Showing papers on "Potassium dichromate published in 2018"

The systemic toxicity of heavy metal mixtures in rats

Abstract: To explore the health effects of multi-heavy metal exposure, Sprague Dawley (SD) rats were orally given one dose of heavy metal mixtures (HMMs). The eight most common detectable heavy metals in Ningbo area are zinc (Zn), copper (Cu), manganese (Mn), chromium (Cr), nickel (Ni), cadmium (Cd), lead (Pb) and mercury (Hg). In this study, mixtures of these eight heavy metals were prepared using the compounds zinc sulfate heptahydrate, cupric sulfate, manganese dichloride, potassium dichromate, nickel dichloride, cadmium dichloride, lead acetate, and methyl mercury chloride with ion mass proportions of 1070.0, 312.6, 173.1, 82.6, 30.0, 13.3, 6.6, and 1.0, respectively. The rats were randomly divided into four groups. Beside the control group, each rat received a corresponding dose of HMMs 215, 464 or 1000 mg per kg body weight (bwt), respectively. The rats were observed for 4 weeks. During the last week of observation, the Morris water maze test was used to investigate spatial learning and memory in the treated rats. The rats were exsanguinated under complete chloral hydrate anesthesia and organ coefficients were measured. Biochemical tests of blood and serum samples were carried out. The results showed abnormalities in the hematological system, decreased renal function, hepatic injury and disturbances in the electrolyte balance of the rats treated with a high dose of HMMs. Death of some rats was also observed. This paper analyzed how a one-time high dose oral administration of HMMs induced systemic toxicity.

Chromium (VI) – induced stress response in the plant Plantago ovata Forsk in vitro

Abstract: Plants experience severe physiological stress from heavy metal pollution caused by improper discarding of the industrial wastes. Hexavalent chromium [Cr (VI)] is one of the major heavy metal pollutants in India and is present particularly in some regions where Plantago ovata grows to a great extent. This study was aimed at finding the effects of Cr (VI) on P. ovata and manoeuvres of the plant to combat such heavy metal exposure in vitro. Potassium dichromate was used as a source of Cr (VI) to induce the heavy metal stress. Range of Cr (VI) sublethal doses [0 mM (control), 0.1 mM, 0.3 mM, 0.5 mM, 1 mM, 1.5 mM and1.8 mM] was used to observe its effect on the plant. The seeds of the plant were grown on sucrose-agar media with different concentrations of potassium dichromate, and ten-day old seedlings were then harvested and examined. The germination rate reduced below 50% at 1.9 mM Cr (VI) concentration and thus, 0 mM–1.8 mM concentration ranges were found to be suitable for sublethal dose. Morphological changes namely, reduction of the shoot-root length and multiple root development were caused by Cr (VI) in a dose-dependent manner. The plant showed elevated responses against Cr (VI), up to 1.5 mM (10 days treated) in terms of increasing accumulation of secondary metabolites like polyphenols, chlorophyll content (chlorophyll a, b and total chlorophyll), carotenoids and total antioxidant activity. DPPH radical scavenging activity along with malondialdehyde (MDA) content was not significantly elevated with the increase in Cr (VI) concentration indicating that the lipid peroxidation rate within the tissue was low. Phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) gene expressions were upregulated by 1 mM Cr (VI) concentration, which decreased at higher concentrations. The atomic absorption spectroscopy analysis also showed significant accumulation of Cr (VI) in the shoot and root with an increase in the potassium dichromate concentration. Cr (VI) reduced the shoot-root length and seed germination in a dose-dependent manner. The plant system tried to combat the Cr (VI) stress by upregulating the stress response genes in the phenylpropanoid pathway along with an increase in polyphenol and antioxidant contents, which were evident from the lowering of lipid peroxidation rate and increase in PAL and PPO gene expressions.

