Showing papers on "Potassium dichromate published in 2001"
TL;DR: Of all the compounds tested in this work, trimethyltin chloride was, by far, the most toxic and synergistic, and also found to be synergistic was the interactive effect of trimethyeltin chloride with cadmium and chromium applied together.
99 citations
TL;DR: The results suggest a handling effect in fish manipulated compared to those not manipulated, thus demonstrating the importance of including parallel negative controls in experimental design.
Abstract: Hexavalent chromium (Cr [VI]) genotoxicity was studied using fish micronucleus analysis in peripheral blood erythrocytes from Pimephales promelas, the fathead minnow. Forty-five- to 60-d-old fish were used to assess the spontaneous level of genotoxic damage. The genotoxic effect of Cr (VI) obtained from potassium dichromate (K2Cr2O7) in tests performed for 7-, 14-, and 21-d exposure periods was estimated. Significant micronucleated erythrocyte (MNE) induction was detected in fish exposed for 7 d to 2.5 mg/L of Cr (VI), and induction decreased after 21 d of exposure. The results suggest a handling effect in fish manipulated compared to those not manipulated, thus demonstrating the importance of including parallel negative controls in experimental design. Basal levels of MNE are reported, providing laboratory values for future assay quality control. The importance of determining the period with the highest expression of the genotoxic effects in this assay system was also confirmed.
89 citations
TL;DR: Changes in ETS activity and lipid and glycogen contents may be related to the activation of the respiratory chain due to an increase in energy cost associated with homeostatic phenomena, such as detoxification processes.
Abstract: Short-term (24 h) effects of four stressors (hypoxia, hyperoxia, potassium dichromate, fenitrothion) on the activity of the electron transport system (ETS) and total lipid, glycogen and protein contents were assessed in 4th instar larvae of Chironomus riparius. Hypoxia and hyperoxia caused an increase in ETS activity and protein content. Glycogen content decreased when larvae were placed under hypoxic conditions. ETS activity increased following exposure to 2 microg x l(-1) of fenitrothion. It decreased in larvae exposed to 20 microg x l(-1) of this insecticide. A decrease in lipid and glycogen contents was observed in larvae exposed to potassium dichromate or fenitrothion. Changes in ETS activity and lipid and glycogen contents may be related to the activation of the respiratory chain due to an increase in energy cost associated with homeostatic phenomena, such as detoxification processes. These results suggest that some parameters related to energy metabolism, such as ETS activity and lipid and glycogen contents, may be used as biomarkers of environmental disturbance in Chironomus riparius larvae.
71 citations
TL;DR: The physiologically based model is applicable to both single-dose oral studies and chronic oral exposure, and adequately reproduced the time dependence of blood plasma concentrations and rates of urinary chromium excretion in one of the subjects who, in a separate experiment, ingested daily 4 mg of an inorganic Cr(VI) salt.
66 citations
TL;DR: It is concluded that the DTPA‐cream clearly abrogates positive patch test reactions in nickel‐, cobalt‐ and copper‐sensitized subjects and that it may therefore be helpful in the management of allergic contact dermatitis.
Abstract: Chelating agents in protective barrier creams have often been used in the prevention of allergic contact dermatitis to nickel. In a pilot study, we demonstrated the preventive effect of 10% diethylenetriaminepentaacetic acid (DTPA) in an oil-in-water emulsion in nickel-sensitized patients. Now we reproduced these results in a randomized, double-blind study. Additionally, we investigated the efficacy of the barrier cream in other clinically relevant metal allergies. Individuals sensitized to various metals had a significant decrease in positive patch test reactions after pre-treatment with the DTPA-cream: 2.5% nickel sulfate (24/28 positive without pre-treatment versus 1/28 with pre-treatment; p<0.0001), 5% nickel sulfate (30/32 versus 15/32; p=0.0003), 1% cobalt chloride (19/20 versus 6/20; p=0.001) and 5% copper sulfate (13/14 versus 5/14; p=0.02). However, the cream had no protective effect with 1% palladium chloride (17/23 versus 16/23) and with 0.5% potassium dichromate (9/13 versus 7/13). We conclude that the DTPA-cream clearly abrogates positive patch test reactions in nickel-, cobalt- and copper-sensitized subjects and that it may therefore be helpful in the management of allergic contact dermatitis.
