Potassium dichromate

About: Potassium dichromate is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 18967 citations. The topic is also known as: Potassium dichromate(VI) & Chromium potassium oxide.

Hypersensitivity to dichromate among asymptomatic workers in a chromate pigment factory.

Abstract: Hypersensitivity to chromate, as well as nickel and cobalt, salts can present as bronchospasm (!) or acute asthma (2), in addition to allergic contact dermatitis or urticaria (1, 2). Not all sensitized persons are symptomatic, though they may become so on increased exposure (3). We attempted to determine the chromium sensitivity level, independent of clinical symptoms, among workers in a chromate pigment factory. This plant produces chromium yellow: lead sulfochromate, lead chromate, basic lead chromate (lead sulfochromate enriched with molybdenum). The workers are exposed to chromium salts by inhalation and by skin contact. The most heavily exposed persons are supposed to wear gloves and a face mask. The study was performed on 29 male volunteers in the factory, of various ages. No respiratory or dermatologic symptoms were observed prior to the tests. We applied the following patch tests recommended in the European standard series: potassium dichromate (0.5% pet.), cobalt chloride (I% pet.), nickel sulfate (5% pet.). Patch tests were applied on the back at the end of the working week (Friday afternoon), and removed after 48 h. A 1st reading was made then and a 2nd one 24 h later. 6 persons showed positive reactions to dichromate and 6 others to nickel. 3 of these 12 individuals

Hexavalent Chromium Induced Oxidative Stress and Toxicity on isolated human lymphocytes

Abstract: Introduction: The most toxic form of chromium (Cr) in the environment is the oxyanion chromate (Cr (VI)). In this form it is soluble and is transported into the cells. Chromate structurally resemble phosphate and sulfate, and can be transported into cells by the anion carrier. Methods and Results : In this study, toxicity effects of Cr (VI) on isolated human lymphocytes was studied using accelerated cytotoxicity mechanisms screening (ACMS) technique. Human lymphocytes were isolated from blood of healthy persons using Ficoll-paque PLUS standard method. The trypan blue dye was used to cytotoxicity assay. The mechanistic parameters including reactive oxygen species (ROS), lysosomal membrane destabilization, mitochondrial membrane potential (MMP) collapse, lipid peroxidation, GSH and GSSG levels were assessed after 1, 2 and 3 hrs in potassium dichromate treated lymphocytes. The results indicate that toxicity of Cr (VI) was concentration dependent in human lymphocytes. Cr (VI) significantly (p<0.05) induced ROS production, MMP reduction, lysosomal membrane destabilization and lipid peroxidation in human lymphocytes. There was also a decrease in intracellular GSH and raise in extracellular GSSG levels in Cr (VI) treated lymphocytes. Conclusion : OOur findings revealed that ROS formation with subsequent cellular damages is the molecular mechanism for Cr (VI) induced human blood lymphocyte toxicity. Keywords: Cytotoxicity; Chromium (VI); Human lymphocyte

6価クロムの細胞毒性に対する dl-ペニシラミンの拮抗作用

Abstract: The effects of various chelating agents on the cytotoxicity induced by hexavalent chromium, potassium dichromate, were examined. HeLa cells were incubated in Eagle's minimum essential medium (MEM) with or without the chromate alone, or both chromate and any one of DL-penicillamine, glutathione (reduced and oxidized form), L-cysteine, 2, 3-dimercapto-1-propanol (BAL) and ethylene-diaminetetra-acetic acid (2Na-EDTA and 2Na·Ca-EDTA). After a given period of incubation, cell growth and the amount of chromium in the cells were measured. The results obtained were as follows. 1) The growth of HeLa cells in MEM with 3.4 μM chromate at 3 days of incubation was approximately 15% of that of the control cells. The growth of HeLa cells in MEM containing 3.4 μM chromate and 670.2 μM DL-penicillamine was 96%. However, no remarkable antagonism against the chromate toxicity was induced by 0.3 to 325.4 μM reduced glutathione, 0.2 to 163.2 μM oxidized glutathione, 0.6 to 56.9 μM L-cysteine, 0.8 to 8.1 μM BAL, 0.3 to 268.6 μM 2Na-EDTA, 0.2 to 224.0 μM 2Na·Ca-EDTA. 2) DL-penicillamine could not restore the cell growth inhibited by a preincubation in MEM with 3.4 μM chromate for 6 or 24 hours. 3) The chromium content (as Cr) of HeLa cells in MEM with 3.4 μM chromate at 6 hours of incubation was 0.148 μg/106 cells. When 670.2 μM DL-penicillamine was added to MEM containing 3.4 μM chromate, the chromium content decreased to 0.0141μg/106 cells (70% reduction). Other chelating agents, 325.4 μM reduced glutathione, 569.3 μM L-cysteine and 805.2 μM BAL, also remarkably reduced the chromium content. However, 163.2 μM oxidized glutathione, 268.6 μM 2Na-EDTA and 224.0 μM 2Na·Ca-EDTA did not reduce the chromium content. These results suggest that DL-penicillamine might inhibit the chromium uptake by HeLa cells and thus prevent the chromium-induced cytotoxicity.

Solid state reaction between dichromates and oxalates

Abstract: The thermal investigation of the reaction taking place between dichromates and oxalates in the solid state has been done taking two systems of potassium dichromate-potassium oxalate and sodium dichromate-sodium oxalate. The techniques employed include thermogravimetry, differential thermal analysis, infrared spectroscopy and X-ray diffraction studies. The results indicate a stoichiometric reaction of dichromate and oxalate in 1∶1 ratio to give the corresponding chromate as the sole product.

Afterchrome dyeing of wool. Part B — characterisation of chromium‐treated wool by secondary particle mass spectrometry

Abstract: Secondary particle mass spectrometry has been used for the first time to determine the oxidation state and depth distribution of chromium on and in wool fibres. Wool tops were dyed with 4% o.w.f. CI Mordant Black 11 and aftertreated with 1% o.w.f. potassium dichromate, and wool samples treated in a blank dyebath aftertreated with 6% o.w.f. potassium dichromate were analysed. It could be shown that the absolute concentration of chromium in a surface layer 50 nm thick became enriched with chromium by a factor of two, compared with the bulk fibre. Chromium in the hexavalent oxidation state was found to be mainly present in the outermost part of the fibres, while trivalent chromium was dominant inside the fibres.