Oxidative-extractive desulfurization of liquid fuel using stannous chloride-acetic acid mixture as catalyst

Abstract: Present study reports catalytic oxidative-extractive desulfurization (COEDS) of model oil (dibenzothiophene (DBT) dissolved in iso-octane) using an acid mixture (composed of Lewis acid and organic acid (glacial acetic acid)) as catalyst and inorganic oxysalt, potassium dichromate, as oxidant. A series of acid mixtures were prepared by mixing different amount of Lewis acids (SnCl2, CaCl2 or CuCl2) in specific amount of acetic acid and tested for the removal of sulfur from model oil. SnCl2, which performed best as a Lewis acid, was used in further studies. Effect of Lewis acid to sulfur (molar) ratio was studied in the range of 1–5. Effects of other parameters i.e. oxidant to sulfur (O/S) molar ratio, temperature and time on desulfurization efficiency were also investigated. Fourier transform infrared (FTIR) spectroscopy of SnCl2-CH3COOH mixture, model oil (before COEDS), raffinate and extract layers was carried out to understand the removal mechanism. Apparent activation energy for COEDS process wi...

Impact of chromium and boron compounds on the reproductive function in rats.

Abstract: The purpose of this research is to study the process of mutagenesis and the reproductive function in male rats under separate and combined exposure to chromium and boron compounds. The experiment was conducted on two groups of animals. The first group was used to assess the ability of potassium dichromate and boric acid to induce mutation in germ and somatic cells under isolated and combined administration with the use of the dominant lethal mutations test and the micronuclei test in the polychromatophilic erythrocytes of the bone marrow. The second group was used to test the combined and separate effect of the compounds under consideration on the reproductive function of male rats during the spermatogenesis cycle. When used in specific doses, boron compounds are a promising means of preventing and correcting chromium-induced effects in chromium production facility workers and people who live in ecologically adverse regions.

The role of eugenol in the prevention of chromium-induced acute kidney injury in male albino rats

Abstract: Background Potassium dichromate induces nephrotoxicity mainly due to increased cellular oxidative stress. Objectives To evaluate the possible renoprotective effects of eugenol on the damage induced by potassium dichromate poisoning in male rats. Methods 30 male Wistar rats were divided into 3 groups, 10 rats in each group; Control group: given olive oil orally (5 mL/kg body weight) for 10 consecutive days. Potassium dichromate (PDC) group: received olive oil orally (5 mL/kg body weight) for 10 consecutive days, then a single s.c. injection of PDC (15 mg/kg) was given in the tenth day. And eugenol + PDC group: received eugenol orally (100 mg/kg body weight/day) for 10 consecutive days and a single s.c. injection of PDC (15 mg/kg) in the tenth day. Then the animals were anaesthetized, blood samples were taken from the abdominal aorta, for measurement of serum urea and creatinine, and lactate dehydrogenase (LDH). Also reduced glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD) and tumor necrosis factor alpha (TNF-α) were monitored in renal tissue. Results PDC caused significant increase in serum urea, creatinine and LDH levels; this was accompanied with significant decrease in renal GSH and SOD contents, and increase in renal MDA and TNF-α. Histopathological investigations provoked tubular necrosis associated with mononuclear cell infiltration. Pretreatment of rats with eugenol significantly change all previously mentioned PDC-induced effects. Conclusion The findings of the current study revealed that eugenol protected the kidney against PDC-induced acute kidney injury in rats by its antioxidant and anti-inflammatory properties.

Modified APHA closed-tube reflux colorimetric method for TOC determination in water and wastewater.

Abstract: The analysis of total organic carbon (TOC) by the American Public Health Association (APHA) closed-tube reflux colorimetric method requires potassium dichromate (K2Cr2O7), silver sulfate (AgSO4), and mercury (HgSO4) sulfate in addition to large volumes of both reagents and samples. The method relies on the release of oxygen from dichromate on heating which is consumed by carbon associated with organic compounds. The method risks environmental pollution by discharging large amounts of chromium (VI) and silver and mercury sulfates. The present method used potassium monochromate (K2CrO4) to generate the K2Cr2O7 on demand in the first phase. In addition, miniaturizing the procedure to semi microanalysis decreased the consumption of reagents and samples. In the second phase, mercury sulfate was eliminated as part of the digestion mixture through the introduction of sodium bismuthate (NaBiO3) for the removal of chlorides from the sample. The modified method, the potassium monochromate closed-tube colorimetry with sodium bismuthate chloride removal (KMCC-Bi), generates the potassium dichromate on demand and eliminates mercury sulfate. The semi microanalysis procedure leads to a 60% reduction in sample volume and ≈ 33.33 and 60% reduction in monochromate and silver sulfate consumption respectively. The LOD and LOQ were 10.17 and 33.90 mg L−1 for APHA, and 4.95 and 16.95 mg L−1 for KMCC-Bi. Recovery was between 83 to 98% APHA and 92 to 104% KMCC-Bi, while the RSD (%) ranged between 0.8 to 5.0% APHA and 0.00 to 0.62% KMCC-Bi. The method was applied for the UV-Vis spectrometry determination of COD in water and wastewater. Statistics was done by MINITAB 17 or MS Excel 2016.