53 citations
TL;DR: The study reveals that comet assay is a sensitive and rapid method for detecting DNA damage caused by heavy metals such as chromium (Cr) and shows clear dose-dependent increases and decreases in higher doses.
44 citations
TL;DR: In this article, the structural properties of polyfluoroanilines were also compared using ammonium peroxydisulfate as oxidizing agent, and the change in the paramagnetic behavior was monitored by electron spin resonance spectroscopy.
36 citations
TL;DR: A spectrophotometric procedure for the determination of phenothiazines in pure form and in a number of their pharmaceutical preparations has been developed that offers the advantages of simplicity, accuracy, precision and sensitivity over many other methods.
Abstract: A spectrophotometric procedure for the determination of phenothiazines in pure form and in a number of their pharmaceutical preparations has been developed that offers the advantages of simplicity, accuracy, precision and sensitivity over many other methods. The method is based on the oxidation of phenothiazines by a known excess amount of potassium dichromate followed by the estimation of unreacted amount of dichromate by reacting with excess of iron(II) and measuring the iron(III) formed by complexing with thiocyanate. The reacted oxidant corresponds to the drug content. Different variables affecting the reaction between drugs and dichromate were studied and optimized. At the maximum absorption of 480 nm, Beer's law is obeyed in the range 2.5-29.75 microg/ml. The molar absorptivity and Sandell sensitivity of the procedure were calculated in addition to detection limit. Statistical treatment of the experimental results indicates that the procedure is precise and accurate. Excipients used as additives in pharmaceutical formulations did not interfere in the proposed procedure. The reliability of the method was established by parallel determination against the official BP methods. The procedure described was successfully applied to the determination of the bulk drugs and in pharmaceutical formulations.
29 citations
TL;DR: The D. melanogaster wing spot test was revealed to be a good assay, not only for evaluating genotoxic activity but also for detecting antigenotoxic effects in vivo.
Abstract: The genotoxic activity of three selenium compounds (sodium selenite, sodium selenate, and selenious acid) and the antigenotoxic effects of sodium selenite in combination with the chromium compound potassium dichromate were studied using the wing spot test of Drosophila melanogaster. This assay is based on the principle that the loss of heterozygosity of suitable recessive markers, multiple wing hairs (mwh) and flare-3 (flr3), can lead to the formation of mutant clones of larval cells, which are then expressed as spots on the wings of the adult flies. Pretreatment and chronic cotreatment was comparatively used for the antigenotoxicity study. From the results obtained, it was evident that all selenium compounds are unable to increase the frequency of any of the three categories of spots recorded (small, large, and twin spots). Nevertheless, the antigenotoxic effects of sodium selenite were clearly demonstrated, in both cotreatment and pretreatment, by a complete suppression of those clones induced by potassium dichromate. Therefore, the D. melanogaster wing spot test was revealed to be a good assay, not only for evaluating genotoxic activity but also for detecting antigenotoxic effects in vivo. Environ. Mol. Mutagen. 37:70–75, 2001 © 2001 Wiley-Liss, Inc.
22 citations
TL;DR: P-aminohippuric acid uptake impairment and glutamine synthetase activity loss caused by the highest doses of hexachloro-1:3-butadiene and potassium dichromate suggests that high doses of segment-specific chemicals may involve other portions of the proximal tubule; in addition, the decrease of glutamine synthetic activity caused by potassium dichrome may be related to the protein content loss.
19 citations
Patent•
08 Nov 2001TL;DR: In this paper, the sporulation, sterilization and storage of coccidial oocyst which are characterized by an absence of the highly toxic chemical potassium dichromate was discussed.
Abstract: Methods are provided for the sporulation, sterilization and storage of coccidial oocyst which are characterized by an absence of the highly toxic chemical potassium dichromate. Also provided are compositions containing sporulated oocysts which are free of potassium dichromate.
TL;DR: In this paper, the results for the temperature dependence of the photobleaching reactions of Fluorescein and Rose Bengal dissolved in poly(vinyl alcohol) in the presence of diethylenetriamine, potassium dichromate and 2-aminoethanethiol hydrochloride were presented.
