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 Copper in Rubber Latex

1951 ◽  
Vol 24 (2) ◽  
pp. 472-481
Author(s):  
F. C. J. Poulton ◽  
M. E. Tunnicliffe
Keyword(s):  
Aqueous Solution ◽  
Carbon Tetrachloride ◽  
Ferric Iron ◽  
Potassium Cyanide ◽  
Zinc Salt ◽  
Colorimetric Determination ◽  
Rubber Latex ◽  
Experimental Conditions ◽  
Carbon Tetrachloride Solution

Abstract Small amounts of copper in rubber latex can be determined by following a dry-ashing procedure for removal of organic matter and concluding with a colorimetric determination of the copper in the ash. Provided the ignition is not undubly prolonged, the ashing temperature can safely rise to 800° C, and recovery of the copper is complete from the ash when a mixture of nitric and hydrochloric acids is used. Results are slightly higher than those obtained by the wet oxidation process. Assay of the copper can be carried out on the solution of the ash, either in aqueous medium or in carbon tetrachloride solution, depending on the extent of interference anticipated from iron and insoluble ingredients, such as clay, and on the degree of accuracy required. Visual color matching in aqueous solution is simpler and quicker, but insoluble material may give rise to considerable personal error. In aqueous solution, the copper equivalent of ferric iron is about 1/100, i.e., the coloration is about 100 times more intense for copper than for iron. for more accurate work, measurement of the color of a carbon tetrachloride solution of the copper diethyldithiocarbamate complex by means of a suitable colorimeter is recommended. The tendency of the complex to fade is overcome by replacing the sodium diethyldithiocarbamate by the zinc salt dissolved in carbon tetrachloride. In such a solution the copper equivalent of ferric iron is about 1/1000, but actual experimental conditions can vary this figure between wide limits. A more satisfactory procedure is, therefore, to measure the total color developed in carbon tetrachloride, and then bleach out the color due to copper with potassium cyanide. The residual (interfering) colors can thus be estimated, and the difference between the readings gives a direct measure of the concentrations of copper in the test solution.

Colorimetric Determination of Mestranol in Combination with Ethynodiol Diacetate

1975 ◽  
Vol 58 (1) ◽  
pp. 75-79
Author(s):  
John Y P Wu
Keyword(s):  
Sulfuric Acid ◽  
Oral Contraceptive ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Collaborative Study ◽  
Chromatographic Column ◽  
Color Reaction ◽  
Colorimetric Determination ◽  
Ethynodiol Diacetate

Abstract Mestranol in combination with ethynodiol diacetate, an oral contraceptive formulation, is isolated from the sample on a partition chromatographic column prior to colorimetric determination. The color reaction which is specific for estrogens is formed by shaking an aliquot of the heptane eluate of mestranol with a 30% methanol-sulfuric acid solution. A collaborative study of the method gave results of 99.8% of added mestranol for the simulated mix and 100.7% of labeled mestranol for the commercial tablet. The method has been adopted as official first action.

Determination of Hydroperoxides in Rubber and Synthetic Polymers

1947 ◽  
Vol 20 (1) ◽  
pp. 45-54
Author(s):  
H. A. Laitinen ◽  
J. S. Nelson
Keyword(s):  
Acid Solution ◽  
Ferrous Iron ◽  
Synthetic Polymers ◽  
Colorimetric Determination ◽  
Thiocyanate Complex ◽  
Styrene Copolymer ◽  
Ferric Thiocyanate ◽  
Ferric Salt ◽  
Butadiene Styrene

Abstract Ferrous iron has been used as a reagent for the determination of peroxide by numerous investigators. Yule and Wilson estimated peroxide in cracked gasoline by shaking with an acid solution of ferrous thiocyanate and back-titrating the resulting ferric salt with titanous chloride. The method was criticized by Young, Vogt, and Nieuwland, who used the color of the resulting ferric thiocyanate complex as a basis for a colorimetric determination of peroxide. In this procedure methanol was used as the solvent. Bolland, Sundralingam, Sutton and Tristram modified the method to enable rubber samples to be analyzed by changing the solvent to a mixture of benzene and methanol (73 per cent benzene by volume). For determining peroxide in GR-S (butadiene-styrene copolymer) and other butadiene copolymers it would be desirable to employ a solvent rich in benzene, since these polymers tend towards insolubility upon oxidation. A solvent composed largely of benzene would also improve the sensitivity of the determination, since larger quantities of polymer could be dissolved in a given volume of solvent.

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.

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