Hydrogen Peroxide Interference in Chemical Oxygen Demand Assessments of Plasma Treated Wastewaters

Abstract: Plasma-liquid interaction generates hydrogen peroxide, ozone, and other reactive species along with ultraviolet radiation and short-lived highly reactive hydroxyl radicals, thus representing a novel advanced oxidation process for removal of recalcitrant organic compounds and overall chemical oxygen demand (COD). The COD test is ubiquitous in wastewater treatment as a measurement of the pollution potential of organic matter present in the waste stream; however, residual hydrogen peroxide from plasma treatment interferes with COD analysis by reducing the potassium dichromate oxidizing agent. The magnitude of this interference is investigated by dosing waters with hydrogen peroxide by chemical solution and by dielectric barrier discharge plasma jet, and then measuring the residual peroxide and COD of the samples. Corresponding samples are aerated to strip the hydrogen peroxide and the COD is assessed. Tests are performed with deionized water, as well as diluted solutions of methylene blue and ethylene glycol.

Metal Allergy: Chromium

Abstract: Allergic contact dermatitis to chromium (Cr) is one of the most common and most severe metal allergies. Chromium-sensitized persons need to strictly avoid contact with chromium, which is a difficult task due to its main sources being nonmetals and non-labeled occupational or everyday life products. Regulations, work hygiene, and the decrease of hexavalent chromium sources can be effective measures to reduce the prevalence of allergic contact dermatitis. There are no inexpensive and simple analytical tools available that can detect released chromium with sufficient sensitivity to detect potential sources that should be avoided. Hexavalent chromium has significantly higher skin and cell penetration rates compared with trivalent chromium. Hexavalent chromium is therefore generally considered the more potent allergen compared with trivalent chromium. Anionic trivalent chromium species have the highest skin penetration rates among trivalent chromium species. The chromium release chemistry from potential sources, the chromium oxidation state and chemical form, skin penetration, and skin reactions depend all largely on pH and the presence of complexing and reducing species. Therefore, some environments and sources, especially alkaline ones, should be particularly avoided. A trivalent chromium-protein conjugate is the recognized antigen by cutaneous dendritic cells. Patch testing with potassium dichromate is the main diagnostic tool, but causes a relatively high percentage of irritant or doubtful reactions. Hypersensitivity to chromium released from metallic implants is rarer compared with allergic contact dermatitis. Allergic asthma to chromium has been reported for a few occupations.

Histological study on the possible protective effect of curcumin on potassium dichromate induced hypothyroidism in adult male albino rats

Abstract: Introduction: Potassium dichromate, a widely used heavy metal in several industries induces hypofunction and tissue insult of the thyroid gland via oxidative stress. Curcumin; is a natural commonly used spice has a strong anti-inflammatory and antioxidant properties.Aim of the work: To investigate the possible protective effect of curcumin on the hypothyroidism induced by potassium dichromate in albino rats.Materials and Methods: Thirty- five adult male albino rats were divided into five groups, 15 rats in group I (control) and 5 rats in each of group II, III, IV and V. Group II (curcumin group) received curcumin orally (100 mg /kg/bw) daily for 4 weeks. Group III (potassium dichromate induced hypothyroidism) received i.p injection of potassium dichromate (2 mg/kg/bw) daily for 2 weeks. Group IV (recovery group) received potassium dichromate as group III then left untreated for another 2 weeks. Group V(curcumin and potassium dichromate group) received curcumin concomitant with potassium dichromate as in groups II and III, respectively daily for 2 weeks and only curcumin was continued for another 2 weeks. T3, T4 and TSH were assessed. Thyroid sections were subjected to toluidine blue, H&E, PAS and PCNA immunohistochemical stains. Morphometric and statistical studies were done.Results: Thyroid tissue insult and hypofunction with significantly decreased T3, T4 and increased TSH were detected in group III. Additionally, there was a significant increase in the mean values of follicular cell height, follicular diameter, mean number of PCNA positive nuclei and a significant decrease in the mean value of area percent of colloid versus group I, II and V with non-significant differences versus group IV. In group V, there was an obvious serological and histological improvement compared to group III and IV.Conclusion: Curcumin had protective effect against hypothyroidism and thyroid tissue damage induced by potassium dichromate.

