Simultaneous titrimetric determination of bismuth ion and free nitric acid concentrations

1980 ◽  
Vol 52 (6) ◽  
pp. 940-942 ◽  
Author(s):  
David E. Hughes ◽  
Mario J. Cardone
Keyword(s):  
Nitric Acid ◽  
Free Nitric Acid ◽  
Titrimetric Determination

A novel method for the determination of uranium and free acidity in nuclear fuel process samples by extraction spectrophotometry

2019 ◽  
Vol 107 (4) ◽  
pp. 327-337
Author(s):  
Raghbendra Thakur ◽  
Pranab K. Tarafder ◽  
Raj Ranjan Jha
Keyword(s):  
Nitric Acid ◽  
Nuclear Fuel ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Anionic Complex ◽  
Free Acidity ◽  
Free Nitric Acid ◽  
Relative Standard ◽  
Yellowish Orange

Abstract A novel and useful extraction spectrophotometric method for the rapid determination of uranium and free acidity in nuclear fuel process samples using the reagent, 2,3-dihydroxynaphthalene as an extractant as well as color forming agent is described. Uranium at milligram level forms a yellowish- orange anionic complex with the ligand, 2,3-dihydroxynaphthalene over a pH range, 10–12. This anionic complex is easily extracted into ethylacetate as an ion-pair complex with cetyltrimethylammonium cation (CTA+). The absorbance of the ion-pair complex in ethylacetate is measured at 390 nm. The molar absorptivity and Sandell’s sensitivity of the system being 5.0×103 L·mol−1 cm−1 and 0.047 μg cm−2, respectively at 390 nm. This very reagent (2,3-dihydroxynaphthalene) also forms a yellowish-orange nitro product with free nitric acid (HNO3) in the presence of concentrated sulfuric acid. This nitro- product is easily extracted into the same solvent (ethylacetate) and absorbs maximum at 380 nm. The molar absorptivity (ε) and Sandell’s sensitivity of the system being 2.4×103 L·mol−1 cm−1 and 0.027 μg cm−2, respectively. By using the single chromophoric agent (2,3-dihydroxynaphthalene), both uranium and free acidity can be easily and reliably determined separately in the process solution. The relative standard deviations (RSD) are in the range, 0.5–2.0% and 1.5–2.0%, respectively for uranium and free nitric acid determinations. The method has been applied to nuclear fuel process solutions, and the results obtained have been found to be favorably comparable with those obtained from standard methods.

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.

Sign in / Sign up

Export Citation Format

Share Document