Abstract: This work presents the results for the temperature dependence of the photobleaching reactions of Fluorescein and Rose Bengal dissolved in poly(vinyl alcohol) in the presence of diethylenetriamine, potassium dichromate and 2-aminoethanethiol hydrochloride. These samples were subjected to a continuous irradiation with a 150 W mercury high pressure arc lamp at a wavelength coincident with the maximum of the dye absorption. The photobleaching processes were described by a double exponential and a mono-exponential function for Fluorescein and Rose Bengal, respectively. Apparent activation energies were calculated using the Arrhenius plots and these values were strongly affected by the presence of additives. Different additives are employed in the studies of the photobleaching reactions of Fluorescein and Rose Bengal in poly(vinyl alcohol) matrices: (a) diethylenetriamine is a quencher of all excited states; (b) potassium dichromate is an electron acceptor complexed with the polymer chains and inhibited the photobleaching; (c) 2-aminoethanethiol hydrochloride is an efficient quencher of the triplet state. The role of these additives upon the photoreaction is discussed.
TL;DR: In this paper, the utility of potassium dichromate in the presence of Lewis acids under solid phase conditions is described, and the reagent efficiently oxidizes alcohols, acyloins, oximes and semicarbazones to their corresponding carbonyl compounds, while trimethylsilyl and tetrahydropyranyl ethers, ethylene acetals and ketals undergo oxidative deprotection.
Abstract: The synthetic utility of potassium dichromate in the presence of Lewis acids under solid phase conditions is described. This reagent efficiently oxidizes alcohols, acyloins, oximes and semicarbazones to their corresponding carbonyl compounds, while trimethylsilyl and tetrahydropyranyl ethers, ethylene acetals and ketals undergo oxidative deprotection to produce carbonyl compounds efficiently.
TL;DR: Myricetin appears to be less effective in inducing oxidative DNA damage in rat hepatocytes in culture when compared with the previously published studies on isolated rat liver nuclei.
Abstract: Myricetin was selected as a model polyphenolic flavonoid for study of its pro-oxidant activity in rat hepatocytes in culture. Its activity was compared with that of a known oxidant, potassium dichromate. Cytotoxicity, membrane lipid peroxidation, and DNA strand breaks were used as endpoints of oxidative cell injury. Myricetin, like potassium dichromate, induced a concentration-dependent increase in cytotoxicity and membrane lipid peroxidation concurrent with a decrease in double-stranded DNA content in cultured rat hepatocytes. However, myricetin was a less potent oxidant than dichromate. Myricetin appears to be less effective in inducing oxidative DNA damage in rat hepatocytes in culture when compared with our previously published studies on isolated rat liver nuclei.
TL;DR: A highly synchronous reproducibility of results can be achieved by using a well-standardized patch-test system, especially with nickel sulfate, however, distinct allergens and test systems need to be evaluated separately.
Abstract: commercially available, highly standardized, ready-to-use test withnickel sulfate andpotassiumdichromate patchtests attached synchronously to both sides of the back of patients with a history system (TRUE-testâ ) with randomized location of the allergens. Using a double-blind study design 589 patients with a of nickel allergy, conducted with a highly standardized randomized test system (TRUE-testâ ). Out of 589 patients tested, a history of nickel allergy were tested with 2 of the most common standard allergens that have a diŒerent potential to elicit total of 388 had responded with allergic reactions to nickel sulfate and 130 to potassium dichromate. The reproducibility of allergic, questionable and irritant reactions, i.e. nickel sulfate and potassium dichromate. positive nickel (dichromate) patch tests was 99.2% (90.8%). The reaction index was also calculated, which relates the number of allergic reactions obtained with a test preparation to the number MATERIAL AND METHODS of questionable and irritant reactions; the reaction index can range from ‐1 (questionable and irritant reactions only occur) Thirteen centres of the German Contact Dermatitis Research Group contributed data from a double-blind study approved by the local to 1 (allergic reactions only occur). For nickel sulfate the Ethical Committees. Patch-test patients older than 17 years with a reaction index was 0.91, but it was only 0.23 for potassium history of nickel allergy (reported eczematous reactions to skin contact dichromate, as a result of considerably more questionable reac- with metal likely to contain nickel or positive nickel patch test) were tions. In conclusion, a highly synchronous reproducibility of enrolled after giving their informed consent. Exclusion criteria were results can be achieved by using a well-standardized patch-test as follows: any kind of immunosuppressive medication, treatment of the back with ultraviolet (UV) light or corticosteroids within 4 weeks system, especially withnickel sulfate. However, distinct allergens prior to testing, ineammatory dermatoses of the back, any major
01 Jan 2001
TL;DR: Skin prick tests elicited an immediate wheal reaction with both nickel sulfate and potassium dichromate at a concentration of 10 mg/mL, whereas skin test results with common aeroallergens were negative.