Comparison of the Davies and Gray titrimetric method with potassium dichromate and ceric titrants

Abstract: The modified New Brunswick Laboratory (NBL) Davies and Gray titrimetry method uses potassium dichromate standard 136-f from the National Institute of Standards and Technology for calibration. However, the presence of chromium in the resulting waste stream makes the disposal of waste from this procedure costly. The Actinide Analytical Chemistry (C-AAC) group at Los Alamos National Laboratory investigated and transitioned to a cerium based titrant as an alternative. We present the first long-term analytical study using this ceric-based titration method and compare it with NBL results based on the more-widely used dichromate titrimetric method.

Potential action of Rumex vesicarius (L.) against potassium dichromate and gentamicin induced nephrotoxicity in experimental rats.

Abstract: To determine the ameliorative potential of the active fraction from different extracts of Rumex vesicarius against potassium dichromate and gentamicin induced nephrotoxicity in experimental rats and its possible mechanism of action. Both sex wistar rats were divided into 6 groups (n=6/group) were fed with a control, potassium dichromate and gentamicin supplemented with different extracts at the doses of 200 and 400mg/kg respectively. Oral administration of EERV offered a significant (p<0.01 and p<0.001) dose dependent protection against PD and GN induced nephrotoxicity. Potassium dichromate and gentamicin nephrotoxicity assessed in terms of body weight, kidney weight, creatinine, urea, uric acid, BUN, albumin and total protein. Thus the present study revealed that EERV phytochemical constituents play an important role in protection against kidney damage.

Oxidative stress responses of juvenile catfish, Clarias gariepinus exposed to potassium dichromate at sublethal concentrations in south-eastern Nigeria

Abstract: The oxidative stress responses of Clarias gariepinus exposed to potassium dichromate at sublethal concentrations for 28 days were studied in 2017. Fish were exposed to 0.165, 0.0825 and 0.033 mg l−...

Detailed Investigation into the Preparation of Graphene Oxide by Dichromate Oxidation

Abstract: Graphene oxide (GO) can be prepared using numerous protocols including the well‐known Hummers method that relies on potassium permanganate as the oxidizing agent. Given the widespread use of GO and its many applications, a better understanding of the mechanisms of chemical oxidation is highly desirable including research into alternative oxidizing agents. Limited work has so far been carried out into using potassium dichromate as an oxidizing agent and the chemical structure of GO prepared by dichromate oxidation remains unclear. Here we present a full structural characterization of GO prepared by dichromate oxidation and we investigate its thermal stability. Furthermore, the previously reported preparation protocol is optimized by reducing the reaction time from 5 days to 20 hours and showing that sodium nitrate is not needed in the reaction mixture. Contrary to previous reports, we show that the GO material produced by dichromate oxidation is highly oxidized if thermal annealing is avoided. Compared to traditional GO, larger amounts of carboxylic acid groups are found which constitutes a major advantage for chemical processing and applications in materials chemistry.

