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Showing papers on "Potassium dichromate published in 1996"


Journal ArticleDOI
TL;DR: The data suggest that nearly all the ingested Cr(VI) was reduced to Cr(III) before entering the bloodstream based on comparison to RBC and plasma chromium patterns in animals exposed to high doses of Cr( VI).

113 citations


Journal ArticleDOI
TL;DR: The findings suggest that the dental patient group represents a subgroup with a high frequency of metal allergy and is statistically significant or close to significance for nickel sulfate, potassium dichromate, cobalt chloride, palladium chloride and gold sodium thiosulfate.
Abstract: 397 patients claiming various subjective symptoms related to dental restoration materials have been tested for the presence of metal allergy. The resultant data have been compared with the corresponding allergies of eczematous patients. The frequency difference of metal allergy in the dental group is statistically significant or close to significance for nickel sulfate, potassium dichromate, cobalt chloride, palladium chloride and gold sodium thiosulfate. The findings suggest that the dental patient group represents a subgroup with a high frequency of metal allergy.

90 citations


Journal ArticleDOI
TL;DR: An early step in the reaction of Cr(VI) with Cysteine and cysteine derviatives in aqueous and DMF solutions involves the formation of RS-CrO(3)(-) complexes, which are more stable in DMF than in aQueous solution, and their stability towards reduction in aaqueous solution follows the order cysteined < N-acetylcysteine < gamma-glutamylcy Steine < glutathione.
Abstract: Reaction of potassium dichromate with γ-glutamylcysteine, N-acetylcysteine, and cysteine in aqueous solution resulted in the formation of 1:1 complexes of Cr(VI) with the cysteinyl thiolate ligand....

54 citations


Journal ArticleDOI
TL;DR: The results showed that there was no significant change in DPX observed following either Cr(VI) or Cr(III) ingestion, even though blood and urine chromium measurements indicated systemic uptake of a substantial fraction of the ingested chromium.
Abstract: Increased DNA-protein cross-linking (DPX) in circulating leukocytes has been proposed as a potential biomarker for exposure and genotoxic damage caused by inhalation of certain reactive chemicals, such as hexavalent chromium [Cr(VI)]. This study was designed to determine whether ingestion of a single dose of potassium dichromate alone [Cr(VI)] or potassium dichromate fully reduced to Cr(III) with orange juice (prior to ingestion) causes an increase in DPX of circulating leukocytes in humans. Four adult male volunteers ingested a bolus dose of 5000 micro chromium in a 0.51 volume of water (10 p.p.m.), and blood samples were collected at 0, 60, 120, 180 and 240 min afterwards for analysis of DPX formation in circulating leukocytes. Results were compared to each person's own background concentration of DPX in leukocytes. Blood and urine samples were also collected for up to 2 weeks following the dose to examine the pattern of uptake and excretion of chromium. The results showed that there was no significant change in DPX observed following either Cr(VI) or Cr(III) ingestion, even though blood and urine chromium measurements indicated systemic uptake of a substantial fraction of the ingested chromium. Since Cr(III) does not possess DPX-inducing properties while Cr(VI) does, these results suggest that the Cr(VI) was reduced to Cr(III) intragastrically prior to absorption or that the amount of Cr(VI) absorbed into the blood was insufficient to produce DPX. These results are consistent with prior research that indicated that DPX would not occur following exposure to Cr(VI) except at very high doses.

45 citations


Journal ArticleDOI
TL;DR: The phase diagram for the ternary system K2Cr2O7 + KNO3 + H2O was determined at four temperatures, (10, 20, 30, and 40) °C as mentioned in this paper.
Abstract: The phase diagram for the ternary system K2Cr2O7 + KNO3 + H2O was determined at four temperatures, (10, 20, 30, and 40) °C. In addition, the densities of the saturated aqueous solutions were measured. The experimental results show that, in the temperature range (10 to 40) °C, only potassium nitrate and potassium dichromate were present as solid phases and that the solubility of KNO3 was almost independent of the K2Cr2O7 concentration, whereas the solubility of K2Cr2O7 decreased sharply with increases in the concentration of KNO3.

