Spectrophotometric Determination of Copper Following Extraction with 1,5-Diphenylcarbohydrazide in Benzene

Abstract

and transmitted illumination. With the proper combination of lighting, the reaction spots for sulfuric acid appear as milky yellow, perfectly circular areas on a blue background. Most other acids will give yellow spots, but these will not contain the milky precipitate of barium sulfate.Phosphoric acid will also cause a milky precipitate within the reaction area; however, the barium phosphate formed is birefringent, in contrast to barium sulfate. The two can therefore be distinguished by means of crossed polars. Other sulfates and phosphates will give circular milky areas, but for the most part were not found to be sufficiently acidic to change the color of bromophenol blue.It was difficult to reproduce precisely the relationship between sulfuric acid droplet diameter and reaction spot di-ameter, presumably because of the sensitivity of the sulfuric acid droplet diameter to relative humidity. However, as a result of a large number of experiments, it is believed that the equation Dh = 2.5 Dd where Dh is the diameter of the reaction spot or "halo" and Du is the equivalent diameter of a droplet of pure sulfuric acid, represents the droplet size within ±30%. The equation is not valid above approximately 90% relative humidity. At extremely high humidities, the test fails because of the extreme dilution of the sulfuric acid drops.

The nature of the copper complexes in bile and their relationship to the absorption and excretion of copper in normal subjects and in Wilson's disease

“…The residue was reextracted with petroleum ether (20 ml), the supernatants were combined, and the cycle was repeated with the next solvent. Extracts were evaporated and copper was determined colorimetrically following perchloric acid digestion (Stoner and Dasler, 1960 The nature of the copper complexes in bile shaken with just sufficient water to form an emulsion, and Russell's viper venom (1.0 mg) added. The mixture was incubated at room temperature overnight then evaporated in vacuo.…”

“…The method was that of Stoner and Dasler (1960) 223 with the modification that 15-0 ml of saturated N3P04 was used. Accuracy and precision were similar to the published values when the digestion time was not less than one hour.…”

Ferrous Metallurgy

“…COPPER _ Copper was determined by use of the biuret reaction (116), its color reaction with oxalyldihydrazine in the presence of acetaldehyde (51), or with 2,2'biquinolyl (295) without separation from iron. Biscyclohexanone oxalyldihydrazine was used for the color development after separation of iron (234) Copper was extracted from iron with 2,2'biquinolyl in amyl alcohol (106), with 1,2di -(0 -aminobenzylideneamino) ethane in benzene (224), with dithiocarbamate in carbon tetrachloride (266), and with 1,5-diphenylcarbohydrazide in benzene (309) as basis for its determination.…”

Green Downscaling of Solvent Extractive Determination Employing Coconut Oil as Natural Solvent with Smartphone Colorimetric Detection: Demonstrating the Concept via Cu(II) Assay Using 1,5-Diphenylcarbazide

“…Spectrophotometric determination of Cd(II) using dithizone was performed by extracting the complex into chloroform [ 1 ]. Using 1,5-diphenylcabazide (DPC), Cu(II) could be determined spectrophotometrically after extracting into benzene [ 2 ]. Fe(II) and Fe(III) could be extracted into 1-pentanol using anthranilic acid for spectrophotometric determination [ 3 ].…”