Improved extraction of acid-insoluble monosulfide minerals by stannous chloride reduction and its application to the separation of mono- and disulfide minerals in the presence of ferric iron

2021 ◽  
Vol 785 ◽  
pp. 147367
Author(s):  
Han Ye ◽  
Kun Gao ◽  
Guining Lu ◽  
Yingying Xie ◽  
John R. Reinfelder ◽  
...  
1939 ◽  
Vol 17b (6) ◽  
pp. 178-191 ◽  
Author(s):  
G. R. Smith ◽  
W. J. Dyer ◽  
C. L. Wrenshall ◽  
W. A. De Long

A study of factors affecting the ceruleomolybdate reaction for phosphate is reported. The concentrations of stannous and stannic ions, the presence of extraneous salts, and temperature are important factors affecting the intensity and stability of the blue colour.The stannous chloride reagent should be preserved from oxidation by storing it under hydrogen.The interference by ferric iron is due largely to its reaction with the reducing agent, and may be avoided by diluting the sample to contain 0.1 p.p.m. of phosphorus and using two or three times the usual quantity of stannous chloride.


1954 ◽  
Vol 26 (1) ◽  
pp. 159-168
Author(s):  
Armi Kaila

The interference of ferric and ferrous iron in the determination of phosphate by the molybdenum blue method has been studied. It was found that the presence of ferric iron in the solutions could cause either an increase or a decrease in the colour intensity depending on the amount of stannous chloride applied and on the acid and molybdate concentrations in the reagent. Also the phosphorus concentration exerted its effect upon the course of the errors. If the original modification of Truog and Meyer was employed, generally, the most convenient way for the elimination of the interference of ferric iron was to dilute the solution. An increase in the amount of stannous chloride largely helped to prevent the fading effect of ferric iron, provided the phosphorus concentration was not lower than 0.25 ppm. When the effect of ferric iron upon the development of molybdenum blue at various concentrations of sulphuric acid and ammonium molybdate was studied, the observation was made that at each acidity there could be found a concentration of molybdate in which the effect of even fairly high amounts of ferric iron was almost negligible. In lower molybdate concentrations the presence of ferric iron caused an increase in the colour intensity, in higher molybdate concentrations the fading effect of ferric iron was marked. This most suitable level of the molybdate concentration depended to a certain degree on the phosphorus concentration of the solution and on the amount of stannous chloride applied. Fairly good results could be obtained, if the ratio of molybdate (expressed as mg/ml) to acid (expressed as normality) in the solution to be reduced was five times as high as the acidity of the solution to be reduced (expressed as its normality), e.g. 4 in 0.8 N acid, 3.5 in 0.7 N acid, 3 in 0.6 N acid etc. Although it seemed to be fairly possible to avoid the interference of ferric iron by a proper choice of the concentrations of acid and molybdate and of the amount of stannous chloride applied, the fading effect of ferrous iron could not be prevented, if only sulphuric acid was used in the reagents. But the substitution of sulphuric acid by hydrochloric acid totally prevented the fading effect of ferrous iron. On the contrary, a slight increase in the colour intensity was demonstrated. This was true also when only one half of the acid present was hydrochloric acid. It was found that this mixture of sulphuric acid and hydrochloric acid in the molybdate reagent offers an available way for the elimination of the disturbing effect of iron.


1950 ◽  
Vol 22 (2) ◽  
pp. 361-362 ◽  
Author(s):  
Zolton. Szabo ◽  
Edith. Sugar

2020 ◽  
Vol 16 (8) ◽  
pp. 1161-1165
Author(s):  
Bashetti Nagaraju ◽  
Jagarlapudi V. Shanmukhakumar ◽  
Nareshvarma Seelam ◽  
Tondepu Subbaiah ◽  
Bethanamudi Prasanna

Background: Recently, there has been a lot of scientific interest in exploring the syntheses of oxygen and nitrogen-containing heterocyclic compounds due to their pharmacological activities. In addition, benzisoxazoles play a very important role in organic synthesis as key intermediates. Objective: In this paper, we focused on developing a novel synthetic route for biologically active arylisoxazoles under normal conditions, and simplified it to get high purities and yields, and also reported their anti-inflammatory activities. Method: An efficient and simple method has been explored for the synthesis of novel 3-methyl arylisoxazoles from o-nitroaryl halides via o-ethoxyvinylnitroaryls, using dihydrated stannous chloride (SnCl2.2H2O) in MeOH / EtOAc (1:1) via Domino rearrangement in one pot synthesis. Result: We synthesized novel 3-methylarylisoxazoles from o-nitroarylhalides via o-ethoxyvinylnitroaryls, using dihydrated stannous chloride (SnCl2.2H2O) in MeOH / EtOAc (1:1) via domino rearrangement. In this reduction, nitro group and ethoxy vinyl group change to the functional acyl ketones, followed by hetero cyclization. Here, the reaction proceeds without the isolation of intermediates like 2-acylnitroarenes and 2- acylanilines. All the synthesized compounds were completely characterized by the NMR and mass spectra. The compounds were also explored for their anti-inflammatory activity by carrageenan-induced inflammation in the albino rats (150-200 g) of either sex used in this entire study with the use of Diclofenac sodium as the standard drug. The initial evaluations identified leading targets with good to moderate anti-inflammatory activity. Conclusion: A simple, one-pot and convenient method has been explored for the synthesis of novel 3- methylarylisoxazoles with high purity and reaction yields. All the compounds 3a, 3c, 3d, 3f, 3g and 3h exhibited 51-64% anti-inflammatory activities.


2020 ◽  
Author(s):  
Isaac L. Hinz ◽  
◽  
Christine Nims ◽  
Christine Nims ◽  
Samantha Theuer ◽  
...  
Keyword(s):  

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yong Guo ◽  
Tomo Aoyagi ◽  
Tomoyuki Hori

Abstract Background Halotolerant Fe (III) oxide reducers affiliated in the family Desulfuromonadaceae are ubiquitous and drive the carbon, nitrogen, sulfur and metal cycles in marine subsurface sediment. Due to their possible application in bioremediation and bioelectrochemical engineering, some of phylogenetically close Desulfuromonas spp. strains have been isolated through enrichment with crystalline Fe (III) oxide and anode. The strains isolated using electron acceptors with distinct redox potentials may have different abilities, for instance, of extracellular electron transport, surface recognition and colonization. The objective of this study was to identify the different genomic signatures between the crystalline Fe (III) oxide-stimulated strain AOP6 and the anode-stimulated strains WTL and DDH964 by comparative genome analysis. Results The AOP6 genome possessed the flagellar biosynthesis gene cluster, as well as diverse and abundant genes involved in chemotaxis sensory systems and c-type cytochromes capable of reduction of electron acceptors with low redox potentials. The WTL and DDH964 genomes lacked the flagellar biosynthesis cluster and exhibited a massive expansion of transposable gene elements that might mediate genome rearrangement, while they were deficient in some of the chemotaxis and cytochrome genes and included the genes for oxygen resistance. Conclusions Our results revealed the genomic signatures distinctive for the ferric iron oxide- and anode-stimulated Desulfuromonas spp. strains. These findings highlighted the different metabolic abilities, such as extracellular electron transfer and environmental stress resistance, of these phylogenetically close bacterial strains, casting light on genome evolution of the subsurface Fe (III) oxide reducers.


Sign in / Sign up

Export Citation Format

Share Document