Abstract: Skin prick tests elicited an immediate wheal reaction (4 × 4 mm) with both nickel sulfate and potassium dichromate at a concentration of 10 mg/mL, whereas skin test results with common aeroallergens were negative. Results of patch tests with nickel sulfate and potassium dichromate were negative. Skin prick test results with these metallic salts were negative in 5 atopic patients. SIC tests were performed according to the tidal breathing method7 through use of a De Vilbiss model 646 nebulizer (Somerset, Pa). SIC with NiSO4 at 5 mg/mL induced a dual asthmatic response (the maximum fall in FEV1 from baseline during the early asthmatic response was 23%). A dual asthmatic response was also obtained with potassium dichromate at 25 mg/mL (the maximum fall in FEV1 during the early response was 49%). The methacholine inhalation test was repeated 24 hours after SIC; nickel sulfate and potassium dichromate yielded PC20 values of 0.15 and 0.098 mg/mL, respectively. The result of a bronchial challenge test with potassium dichromate at 25 mg/mL in an asthmatic control subject was negative. Specific IgE to nickel and chromium salts was determined by direct ELISA and allergenic cross-reactivity by ELISA inhibitions. NiSO4 and CrK(SO4)2 were conjugated with human serum albumin (HSA) at a metal-HSA ratio of 1:10 by weight and dialyzed against distilled water at pH 7.6 Positive ELISA results of 0.460 and 0.911 optical densities (ODs) were obtained against NiSO4-HSA and
Patent•
24 Oct 2001
TL;DR: The building waterproofing liquid is used in building construction to dilute mortar so as to level surface of building and to resist seepage as discussed by the authors, it consists of octodecyl fatty acid, sodium bicarbonate, potassium hydroxide, sodium fluoride, ammonia water, water and potassium dichromate.
Abstract: The building waterproofing liquid is used in building construction to dilute mortar so as to level surface of building and to resist seepage. It consists of octodecyl fatty acid, sodium bicarbonate, potassium hydroxide, sodium fluoride, ammonia water, water and potassium dichromate. It can chock miniature capillary channels formed in solidified mortar and serves as waterproofing and anti-seepage agent. Compared with avaiable similar products, the present invention has low construction cost, reduced labor strength and no environmental pollution.
Journal Article•
TL;DR: In this article, the authors discuss the interference of hydrogen perokide on COD measurement in Fenton system by potassium dichromate method and the auther put forwand by predetermining H2O2 concentration in water sample and then deducting of it to eliminate interference of H 2O in COD calculation.
Abstract: ：Discussing the interference of hydrogen perokide on COD measurement in Fenton system by potassium dichromate method， the auther put forwand by predetermining H2O2 concentration in water sample and then deducting of it to eliminate the interference of H2O in COD calculation．
TL;DR: Thiola at the concentrations of 20 and 50 mg kg-1b.wt.
