Topic
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.
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TL;DR: According to the series of cases presented here there is no doubt that agricultural workers are more often affected than others by actinomycosis, and an occupational hazard is indicated.
Abstract: in 1890 claimed that he had isolated an aerobic actinomycete from cases of the disease in cattle ; later workers showed that he almost certainly was dealing with a nonpathogenic organism. Infections due to aerobic actinomycetes are known, but in most cases of actinomycpsis the micro-aerophilic or anaerobic A. israeli can be isolated. This latter organism has never been found free in nature. In addition to its isolation from lesions of the disease it has been obtained by numerous workers from the mouths, carious teeth, gums, and crypts of the tonsils of healthy individuals (Lord, 1933; Emmons, 1936; Slack, 1942). The oral cavity is considered to be the normal h'abitat of this organism. When certain abnormal conditions arise in the mouth A. israeli is thought to alter its hiabit'from a saprophytic to a parasitic state and invade the tissues, giving rise to' actinomycosis. It would appear that trauma-for example, the extraction of a tooth-is one factor in precipitating this infection. That there must be others is apparent. The fact that pieces of grain or grass were often found in actinomycotic lesions was thought to support the theory of Bostroem that the causal organism was aerobic and came from the soil. It is now believed that such foreign bodies act only in their traumatic capacity and allow the A. israeli, already in the mouth, to gain access to the tissues. According to the series of cases presented here there is no doubt that agricultural workers are more often affected than others by actinomycosis. Previous surveys amply support this finding. There is no obvious explanation for this, but an occupational hazard is indicated. The city dweller is not immune from the disease, and it may well be that during a visit to the country or while working in his garden he is exposed to some factor which predisposes to this infection.
18 citations
Journal Article•
TL;DR: In this paper, a rapid method for the determination of organic carbon in marine sediments by potassium dichromate oxidation-ferrous sulphate titrimetry was developed, which can greatly shorten the experimental procedure and reduce the cost.
Abstract: A rapid method for the determination of organic carbon in marine sediments by potassium dichromate oxidation-ferrous sulphate titrimetry was developed.Some important analytical parameters,such as sample grain size,drying temperature and time,were optimized.The dosage of catalyst as well as the interference from Cl-and the interference elimination were also discussed.This method,derived from the National Standard(GB/T 17378.5—1998) and modified reasonably,can greatly shorten the experimental procedure and reduce the cost.The accuracy and reliability of this method have been proved by analysis of National Standard Reference samples and comparison with other analytical methods.
18 citations
TL;DR: In this article, the authors described extraction of chromium(VI) through supported liquid membrane (SLM), Celgard 2400, which was impregnated with trioctylphosphine oxide (TOPO) dissolved in toluene.
Abstract: The present study describes extraction of chromium(VI) through supported liquid membrane (SLM), Celgard 2400, which was impregnated with trioctylphosphine oxide (TOPO) dissolved in toluene. The stripping phase was comprised of diphenylcarbazide (DPC) in sulfuric acid (H2SO4) whereas the feed phase consists of potassium dichromate (K2Cr2O7) and hydrogen peroxide (H2O2). The effects of concentrations of chromium, TOPO, DPC, and H2SO4 have been studied in order to evaluate the transport efficiency of chromium(VI) ion. The optimum experimental conditions for the chromium(VI) extraction were established as follows: 19.2 × 10−4 mol L-1 chromium ion, 1.5 mol L-1 H2O2 concentration in the feed phase, 0.1 mol L-1 TOPO concentration in the membrane phase and 0.001 mol L-1 DPC and 1.5 mol L-1 H2SO4 as stripping phase. The measurements of percent recovery, distribution coefficient, flux and permeability were made at the given optimized conditions. The extraction time and membrane stability were also investigated. Extraction efficiency of 80% was recorded in 180 min and the SLM system was found stable up to 10 days. The optimized SLM system was then applied on the paint industry wastewater; about 80% of chromium(VI) was successfully removed from the wastewater.
18 citations
TL;DR: The method was used to determine trace oxalic acid in tea, spinach and urine samples with satisfactory results and the apparent activation energy of the catalytic reaction is 12.44 kJ/mol.
18 citations
TL;DR: The SOS Chromotest on Escherichia coli strain PQ37 was used to detect DNA damage induced by 16 chemical compounds and urine samples from smokers and a non-smoking psoriatic patient treated with mineral coal tar, and found it poorly sensitive to the mutagens present in urine from tobacco smokers.
Abstract: The SOS Chromotest on Escherichia coli strain PQ37 was used to detect DNA damage induced by 16 chemical compounds and urine samples from smokers and a non-smoking psoriatic patient treated with mineral coal tar. The results confirmed the strong SOS inducing activity of 2-aminoanthracene and benzo[a]pyrene with metabolic activation and N-methyl-N'-nitro-N-nitrosoguanidine, mitomycin C and 4-nitroquinoline-N-oxide without metabolic activation. A weaker response in the absence of microsomal enzymes was observed with hydroxyurea (only at high doses) and the soluble Cr(VI) compounds potassium chromate and potassium dichromate. No effect was observed with ampicillin, cadmium chloride, cyclophosphamide, griseofulvin, the insoluble Cr(VI) compound lead chromate, the soluble Cr(III) compounds chromium nitrate, chromium chloride, chromium potassium sulphate, and the chelating agent sodium nitrilotriacetate. Among the Cr(III) compounds only chromium acetate produced a low but significant increase of SOS inducing activity. Solubilization by nitrilotriacetate of genotoxic Cr(VI) from insoluble lead chromate was observed, whereas no interaction occurred between nitrilotriacetate and the soluble Cr(VI) and Cr(III) compounds. Using urinary XAD-2 extracts, we found the SOS Chromotest poorly sensitive to the mutagens present in urine from tobacco smokers which, on the other hand, were detected by the gene mutation assay in Salmonella typhimurium (Ames test). A urine sample obtained from a psoriatic patient, therapeutically treated with mineral coal tar, had a significant SOS inducing activity with and even without metabolic activation, whereas in the Ames test it was active only in the presence of metabolic activation.(ABSTRACT TRUNCATED AT 250 WORDS)
18 citations