34 citations


Journal ArticleDOI
TL;DR: Contact sensitization capacity of four metal salts, nickel sulphate (NiSO4), potassium dichromate (K2Cr2O7), titanium chloride (TiCl4) and zirconium chloride (ZrCl4), was evaluated using guinea-pigs and mice and determined the order of sensitization potential was K2Cr 2O7 > NiSO4 > ZrCl 4.

33 citations


Journal ArticleDOI
TL;DR: Adverse effects of metal compounds can be tested on the eukaryotic species of Euglena gracilis used as an intermediate model system between bacterial and animal model.
Abstract: The toxicity of inorganic mercury, nickel, chromium and cadmium on the unicellular photosynthetic flagellate Euglena gracilis, strain Z (E.g.) has been tested. Under the conditions used each metal impaired the growth rate of E.g., and had a very strong effect on cell motility. The degree of cytotoxicity and motility decreased from mercury iodide to cadmium chloride to cadmium nitrate to potassium dichromate to nickel sulfate. No mutagenic effects of the metals investigated have been observed. Adverse effects of metal compounds can be tested on the eukaryotic species of Euglena gracilis used as an intermediate model system between bacterial and animal model.

26 citations


Journal Article
G Kansu1, A K Aydin
TL;DR: The metal alloys which were investigated histopathologically in the first part of this study, were examined with respect to their allergic potentials using the patch test to determine the most vigorous allergic response.
Abstract: The metal alloys which were investigated histopathologically in the first part of this study, were examined with respect to their allergic potentials using the patch test. Results from 60 subjects (aged 17-23) were evaluated following exposure to nickel sulphate, potassium dichromate, silver nitrate, cobalt nitrate, copper sulphate, palladium chloride, platinum chloride and gold chloride. Nickel sulphate produced the most vigorous allergic response whereas gold chloride showed the least of all. The remaining solutions were ranked in decreasing order of severity as follows: potassium dichromate, cobalt nitrate, silver nitrate, copper sulphate, palladium chloride and platinum chloride. Patch testing is indicated in any patient with a history of allergy or sensitivity to a metal. The use of nickel containing alloys in such patients should also be avoided.

26 citations


Journal ArticleDOI
TL;DR: In this paper, the principal inorganic anions (bromide, carbonate, chlorate, chloride, fluoride, nitrate, nitrite, sulfate, phosphate) were separated using a capillary electrophoresis system with indirect UV detection at 260 nm.
Abstract: The separation of the principal inorganic anions (bromide, carbonate, chlorate, chloride, fluoride, nitrate, nitrite, sulfate, phosphate) has been achieved using a capillary electrophoresis system with indirect UV detection at 260 nm. Several types of cationic surfactants (quaternary ammonium, phosphonium or methonium) were tested as electroosmotic flow modifiers and added to a chromatebased buffer prepared from potassium dichromate. The influence of many physicochemical parameters such as nature and concentration of cationic surfactant, buffer pH, dichromate concentration buffer, voltage and temperature upon the migration time of an analyte anion, peak efficiency, asymmetry factor, and finally resolution has been investigated. A linear relationship between the corrected area and the anion concentration in the 2.5–50 ppm range was obtained, thus allowing the quantitative analysis of anions in mineral water. Finally, by increasing the hydrodynamic injection time, the separation of inorganic anions at a low concentration level of 50 ng/ml was achieved without any loss of resolution.

15 citations


Journal ArticleDOI
TL;DR: In a hamster model, contact sensitivity to the metal salt, potassium dichromate, to that of oxazolone, a well-known strong sensitizing agent, is compared and the LLNA is indicated as a feasible sensitization test system.