Preparation method of carbon-manganese dioxide composite material

Abstract: The invention provides a preparation method of a carbon-manganese dioxide composite material The preparation method is characterized by comprising the following specific steps: carrying out intercalation-expansion treatment on a raw material graphite to obtain graphene-like expanded graphite, wherein an intercalation agent is prepared from acid and an oxidant, the acid is one or more of sulfuricacid, phosphoric acid and nitric acid and the oxidant is one or more of potassium permanganate, potassium ferrate and potassium dichromate; an expansion agent is prepared from acid and an oxidant, theacid is one or two of the sulfuric acid and the phosphoric and the oxidant is one or more of hydrogen peroxide, ammonium persulfate, potassium persulfate and sodium persulfate; enabling the graphene-like expanded graphite and potassium permanganate to react under a shaking or standing condition; carrying out water washing to obtain the carbon-manganese dioxide composite material In the compositematerial, a conjugated structure of a carbon material keeps relatively good and manganese dioxide vertically grows on the surface of a carbon nano-sheet The carbon-manganese dioxide composite material prepared by the preparation method can be widely applied to fields including supercapacitors, lithium-ion batteries, fuel cells, energy conversion and the like

Reduction–Oxidation of Chromium Ions in Aqueous Solution by Treatment with Atmospheric-Pressure Direct-Current Discharge in Argon

Abstract: Kinetic features of the oxidation–reduction processes of chromium ions in a potassium dichromate aqueous solution subjected to treatment in argon atmospheric-pressure dc discharge have been investigated in the discharge current range of 20–80 mA and the dichromate concentration range of 0.1–0.5 mmol/L. The solution served as the discharge cathode. It has been revealed that the discharge treatment stimulates the reduction reactions of Cr6+ to Cr3+ ions and the reverse reactions of oxidation of Cr3+ to Cr6+ ions; i.e., the oxidation–reduction reactions are reversible. The limiting degree of reduction of Cr6+ ions has been found to depend on the discharge current and the initial concentration of the solution. The apparent rate constants of oxidation and reduction have been determined, and the energy efficiency of the process has been evaluated. The data are compared with the results obtained earlier for a discharge in air.

Method for detecting COD in sewage and reclaimed water

Abstract: The invention discloses a method for detecting COD in sewage and reclaimed water. The detection mechanism, the water sampling amount and the addition amount of oxidant of the invention are the same asthe method of HJ 828-2017. A precious metal silver reagent is replaced by 4 kinds of metal ion sulfates with different catalytic activities and selectivity such as manganese sulfate, copper sulfate,potassium aluminum sulfate. The oxidizing property of potassium dichromate is reduced by using the reduction of acidity of sulfur-phosphorus mixed acid, the adsorption of phosphoric acid, and the presence of chromium potassium sulfate, and a large volume closed digestion is used to shorten the digestion time to 25 min, thereby achieving mercury-free to prevent the interference of chloride ions. Atthe same time, the reaction pressure is increased, the digestion temperature is increased to 165 DEG C, so that the oxidation efficiency is improved. The digestion / titration bottle is integrated, amanual indicator titration is replaced by a gold composite electrode potentiometric titration, and the COD in the water sample is calculated. The 5 kinds of metal ion sulfates of the method for detecting the COD in sewage and reclaimed water are non-toxic, easily available and cheap; the sample of the sulfur-phosphorus mixed acid large volume closed digestion has a good adaptability, the COD results are consistent with the method of HJ 828-2017, and the rapid determination and green determination of the COD are achieved.

Effect of Potassium Dichromate on Ovary and Uterus in Female Mice

Abstract: The histopathological alterations in ovary and uterus were evaluated to investigate the possible effects ofhexavalent chromium as potassium dichromate (K2Cr2O7)in female albino mice.Forty-five adult female albino mice were used in this study.The mice treated orally with 500 and 1000 ppm of potassium dichromate that dissolved in tap water for 10, 20, and 30 days.The histologic examination by light microscope for the ovaries and uteri in potassium dichromate-treated mice revealed different histopathological alterations in these organs, whilst these organs of control groups exhibited a normal architecture. In addition, the results showed that the histological changes depend on the concentration and duration of exposure to potassium dichromate.

Synthesis and crystal structures of two new uranyl coordination compounds obtained in aqueous solutions of 1-butyl-2,3-dimethylimidazolium chloride

Abstract: Two new uranyl coordination compounds, [C9H17N2]3[(UO2)2(CrO4)2Cl2(H2O)2]Cl·5H2O (1) and (C9H17N2)[(UO2)(C2O4)Cl] (2), have been synthesized by adding potassium dichromate (K2Cr2O7) or oxal...

