Showing papers on "Sodium dichromate published in 1989"
TL;DR: Dichromate/arsenate and dichromate-arsenate-Cu2+ caused a marked decrease in mean fetal weight and an increased incidence of fetal resorption and abnormality formation.
35 citations
TL;DR: Evidence indicates that highly soluble hexavalent chromium compounds are also carcinogenic, while research by EPA to address the issue of valence state and solubility with respect to carcinogenicity is currently being conducted.
25 citations
TL;DR: Parenchymal lung tissue is more capable than bronchial tissue to detoxify reactive intermediates of xenobiotics, possibly explaining the greater susceptibility of bronchi to cigarette smoke-induced cancers.
Abstract: The pulmonary metabolism of xenobiotics was investigated by measuring the glutathione content and the activity of the aryl hydrocarbon hydroxylase, epoxide hydrolase, glutathione S- transferase, and uridine 5′-diphosphoglucuronosyl transferase enzymes in S-12 fractions of bronchial tree and peripheral lung parenchyma obtained at surgery from 21 patients. In parallel, the same preparations were used to assess either the activation of promutagens, i.e., benzo(a)pyrene, 2-aminofluorene, cyclophosphamide, and a cigarette smoke condensate, to metabolites reverting his Salmonella typhymurium strains, or the decrease of direct-acting mutagens, i.e., sodium dichromate, 4-nitroquinoline N-oxide, epichlorohydrin, and ICR 191. As compared to bronchus preparations, parenchymal preparations contained considerably higher concentrations of reduced glutathione, had a significantly higher epoxide hydrolase activity, and, as assessed by means of a quantitative index, were more efficient in activating 2-aminofluorene and in...
18 citations
Patent•
24 Apr 1989TL;DR: A process for the production of sodium dichromate comprising reacting sodium chromate with acids, the acids being sulfuric acid and NaHSO 4 formed as a waste product in the production process of CrO 3 and thus being contaminated with chromium compounds was described in this paper.
Abstract: A process for the production of sodium dichromate comprising reacting sodium chromate with acids, the acids being sulfuric acid and NaHSO 4 formed as a waste product in the production of CrO 3 and thus being contaminated with chromium compounds, adding PO 4 ions in excess to the NaHSO 4 contaminated with chromium compounds and precipitating the Cr(III) present therein as CrPO 4 at a temperature of 50° to 100° C. and at a pH value of 3 to 6.
3 citations
Patent•
15 Aug 1989TL;DR: In this paper, a process for the production of chromic acid CrO3, of high purity on the basis of the electrochemical principle, is described, and the measures to be taken comprising the process steps are: 1. preparation and purification of an aqueous sodium chromate/sodium dichromate solution, 2. conversion of said chromate and sodium dichrome solution into a sodium dichrome/chromic acid solution by evaporation, 3. separation of the crystallised chromic acids from the mother liquor, 4. recirculation of
Abstract: The present invention relates to a process for the production of chromic acid CrO3, of high purity on the basis of the electrochemical principle, the measures to be taken comprising the process steps:… 1. preparation and purification of an aqueous sodium chromate/sodium dichromate solution,… 2. conversion of said sodium chromate/sodium dichromate solution into a sodium dichromate/chromic acid solution,… 3. crystallisation of chromic acid from said sodium chromate/chromic acid solution by evaporation,… 4. separation of the crystallised chromic acid from the mother liquor,… 5. recirculation of the separated mother liquor in the centrifuge.
3 citations
Patent•
11 Apr 1989
TL;DR: Sodium hydroxide-water solutions that have freezing-melting point plateaus below 46° F can be used to store cooling capacity by their heat of fusion, and compositions that freeze at about 41° F are suitable as mentioned in this paper.
Abstract: Sodium hydroxide-water solutions that have freezing-melting point plateaus below 46° F. can be used to store cooling capacity by their heat of fusion, and compositions that freeze at about 41° F. are suitable, particularly when nucleating agents such as sodium dichromate and dispersing agents such as a clay, are also used.
2 citations
Patent•
29 Nov 1989
TL;DR: Sodium dichromate is prepared by reaction of sodium chromate with acids, in which, in addition to sulphuric acid, NaHSO4, which is formed as a waste product during CrO3 preparation, is additionally used as acid and in which an excess of PO4 ions is added to the NaSO4 contaminated with chromium compounds and the Cr(III) contained therein is precipitated as CrPO4 at temperatures of 50 to 100 DEG C and pH values of 3 to 6 as mentioned in this paper.
Abstract: Sodium dichromate is prepared by reaction of sodium chromate with acids, in which, in addition to sulphuric acid, NaHSO4, which is formed as a waste product during CrO3 preparation, is additionally used as acid and in which an excess of PO4 ions is added to the NaHSO4 contaminated with chromium compounds and the Cr(III) contained therein is precipitated as CrPO4 at temperatures of 50 to 100 DEG C and pH values of 3 to 6.
Patent•
24 Apr 1989TL;DR: Sodium dichromate is prepared by reaction of sodium chromate with acids, in which, in addition to sulphuric acid, NaHSO4 which is formed as a waste product during CrO3 preparation, is additionally used as acid and in which an excess of PO4 ions is added to the NaHS O4 contaminated with chromium compounds and the Cr(III) contained therein is precipitated as CrPO4 at temperatures of 50 to 100 DEG C and pH values of 3 to 6 as discussed by the authors.
Abstract: Sodium dichromate is prepared by reaction of sodium chromate with acids, in which, in addition to sulphuric acid, NaHSO4, which is formed as a waste product during CrO3 preparation, is additionally used as acid and in which an excess of PO4 ions is added to the NaHSO4 contaminated with chromium compounds and the Cr(III) contained therein is precipitated as CrPO4 at temperatures of 50 to 100 DEG C and pH values of 3 to 6.