Abstract: The genotoxic effect of hexavalent potassium dichromate (K2Cr2O7) was investigated in mice in vivo using sister chromatid exchange (SCE) and chromosomal aberration analysis. K2Cr2O7 induced a significant increase in the frequency of SCE's after intraperitoneal (i.p.) treatment with the doses 6, 12, 24 mg kg-1b.wt. which correspond to 1/8, 1/4 and 1/2 of the experimental LD50. The lowest tested dose 3 mg kg-1b.wt. had no effect with respect to SCE's and its effect reached 6.57 ± 0.36/cell compared with 5.80± 0.55/cell for the control. The frequency of SCE's reached 9.03 ±0.20 after treatment with the highest tested dose of K2Cr2O7, a value which is less than that induced by mitomycin C (13.10 ± 0.40) as the positive control. Thiola at the concentrations of 20 and 50 mg kg-1b.wt. had moderate but non-significant effect for minimizing the frequency of SCE's induced by different doses of K2Cr2O7.With respect to chromosomal aberrations, all the tested concentrations of K2Cr2O7 (3, 6, 12, 24 mg kg-1b.wt.) induced a significant increase in the percentage of chromosomal aberrations in mouse bone marrow as well as in mouse spermatocytes 24 h after single i.p. treatment. The incidence of chromosomal damage increased significantly with increasing the dose. However mitomycin C induced higher effect. The results also show that the pretreatment with thiola at the dose of 50 mg kg-1b.wt. significantly reduced the percentage of chromosomal aberrations induced by K2Cr2O7 in all the treatment groups and the results confirm the protective role of thiola which has been proved previously against the genotoxicity of some mutagens.
Patent•
01 Dec 2001
TL;DR: In this paper, the authors describe a double-watt nozzle, facilitating reaction on the surface being treated to give it a mirror-type finish, and demonstrate the use of the double nozzle for implementing the process.
Abstract: The silverplating of non-porous curved surfaces comprises separate injection of a compound containing silver nitrate and of a compound containing glucose. Also claimed is apparatus for implementing the process. The apparatus has a double nozzle, facilitating reaction on the surface being treated to give it a mirror-type finish. The first compound also contains caustic soda, ammonia, potassium dichromate and distilled water, and the second compound contains glucose, formaldehyde, distilled water, sodium sulfate, potassium nitrate and sulfuric acid.
Patent•
05 Jan 2001
TL;DR: In this article, a method for measuring chemical oxygen demand by potassium dichromate at a low cost with a high reliability is provided to improve the reliability of measured data within allowable upper and lower limit values when measuring water pollution degree.
Abstract: PURPOSE: A method for measuring COD(Chemical Oxygen Demand) by potassium dichromate at a low cost with a high reliability is provided to improve the reliability of measured data within allowable upper and lower limit values when measuring water pollution degree. CONSTITUTION: A method for measuring COD(Chemical Oxygen Demand) by potassium dichromate at a low cost with a high reliability includes the steps of adding a sample and a mercuric sulfate in a flask, adding a silver sulfate solution, a potassium dichromate solution, and a silver sulfate solution in the flask and connecting the flask to a cooling tube to heat after stirring, adding a ferro-phosphor indicator after cooling the flask and dropping a ferrous sulfate ammonium solution, and carrying a test with distilled water in the same manner, wherein the amounts of the sample and the reagents used for the measuring are reduced by a same ratio, 0.3-0.7times of the amount used in the EPA(Environmental Protection Agency) law.
Patent•
15 Sep 2001
TL;DR: In this article, a method for measuring amount of soil organic material by using a color difference meter is provided to measure a reaction end point by using the color difference meters, and to conveniently measure the amount of the soil organic materials in a short time.
Abstract: PURPOSE: A method for measuring amount of soil organic material by using a color difference meter is provided to measure a reaction end point by using the color difference meter, and to conveniently measure the amount of the soil organic material in a short time. CONSTITUTION: A dichromate potash and sulfate are produced for analyzing soil organic material. Then, a reference curve of an organic material amount is generated. Herein, 0.625-7.50g of glucose is molten in purified water of 100ml for adding 2ml of dichromate potash and 3ml of the sulfate. After adding 20ml of the purified water, 0.56-6.72% of organic material is added. Color of the solution is measured by using a color difference meter for generating the reference curve. Herein, a reference organic material amount is arranged on a Y-axis, and measured value by the color difference meter is arranged on an X-axis. Then, soil organic material is measured. Herein, 0.2-0.5g of sample soil is added to the dichromate potash, the sulfate, and the purified water to measure a color by using the color difference meter. Then, the measured value is inputted to the reference curve for calculating amount of the soil organic material.
