Showing papers on "Potassium dichromate published in 1987"
TL;DR: In this article, the interaction between potassium dichromate and ascorbate anion in aqueous solution at pH 7.5 has been studied and it is suggested that TRI-HCl is an unreliable buffer in such systems.
83 citations
TL;DR: The results demonstrate that injury to specific regions of the proximal tubule by these agents relates to an innate susceptibility of the intoxicated cell type independent of physiologic feedback or blood delivery patterns proposed as mechanisms of selective injury from in vivo studies.
61 citations
TL;DR: A rapid spectrophotometric method based on oxidation with dichromate for 15 min in 6M sulphuric acid at 80 degrees , and measurement (at 580 nm) of the chromium(III) formed, applied to the determination of paracetamol in drugs prescribed for colds, coughs and flu.
24 citations
TL;DR: The genotoxic activity of NTA, which is a substitute for polyphosphates in household laundry detergents, as well as the interactions between NTA and soluble (potassium dichromate) and insoluble (lead chromate) Cr(VI) compounds in the induction of gene mutations and DNA damage in bacteria were investigated.
Abstract: The genotoxic activity of NTA, which is a substitute for polyphosphates in household laundry detergents, as well as the interactions between NTA and soluble (potassium dichromate) and insoluble (lead chromate) Cr(VI) compounds in the induction of gene mutations and DNA damage in bacteria were investigated NTA did not induce point mutations in S typhimurium TA100 strain, independently of the presence of rat liver metabolic activation, nor did it modify the direct mutagenicity of potassium dichromate Insoluble lead chromate was instead clearly mutagenic in the Salmonella/microsome assay only in the presence of NTA, and the levels of mutagenicity correlated very well with the amounts of Cr(VI) solubilized by NTA in the form of chromate ion, as determined by the colorimetric reaction with diphenylcarbazide In a fluctuation test using E coli WP2 uvrA, NTA was not mutagenic, but it significantly increased the mutagenicity of potassium dichromate besides that of lead chromate Conversely, as assessed by mea
17 citations
TL;DR: An insoluble Cr(VI) compound, lead chromate (PbCrO4), was not cytotoxic nor mutagenic on V79 cells, probably because it is taken up by the cells very slowly, whereas the presence of NTA elicited a direct cytotoxicity and mutagenicity, which was dose-dependent from 5 X 10(-5) M to 10(-4) M PbCr O4.
14 citations
TL;DR: In this paper, it was shown that p-chloroaniline has a lethal effect on the embryos of Xenopus laevis at a concentration of 100 ppm and is development inhibiting at concentrations of 1 and 10 ppm, respectively.
14 citations
TL;DR: The enhancing effect of nickel chloride on the mutagenicity of UV or Cr(VI) is interpreted by an interference of Ni(II) with the repair of DNA lesions as well as the combined action of Cr and Ni produced a mutation rate 2.8 fold above that corresponding to the sum of the individual rates of these agents.
Abstract: 1. The HGPRT (Hypoxanthine‐Guanine‐Phospho‐Ribosyl‐Transferase) assay with Chinese Hamster V79 cells was used to measure the mutagenic effects of UV irradiation, potassium dichromate and nickel chloride. The agents were tested separately and in the combinations of UV plus nickel and dichromate plus nickel. 2. UV, Cr(VI) and Ni(II) were confirmed to be mutagenic in the V79 cell assay. The combination of UV(5J/m2) and Ni(II) (0.5 mM) caused a mutation rate 11.2 times above that corresponding to the sum of the individual mutation rates of these agents. The combined action of Cr(VI) (0.1 mM) and Ni(II) (0.5 mM) produced a mutation rate 2.8 fold above that corresponding to the sum of the individual rates of the separate agents. 3. The enhancing effect of nickel chloride on the mutagenicity of UV or Cr(VI) is interpreted by an interference of Ni(II) with the repair of DNA lesions.
11 citations
Patent•
13 Feb 1987
TL;DR: In this paper, a process for the manufacture of pigments by thorough homogenization of the chromate components with the pigments, and to the use of the Pigments in primers for ferrous and non-ferrous metallic substrates was described.
Abstract: The invention relates to corrosion-inhibiting pigments containing metallic oxides, phosphates and/or molybdates, wherein the metals are zinc, aluminum, iron, barium, strontium, calcium, magnesium and titanium, singly or in combination, wherein the pigments also contain 0.03-2% by weight of soluble sodium dichromate or equivalent amounts of potassium dichromate, ammonium dichromate or equivalent amounts of respective chromates or chromic acid, singly or in their mixture. The invention also relates to a process for the manufacture of the pigments by thorough homogenization of the chromate components with the pigments, and to the use of the pigments in primers for ferrous and non-ferrous metallic substrates.
