scholarly journals Influence of Nitric Acid and Hydrochloric Acid on the Calcium Determination by AAS in the Presence of Interference Inhibitor

2013 ◽  
Vol 62 (8) ◽  
pp. 701-705
Author(s):  
Muga YAGUCHI ◽  
Katsuro ANAZAWA
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Calcium Determination

Extraction of iron, cobalt, nickel and copper with dibenzyl sulfoxide solution in toluene

1979 ◽  
Vol 44 (7) ◽  
pp. 2024-2031 ◽  
Author(s):  
František Vláčil ◽  
Huynh Dang Khanh
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Distribution Ratio ◽  
Separation Factor ◽  
Chromatographic Separation ◽  
The Other ◽  
Iron Cobalt ◽  
Cobalt Nickel ◽  
Factor Α

The dependence of the distribution ratio of the metal on the concentration of hydrochloric of nitric acid was examined for Fe, Co, Ni and Cu extraction with 0.05M solution of dibenzylsulfoxide in toluene. Iron is extracted considerably more than the other metals, and is better extracted from hydrochloric acid than from nitric acid. The separation factor αFe/M (for 8M-HCl) is of the order of 104; this is not sufficient for a separation of trace quantities of iron from Co, Ni and Cu, but even at lower concentrations of HCl (e.g., 5M) the values is high enough for extraction chromatographic separation. The composition of the iron solvate extracted from HCl or LiCl medium was determined to be HFeCl4.2 B (B = dibenzyl sulfoxide).

DETERMINATION OF TRACE AMOUNTS OF SILVER IN GALENA ORES

1960 ◽  
Vol 38 (9) ◽  
pp. 1488-1494 ◽  
Author(s):  
E. J. Bounsall ◽  
W. A. E. McBryde
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Silver Content ◽  
Aqueous Sodium Chloride Solution ◽  
Aqueous Sodium

An analytical method is described for the determination of microgram amounts of silver in galena ores, based on the "reversion" of silver dithizonate. Silver is separated from relatively large amounts of lead by extraction as dithizonate into chloroform from an aqueous 1:99 nitric acid solution. Separation from mercury, which is also extracted under these conditions and would, if present, interfere in the analysis, is achieved by reverting the dithizonate solution with a 5% aqueous sodium chloride solution which is also 0.015 molar in hydrochloric acid. Following dilution of this aqueous solution and adjustment of pH, silver is again extracted into chloroform as the dithizonate, and determined absorptiometrically. Analyses of a number of galena ore samples showed a precision of within 3% for a silver content ranging from 0.03 to 0.4%.Some other methods for isolating silver from these samples, which were tried but found unsatisfactory, are discussed.

scholarly journals An improvement of calcium determination technique in the shell of molluscs

2009 ◽  
Vol 52 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Cristiane Soído ◽  
Maurício Carvalho Vasconcellos ◽  
Antônia Gonçalves Diniz ◽  
Jairo Pinheiro
Keyword(s):  
Hydrogen Peroxide ◽  
Nitric Acid ◽  
Experimental Model ◽  
Calcium Content ◽  
Conventional Technique ◽  
Organic Substances ◽  
Complexometric Method ◽  
Wet Weight ◽  
Calcium Determination

The complexometric method is usually applied to quantitative calcium determination in different materials; however the application of this method to calcium determination in molluscs shells infers significant interferences to the results. The snail Bradybaena similaris, a terrestrial gastropod, was used as experimental model to the improvement of this method. The shells were calcinated and dissolved in nitric acid, the hydrogen peroxide was also used to clarify the medium after the acid addition. The calcination procedure and the use of nitric acid reduced the significantly the interferences, allowing a major degree of destruction of the organic substances of the shell. The improvement of the calcium determination technique usually employed showed calcium content of 874.24 ± 56.617 mg of CaCO3/g of ash in comparison to the conventional technique that allowed the determination of 607.79 ± 67.751 mg of CaCO3/g of shell, wet weight.

scholarly journals Micro-crystalline structure of platinum

1902 ◽  
Vol 69 (451-458) ◽  
pp. 433-435
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Crystalline Structure ◽  
Aqua Regia ◽  
Pure Platinum ◽  
Small Ingot

The crystalline structure of platinum does not appear to have been studied, although it forms an interesting subject for investigation. A small ingot of pure platinum was obtained for the experiments. A section was cut therefrom and machined to 5/16 inch square and 1/10 inch in thickness. The section was then carefully polished and etched in aqua regia of the following strength :— 4 parts of hydrochloric acid (sp. gr. 1·2). 1 part of nitric acid (sp. gr. 1·42).

New reaction for free hydrochloric acid

1906 ◽  
Vol 6 (1) ◽  
pp. 58-58
Author(s):  
F. Simon
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Gastric Juice ◽  
Free Hydrochloric Acid ◽  
Blue Coloration

For the discovery of free hydrochloric acid in gastric juice, Dr. Simon proposes a new reaction based on the properties of guaiac gum to oxidize in the presence of various oxidants (for example, nitric acid) and give a characteristic blue coloration.

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