Method capable of accurately determining chromium content in drinking water

Abstract: The invention discloses a method capable of accurately determining the chromium content in drinking water. Acetone, sulfuric acid, phosphoric acid, a 20% urea solution, a 4% potassium permanganate solution, a 2% sodium nitrite solution and a 0.2% hydrogen hydroxide solution are selected for standby application, and zinc sulfate is weighed and dissolved in water to obtain a zinc sulfate solution; sodium hydroxide is weigh and dissolved in water to obtain a sodium hydroxide solution, and the zinc sulfate solution and the sodium hydroxide solution are mixed; dry potassium dichromate is weighed and dissolved with water to obtain a stock solution, and the stock solution is transferred to a 1000 mL volumetric flask, wherein per ml of the stock solution contains 0.100 micrograms of hexavalent chromium; 5.00mL of a chromium standard stock solution is absorbed in a 500mL volumetric flask, wherein per ml of the standard use solution contains 1.00 micrograms of hexavalent chromium; 0.2 g of diphenylcarbodiimide is weighed, dissolved in 50mL of acetone, diluted with water to 100mL, and used to reduce Cr6+ to Cr3+; at this time, the pH value of the water sample is adjusted to 8, a developer solution is added, the water sample is kept still for 5 mins and then acidified for developing, then a standard curve is obtained by using the same method; and a result is obtained by calculation. The method has a simple and convenient measurement process and high measurement accuracy and can prevent excessive chromium from harming the human body to protect people's health.

The Combined Effect of Shungite and Heavy Metals on the Growth of Microalgae Роpulation

Abstract: The combined effect of 3 mg/L potassium dichromate, 1.5 mg/L cadmium sulfate, and 100 g/L shungite on the growth of chlorococcales green microalgae culture Scenedesmus quadricauda (Turp.) Breb. is studied. The toxic effect of potassium dichromate and cadmium sulfate on S. quadricauda is estimated by calculating the share of living and dead cells and physiological parameters. The toxic effect of heavy metals does not manifest itself under the combined action of potassium dichromate or cadmium sulfate and shungite on S. quadricauda. The best growth of the algae culture occurred only when only shungite was added to the culture medium. Shungite can be used to neutralize the toxic effect of heavy metals.

X-ray micro-computed tomography of postmortem brain tissue using potassium dichromate as a contrast agent

Abstract: No abstract available.

Method for detecting content of total iron in composite lithium iron phosphate positive-electrode material

Abstract: The invention discloses a method for detecting the content of total iron in a composite lithium iron phosphate positive-electrode material. The method comprises the following steps: step 1, mixing a carbon composite lithium iron phosphate positive-electrode material with a hydrochloric acid solvent, successively carrying out heating and cooling to room temperature; step 2, adding a stannous chloride solution used as a reducing agent and a sodium tungstate solution used as an indicator into a solution obtained in step 1; and step 3, adding a mixed sulfuric acid-phosphoric acid solution into a solution obtained in the step 2, and with sodium diphenylaminesulfonate as an indicator, carrying out titration by using a standard potassium dichromate titration solution and calculating the mass fraction of total iron. According to the method in the invention, the sodium tungstate solution and the sodium diphenylaminesulfonate are used as indicators, so the indicators are simple to prepare, and no other irritating gas is generated during detection; and the detection method is simple and convenient, and detection results are more accurate.

Whey Protein and Nigella sativa Oil Mitigate Potassium Dichromate Induced Hepatic Injury, Oxidative Stress and Hematotoxicity in Rats