8 citations
TL;DR: A spectrophotometric method based on the oxidation of aspirin by potassium dichromate in 5 M sulphuric acid is proposed, which is simple, highly accurate and readily applied to the determination of aspirin in pharmaceutical products.
Abstract: A spectrophotometric method for the determination of aspirin in the range 0–360 µg ml–1 is proposed. The method is based on the oxidation of aspirin by potassium dichromate in 5 M sulphuric acid at 80 °C (reaction time 30 min). The chromium(III) developed is measured at 580 nm. The method is simple, highly accurate and readily applied to the determination of aspirin in pharmaceutical products. The results were statistically compared with those obtained by the official BP method.
7 citations
TL;DR: In this paper, the absorption spectra of solutions of potassium chromate and dichromate in 100% sulfuric acid and dilute oleum have been investigated by cryoscopic and conductimetric methods.
Abstract: Solutions of potassium chromate and potassium dichromate in 100% sulfuric acid and dilute oleum have been investigated by cryoscopic and conductimetric methods. It is shown that they both react to give the compound CrO2(HSO4)2. The absorption spectra of solutions of potassium chromate and dichromate in 100% sulfuric acid are very similar to the spectra of species of the type CrO2X2. Potassium permanganate dissolves in 100% sulfuric acid to give green solutions which are shown to contain MnO3•SO4H. The formation of this compound has been further confirmed by conductimetric measurements in dilute oleum. The absorption spectra of these green solutions are also consistent with the formation of a species of the type MnO3X.
6 citations
Patent•
07 May 1987
TL;DR: The addition of an oxidizing agent remarkably improves the gallium extraction as discussed by the authors, which was shown to significantly improve the performance of gallium extractions in aluminum smelting dust leaching.
Abstract: Aluminum smelting dust is leached with mineral acids such as sulfuric acid, hydrochloric acid and nitric acid. Oxidizing agents such as potassium permanganate, manganese dioxide, hydrogen peroxide, ozone, potassium chromate, potassium dichromate, ammonium persulfate, sodium hypochlorite, sodium chlorite and sodium chlorate are added to the leach solution. The addition of an oxidizing agent remarkably improves the gallium extraction.
TL;DR: In this article, a radiometric method based on the redox substoichiometry has been developed for the determination of tellurium, and the chemical yield of the chemical content of 50 to 160 μg could be determined with an accuracy of ± 1.3% by means of the comparison method.
Abstract: A radiometric method based on the redox substoichiometry has been developed for the determination of tellurium. The oxidation of tellurium(IV) to tellurium(VI) with potassium dichromate was employed as the substoichiometric reaction, followed by TBP (tributyl phosphate) extraction of the unreacted tellurium(IV) as the substoichiometric isolation. The oxidation of tellurium(IV) with dichromate under the substoichiometric conditions was incomplete. The chemical yield of tellurium(VI) produced by the oxidation of tellurium(IV) with dichromate was 83%. It was found that a tellurium content of 50 to 160 μg could be determined with an accuracy of ±1.3% by means of the comparison method.
TL;DR: Further investigations were performed to decide which component of the welding-fume particles contributes most to such tolerance, and it was desirable to investigate nickel, as this did not appear to produce consistent effects.
Abstract: Earlier experiments have demonstrated that cutaneous hypersensitivity evoked by components from stainless steel welding fumes, such as chromium or nickel, may be inhibited by treatment with these haptens, given by intratracheal, intrapulmonary or oral administration prior to the sensitization procedure (Hicks and Caldas 1985). The inhibitory effects were interpreted as manifestations of tolerance. Further investigations were performed to decide which component of the welding-fume particles contributes most to such tolerance. These properties have previously been tested using potassium dichromate. However, the form of chromium in stainless steel metal fumes is predominantly as the chromate, which interacts with protein by a tanning-like process differing from that of dichromate. It was therefore desirable to verify that chromate could also induce tolerance. It was desirable also to investigate nickel, as this did not appear to produce consistent effects.
TL;DR: When ursolic acid was oxidized with potassium dichromate in the presence of sulfuric acid in glacial acetic acid, two new compounds were obtained in this paper.
Abstract: When ursolic acid was oxidized with potassium dichromate in the presence of sulfuric acid in glacial acetic acid, two new compounds were obtained. On the basis of the results of instrumental methods of analysis, structures have been suggested which correspond to 2-carboxy-5-hydroxy-11-oxo-3-oxaursa-1,12-dien-28-oic acid and 9-hydroxyl-11-oxo-2,3-secours-12-en-2,3,28-trioic acid 2,9-lactone.