10 citations


Journal ArticleDOI
01 Jan 1996
TL;DR: Chlorophyll induced significantly higher number of chromosomal aberrations when given alone as compared to distilled water and did not reduce the clastogenic activity of the metal when administered in combination.
Abstract: The comparative efficacy of crude extract of spinach-beet leaves (Beta vulgaris var. benghalensis Hort. Chenopodiaceae) and equivalent amounts of chlorophyll and chlorophyllin in reducing clastogenic activity of a hexavalent chromium compound, potassium dichromate (K 2 Cr 2 O 7 ), was tested in mouse bone marrow cells in vivo. The endpoints monitored were chromosomal aberrations (CA). Mice were fed the crude leaf extract by gavage for 7 consecutive days and then treated with the metallic salt on day 7. In separate sets, chlorophyll extracted from the spinach-beet leaves and a synthetic compound chlorophyllin were administered simultaneously with, before, or after exposure to the chromium compound. Chromosomes were studied from bone marrow cells 24 h after the treatment. Crude leaf extract and chlorophyllin did not induce chromosomal aberrations when given alone. Priming with the crude extract reduced the clastogenic effects of potassium dichromate to the control level. Similar protection was afforded by chlorophyllin when given simultaneously. Chlorophyll, on the other hand, induced significantly higher number of chromosomal aberrations when given alone as compared to distilled water and did not reduce the clastogenic activity of the metal when administered in combination.


Journal ArticleDOI
TL;DR: Partitioning data for hexavalent chromium (Cr(VI)) are presented for systems where thermally sensitive poly-N-isopropylacrylamide (NIPA)-based hydrogels are in contact with aqueous solutions of potassium dichromate (K 2 Cr 2 O 7 ).


Journal ArticleDOI
TL;DR: In this article, the XPS data were collected from a pressed potassium dichromate powder and a small amount of contamination was detected in hydrocarbon and carbide states, and subsurface dissolved O is also apparent.
Abstract: XPS data were collected from a pressed potassium dichromate powder. A small amount of contamination is present in hydrocarbon and carbide states. A small amount of subsurface dissolved O is also apparent. The spectra obtained from the as-received powder indicate that single states of K and Cr are present and therefore these data can be considered to be characteristic of K2Cr2O7.

Journal ArticleDOI
TL;DR: Physical properties and compositions of hard coatings formed by AC process were investigated in comparison with those by DC process in this article, and it was considered, on the basis of AAS, EPMA and SIMS analyses, that this lower hardness is attributable to a smaller amount of aluminum oxide contained in AC process films.
Abstract: Physical properties and compositions of hard coatings formed by AC process were investigated in comparison with those by DC process. Electrolysis was carried out at current density 3 A/dm2 and at bath temperature 10-20°C, using a sulfuric acid solution containing chromic acid ion (potassium dichromate, chrome (VI) oxides and oxide powders (aluminum oxide, glass beads). Addition of both potassium dichromate and glass beads provided the best properties in hardness for the AC process films by their combined effects, while the hardness and abrasion properties were improved by the addition of chromic acid ion and oxide powders. These characteristic features are thought to result from an increase in aluminum content in the film by the addition of chromic acid, and also from the levelling of the film surface caused by the addition of oxide powders. But AC process films generally showed lower hardness than DC process films. It is considered, on the basis of AAS, EPMA and SIMS analyses, that this lower hardness is attributable to a smaller amount of aluminum oxide contained in AC process films.

Journal ArticleDOI
TL;DR: In this paper, a wavelength dispersive X-ray fluorescence spectrometry (XRF) method is described for the analysis of soluble chromium(VI) in chromium plating mist collected from workplace air.

Patent
16 Aug 1996
TL;DR: In this paper, a process for the preparation of bistriphenylsilyl chromate is described, where triphenylchlorosilane, potassium dichromate and any one selected from alkali metal oxides, alkali hydroxides and alkali carbonates are reacted in, as solvent, a mixture of glacial acetic acid and a hydrocarbon solvent at a certain temperature.
Abstract: Disclosed is a process for the preparation of bistriphenylsilyl chromate, wherein triphenylchlorosilane, potassium dichromate and any one selected from alkali metal oxides, alkali hydroxides and alkali metal carbonates are reacted in, as solvent, a mixture of glacial acetic acid and a hydrocarbon solvent at a certain temperature, whereby bistriphenylsilyl chromate having high purity can be obtained with high yield.