as 0.01 μg can be detected. Samples as large as 25 mg (organic colors) or 250 mg (inorganic colors) may be used. Mercury at a concentration of 0.50 ppm in organic colors and 0.05 ppm in inorganic colors can be determined to within ± 2 0 % . About 5 minutes is required per analysis. The method is not suitable for the determination of mercury in samples containing organically bound iodine.

Microdetermination of Mercury in Urine by Alkaline Hydrolysis

Microdetermination of Mercury in Urine by Alkaline Hydrolysis

Microdetermination of mercury in biological material

Microdetermination of mercury in biological material

Microdetermination of mercury in biological material: R. Fabre, R. Truhaut, and C. Boudene, Compt. rend.,246, 2086–2090 (1958)

Microdetermination of mercury in biological material: R. Fabre, R. Truhaut, and C. Boudene, Compt. rend.,246, 2086–2090 (1958)