15 Apr 2001
TL;DR: InChIKey as discussed by the authors is a mild oxidizing reagent capable of oxidizing several functional groups; 2, 3 releases alcohols from allyl and propargyl silyl ethers4 and carbonyl compounds from acetals4.
Abstract: [93250-25-0] Ce2CrN6O22 (MW 768.26)
InChI = 1S/2Ce.Cr.6NO3.4O/c;;;6*2-1(3)4;;;;/q2*+4;;6*-1;;;2*-1
InChIKey = DJVSELAWYHJAIC-UHFFFAOYSA-N
(mild oxidizing reagent capable of oxidizing several functional groups;2, 3 releases alcohols from allyl and propargyl silyl ethers4 and carbonyl compounds from acetals4)
Alternate Name: BTNCC.
Solubility: sol DMSO, DMF; moderately sol H2O; sparingly sol EtOH, MeCN; insol PhH.
Form Supplied in: yellow-orange solid.
Preparative Method: to a solution of Potassium Dichromate (0.02 mol) in H2O (100 mL), Cerium(IV) Ammonium Nitrate (0.02 mol) in H2O (50 mL) is added, and the mixture diluted with H2O (150 mL). The resulting precipitates are filtered, triturated with acetone, separated, and dried in air (70%).
Handling, Storage, and Precautions: stable at elevated temperatures (>200 °C) and to storage at rt for months. Chromate is a cancer suspect agent. Work with this reagent should be conducted in a fume hood.
15 Apr 2001
TL;DR: InChI as discussed by the authors is a mild oxidizing reagent for the transformation of several functional groups in dry benzene, which is a cancer suspect agent and inhalation of this reagent should be avoided.
Abstract: [92989-80-5] H4CeCrN2O12 (MW 416.18)
InChI = 1S/Ce.Cr.2NO3.2H2O.4O/c;;2*2-1(3)4;;;;;;/h;;;;2*1H2;;;;/q+4;;2*-1;;;;;2*-1
InChIKey = PMFGJFYLWKSTSM-UHFFFAOYSA-N
(mild oxidizing reagent for the transformation of several functional groups in dry benzene2)
Alternate Name: DCCD.
Solubility: sol DMF, DMSO; moderately sol H2O; insol MeCN, EtOH, PhH.
Form Supplied in: orange-red solid; readily available.
Preparative Method: to a hot solution of Potassium Dichromate (0.1 mol) a solution of Cerium(IV) Ammonium Nitrate (0.1 mol) is added. After cooling, the precipitate is washed with H2O and acetone and dried in the air (79%).2
Handling, Storage, and Precautions: stable >220 °C, and at rt for months. Chromium is a cancer suspect agent and inhalation of this reagent should be avoided.
15 Apr 2001
TL;DR: The TBADC (mild selective oxidizing agent for benzylic and allylic alcohols) as mentioned in this paper can oxidize carbon-halogen bonds and can be removed by filtration (62.8 g, 90% yield).
Abstract: [56660-19-6] C32H72Cr2N2O7 (MW 700.92)
InChI = 1S/2C16H36N.2Cr.7O/c2*1-5-9-13-17(14-10-6-2,15-11-7-3)16-12-8-4;;;;;;;;;/h2*5-16H2,1-4H3;;;;;;;;;/q2*+1;;;;;;;;2*-1
InChIKey = MMKQSIQNDMIVIN-UHFFFAOYSA-N
(mild selective oxidizing agent for benzylic and allylic alcohols;2 can oxidize carbon–halogen bonds3)
Alternate Name: TBADC.
Physical Data: mp 139–143 °C.
Solubility: sol dichloromethane, chloroform.
Form Supplied in: orange crystalline solid; widely available.
Preparative Method: a concentrated aqueous solution (300 mL) of Potassium Dichromate (29.4 g, 0.1 mol) is added to a saturated aqueous solution (300 mL) of Tetra-n-butylammonium Bromide (64.4 g, 0.2 mol). TBADC precipitates and can be removed by filtration (62.8 g, 90% yield).
Handling, Storage, and Precautions: reported to be a toxic agent. The reagent should be handled in a fume hood.