Colorimetric Determination of Moderate Concentration of Uranium in Perchloric Acid Solutions

1956 ◽  
Vol 28 (1) ◽  
pp. 45-47 ◽  
Author(s):  
Louis. Silverman ◽  
Lavada. Moudy
Keyword(s):  
Perchloric Acid ◽  
Colorimetric Determination ◽  
Acid Solutions

Small Amounts of Copper in Dyes and Rubber Chemicals. Colorimetric Determination with Zinc Dibenzyldithiocarbamate

1953 ◽  
Vol 26 (1) ◽  
pp. 257-262
Author(s):  
R. I. Martens ◽  
R. E. Githens
Keyword(s):  
Carbon Tetrachloride ◽  
Acid Solution ◽  
Specific Method ◽  
Colorimetric Determination ◽  
Acid Solutions ◽  
Metallic Ions ◽  
Reagent Solution ◽  
Cent Solution ◽  
Dyed Fabrics

Abstract This work was undertaken to provide a more specific method for the routine determination of small amounts of copper in rubber chemicals, dyes, and dyed fabrics. A dithiocarbamate type of reagent—a 0.01 per cent solution of zinc dibenzyldithiocarbamate in carbon tetrachloride—will selectively extract copper from acid solutions containing relatively large amounts of most other metals. The method is accurate and reproducible to about 0.5 microgram in the range of 0.5 to 40 micrograms of copper. No precipitations or filtrations are required. The reagent is commercially available, the reagent solution and the color of the extracted copper dibenzyldithiocarbamate are stable, and the acid solution remaining after extraction may be used to determine other metals. Because copper dibenzyldithiocarbamate is selectively extracted from solutions containing relatively large amounts of many other metallic ions, the reagent may be used to determine small amounts of copper in metals and their salts.

THE SEPARATION OF SMALL AMOUNTS OF THE PLATINUM METALS: 1. THE COLORIMETRIC DETERMINATION OF RHODIUM AND ITS SEPARATION FROM IRIDIUM

1961 ◽  
Vol 39 (12) ◽  
pp. 2389-2393 ◽  
Author(s):  
D. E. Ryan
Keyword(s):  
Hydrochloric Acid ◽  
Stannous Chloride ◽  
Colorimetric Determination ◽  
Acid Solutions ◽  
Platinum Metals ◽  
Hydrochloric Acid Solutions ◽  
Product Separation ◽  
Chromous Chloride ◽  
Made In

A method for separating small amounts of rhodium from iridium is described. In 3 to 9 M hydrochloric acid solutions, the amber-to-red complex of bivalent rhodium with 4,5-dimethyl-2-mercaptothiazole is formed after reduction of tervalent rhodium with chromous or stannous chloride. Rhodium is quantitatively separated from iridium by chloroform extraction of this product; separation can be made in solutions that have been fumed with sulphuric acid if chromous chloride is used for the prior reduction of the rhodium. The complex, after removal of the chloroform, is dissolved in dilute hydrochloric acid, and the optical density of the resulting colored solution is measured.

Determination of the activity of water in highly concentrated perchloric acid solutions

1969 ◽  
Vol 47 (12) ◽  
pp. 2326-2328 ◽  
Author(s):  
Henry Wai ◽  
Keith Yates
Keyword(s):  
Perchloric Acid ◽  
Isopiestic Method ◽  
Acid Solutions

The water activities of concentrated aqueous perchloric acids in the range 40–75% have been determined at 25 °C using a modified isopiestic method.

The ketonization of acetophenone enol in concentrated aqueous sulphuric and perchloric acid solutions. Implication on X acidity function correlations of the enolization reaction and determination of the keto–enol equilibrium constant as a function of acidity

1990 ◽  
Vol 68 (10) ◽  
pp. 1653-1656 ◽  
Author(s):  
Y. Chiang ◽  
A. J. Kresge ◽  
R. A. More O'ferrall ◽  
B. A. Murray ◽  
N. P. Schepp ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Key Words ◽  
Equilibrium Constant ◽  
Perchloric Acid ◽  
Acidity Function ◽  
Acid Solutions ◽  
Function Correlation ◽  
Aqueous Perchloric Acid ◽  
Sulfuric Acid Solutions

Rates of ketonization of the enol of acetophenone, generated by flash photolytic photohydration of phenylacetylene, were measured in aqueous sulfuric and perchloric acid solutions over the concentration range 1–50 wt.% acid; rates of enolization of acetophenone, monitored by bromine scavenging, were also measured in aqueous perchloric acid solutions over the same concentration range. The results suggest that the curvature observed in a previous X acidity function correlation of the rate of enolization in sulfuric acid solutions was an artifact produced by insufficiently efficient scavenging, and that introduction of the activity of water in the correlating expression, used previously to eliminate the curvature and believed to reflect covalent involvement of water in the enolization reaction, is unnecessary. The present results also show that the keto–enol equilibrium constant for acetophenone decreases with increasing acidity in these concentrated sulfuric and perchloric acid solutions. Key words: acetophenone, enolization, ketonization, keto–enol equilibrium, concentrated acid solutions.

A Method for the Colorimetric Determination of β-Glucuronidase in Urine, Serum, Tissue; Assay of Enzymatic Activity in Health and Disease

1959 ◽  
Vol 36 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Julius A. Goldbarg ◽  
Esteban P. Pineda ◽  
Benjamin M. Banks ◽  
Alexander M. Rutenburg
Keyword(s):  
Enzymatic Activity ◽  
Colorimetric Determination ◽  
Health And Disease ◽  
Urine Serum

Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

2013 ◽  
Vol 12 (7) ◽  
pp. 460-465
Author(s):  
Sameer Amereih ◽  
Zaher Barghouthi ◽  
Lamees Majjiad
Keyword(s):  
Drinking Water ◽  
Detection Limit ◽  
Complex Formation ◽  
Molar Absorptivity ◽  
Colorimetric Determination ◽  
Zirconium Complex ◽  
Reliable Determination ◽  
Percentage Recovery ◽  
Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

Colorimetric Determination of Amoxicillin in Pure and some Pharmaceutical Formulations Via Reaction with Potassium Permanganate as Oxidant Reagent

2019 ◽  
Vol 10 (02) ◽  
Author(s):  
Abbas Shebeeb Al-kadumi ◽  
Sahar Rihan Fadhel ◽  
Mohammed Abdullah Ahmed ◽  
Luma Amer Musa
Keyword(s):  
Potassium Permanganate ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Atomic Emission ◽  
Basic Medium ◽  
Photometric Method ◽  
Colorimetric Determination ◽  
Spectrophotometric Methods ◽  
Label Claim

We proposed two simple, rapid, and convenient spectrophotometric methods are described for the determination of Amoxicillin in bulk and its pharmaceutical preparations. They are based on the measurement of the flame atomic emission of potassium ion (in first method) and colorimetric determination of the green colored solution for manganite ion at 610 nm formed after reaction of Amoxicillin with potassium permanganate as oxidant agent (in the second method) in basic medium. The working conditions of the methods were investigated and optimized. Beer's law plot showed a good correlation in the concentration range of 5-45 μg/ml. The detection limits and relative standared deviations were (2.573, 2.814 μg/ml) (2.137, 2.498) for the flame emission photometric method and (1.844, 2.016 μg/ml) (1.645,1.932) for colorimetric methods for capsules and suspensions respectively. The methods were successfully applied to the determination of Amoxicillin in capsules and suspensions, and the obtained results were in good agreement with the label claim. No interference was observed from the commonly encountered additives and expectancies.

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