Abstract: The present study was carried out to evaluate the antioxidant property of whey protein and/or Nigella sativa Oil (NSO) against hepatotoxicity evoked by potassium dichromate (K 2 Cr 2 O 7 ). Designed for this purpose, we detected the 8 weeks challenge result of whey protein (100 and 200 mg/kg, p.o) with/or without Nigella sativa oil (5ml/kg, p.o) in contradiction of poisoned albino rats with one dose of potassium dichromate (30mg/Kg, I.P) at the end of challenge period. Concerning plasma level, whey protein with/or without Nigella sativa oil were ameliorated the potassium dichromate liver damage concerns, so it exhibited a major progress in Aspartate Aminotransferase (AST), Alanine Amino Transferase (ALT), Alkaline Phosphatase (ALP), and Gamma-Glutamyl Transferase (GGT). Moreover, whey protein or Nigella sativa oil reduce the deleterious effects of potassium dichromate on Triiodothyronine (T3), Thyroxine (T4), Thyroidstimulating Hormone (TSH), glucose and Complete Blood Count (CBC). In addition, they displayed an important improvement in hepatic antioxidant enzymes, Catalase (CAT) and Superoxide Dismutase (SOD) beside reduced Glutathione (GSH), and with a subsequent decrease in Malondialdehyde (MDA) or Nitric Oxide (NO) levels in comparison with the untreated K 2 Cr 2 O 7 group. Also, whey protein with/or without Nigella sativa oil improve the histopathological alterations produced by the potassium dichromate. These outcomes suggest that whey protein or Nigella sativa oil can be used as effective antioxidant aginst potassium dichromate intoxication as they modulate liver function and decrease oxidative stress.

Reagent for rapidly determining COD of high-chlorine wastewater and detection method

Abstract: The invention discloses a reagent for rapidly determining COD of high-chlorine wastewater and a detection method. The reagent comprises a digestion solution containing potassium dichromate, deionizedwater and concentrated sulfuric acid and a catalyst containing silver nitrate and concentrated sulfuric acid, wherein the digestion solution comprises, by mass, 1-2 parts of the potassium dichromate,20-30 parts of the deionized water and 10-20 parts of the concentrated sulfuric acid, and the catalyst comprises, by mass, 1-2 parts of the silver nitrate and 10-20 parts of the concentrated sulfuricacid. The reference potassium dichromate with constant weight is used in the acidic solution and reacts with a reducing substance in the wastewater under the action of the silver sulfate catalyst, anda COD value is obtained by ultraviolet spectroscopy colorimetry. Different mercury sulfate is added in different chloride radical ranges to avoid the distortion of the COD value caused by influence of the mercury sulfate on the color of the reagent, and a blank solution is used to adjust chloride radicals to avoid the distortion of the COD value caused by influence of the chloride radicals, thereby making the obtained COD value be true COD. Therefore, the reagent can rapidly and accurately solve the determination of the COD in a high chlorine state.

Method for determination of chemical oxygen demand in water

Abstract: The invention discloses a method for determination of chemical oxygen demand in water, wherein the method comprises the following steps: a, carrying out acidification treatment of a water sample withhydrochloric acid with the volume concentration of 1-10%, to obtain an acidified water sample; b, taking 20 [mu]L-2.5 mL of the acidified water sample and carrying out high temperature combustion at the temperature of 600-1200 DEG C, taking 20 [mu]L-2.5 mL of the acidified water sample and carrying out low temperature combustion at the temperature of 100-300 DEG C; c, determining the composition and content of gas generated in high temperature combustion and low temperature combustion respectively; and d, calculating the chemical oxygen demand. The method has simple test steps; the reagent amount is low, only needs 40 [mu]L-5 mL and is far lower than 50-120 mL in the traditional test method; and moreover, the test method is green and environmentally friendly and has no need of use of potassium dichromate, potassium permanganate, mercury sulfate, silver sulfate, concentrated sulfuric acid and other reagents which can produce secondary pollution.

Cuantificación de etanol en gasolina por microextracción líquido-líquido y valoración potenciométrica.

Abstract: A new and practical method is proposed for the determination of ethanol in gasoline. It is based on ultrasonic assisted liquid-liquid microextraction (LLME) with hexane-water and a redox back- titration, in which ethanol is oxidized with potassium dichromate in excess, and later the remaining dichromate is titrated with ferrous ammonium sulfate. Detection of the end point of the titration was by potentiometry with a redox electrode. To estimate the accuracy of the method, fuel samples were fortified with ethanol at different concentrations, obtaining and average recovery of 99 ± 6 %. The precision of the method expressed as a relative standard deviation in percentage was of 5 %. Thus, an accurate and precise analytical method was developed, a practical and easy to implement tool in any laboratory.

Chemical of the Week

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