A Simplification and Improvement in the Determination of Copper in Fabrics and Rubberized Materials

1932 ◽  
Vol 5 (3) ◽  
pp. 356-359
Author(s):  
F. Kirchhof
Keyword(s):  
Nitric Acid ◽  
Colorimetric Method ◽  
Test Solution ◽  
Ferric Ion ◽  
The Past ◽  
Equivalent Quantity ◽  
Determination Of Copper

Abstract The determination of small quantities of copper in fabrics and in rubberized materials can be simplified by destruction with concentrated nitric acid, which accelerates the ignition to the final ash. At the same time, this method avoids the usual danger of volatilization of copper as chloride as a result of the presence of chlorine from white factice or from cold vulcanization. Likewise, precipitation of the copper as sulfide can be avoided by repeating the precipitation of the extract from the ash, which contains predominantly aluminum and iron, with ammonia. In this second precipitation, only around 1 to 2 per cent of the total quantity of copper is retained in the precipitate and filter, and this quantity may in most cases be neglected. The ordinary colorimetric method used in the past for the detection of copper as complex cuprammonium ion can be made about ten times as sensitive by making use of the reaction: Cu+ + + 2I− → CuI + I. This is, however, applicable only in the complete absence of the ferric ion and of nitric acid in the test solution. The sensitivity can be increased still more by the addition of starch. Another advantage of the determination of copper by measurement of the equivalent quantity of iodine lies in the fact that, if necessary, only one-tenth as much sample need be used, but in this case as in all such determinations, the copper must be distributed uniformly throughout the material to be analyzed.

Collaborative Study Using a ZDBT Colorimetric Method for the Determination of Copper in Alcoholic Products

1967 ◽  
Vol 50 (2) ◽  
pp. 334-338
Author(s):  
Duane H Strunk ◽  
A A Andreasen
Keyword(s):  
Sulfuric Acid ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Colorimetric Method ◽  
Good Precision ◽  
Determination Of Copper

Abstract Results are given on a collaborative study in which a zinc dibenzyldithiocarbamate (ZDBT) colorimetric method is used to measure copper in alcoholic products such as high wine, spirits, gin, whisky, brandy, rum, and wine. In this method, the sample is made ca 0.SN with sulfuric acid, and carbon tetrachloride containing 0.2% ZDBT is added. The colored copper-ZDBT complex is extracted in the carbon tetrachloride and measured at 438 mμ against a similar carbon tetrachloride extract of a blank. Data show good precision, and it is recommended that the ZDBT method be adopted as official, first action.

A Rapid Colorimetric Method for the Quantitative Determination of Copper Oxidase Activity (Ceruloplasmin)

1958 ◽  
Vol 4 (6) ◽  
pp. 519-523 ◽  
Author(s):  
O Boyd Houchin
Keyword(s):  
Quantitative Determination ◽  
Oxidase Activity ◽  
Clinical Laboratory ◽  
Colorimetric Method ◽  
Laboratory Equipment ◽  
Rapid Procedure ◽  
Copper Oxidase ◽  
Determination Of Copper

Abstract A rapid procedure for determining quantitatively copper oxidase activity of plasma or serum is described. It is calibrated against determined amounts of ceruloplasmin and can be adapted to usual clinical laboratory equipment for the quantitative determination of ceruloplasmin.

A Colorimetric Method for the Determination of Esters

1950 ◽  
Vol 3 (1) ◽  
pp. 128 ◽  
Author(s):  
AR Thompson
Keyword(s):  
Absorption Spectra ◽  
Colorimetric Method ◽  
Hydroxamic Acids ◽  
Degree Of Conversion ◽  
Maximum Absorption ◽  
Ferric Ion ◽  
Factors Influencing ◽  
Ferric Hydroxamate ◽  
Volatile Esters

The colorimetric method of Hill, based on conversion of esters to hydroxamic acids which form red complexes with ferric ion, has been adapted for the estimation of volatile esters. Investigation of the factors influencing the two reactions involved has led to a satisfactory procedure for esters derived from acids with an unbranched chain of two to ten carbon atoms and esters of isobutyric and isovaleric acids. The degree of conversion to ferric hydroxamate complexes has been found by reference to pure hydroxamic acids. The absorption spectra of the ferric hydroxamate complexes from all the esters examined show a maximum absorption at 520 mμ. Hence a mixture of esters may be estimated in terms of one of the esters.

Determination of Copper in Raw Materials Used in the Rubber Industry

1950 ◽  
Vol 23 (4) ◽  
pp. 972-974
Author(s):  
J. Genova ◽  
A. Addobbati
Keyword(s):  
Raw Materials ◽  
Colorimetric Method ◽  
Gum Arabic ◽  
Ammonium Hydroxide ◽  
Sodium Diethyldithiocarbamate ◽  
Repeated Treatment ◽  
Cent Solution ◽  
Materials Used ◽  
Determination Of Copper

Abstract Because of its catalytic action on the deterioration of rubber, the presence of copper in rubber products, even in very small quantities (0.001 per cent), may lead to serious difficulties which shorten the useful life of the products. Most of the raw materials used in the manufacture of these products contain small percentages of copper, and its determination is best made by the colorimetric method. Various reagents can be used for this purpose, among them dithizone (phenylazothionoformic acid phenylhydrazide) and sodium diethyldithiocarbamate. The use of the latter was proposed by Callan and Henderson. The method specified by the A.S.T.M. for the determination of copper in rubber products is based on their work. This method may be briefly described as follows. The destruction of the organic matter and dissolution of the sample is effected by digestion with sulfuric acid in a Kjeldahl flask, followed by treatment with fuming nitric acid and hydrogen peroxide. Repeated treatment and final evaporation to the point where white fumes are evolved eliminates any colored substances and any excess of oxidizing agents. The sesquioxides are precipitated by ammonium hydroxide, and an aliquot part of the filtrate obtained is transferred to a Nessler tube. One cc. of 5 per cent solution of gum arabic, 10 cc. of ammonium hydroxide (d. 0.90), and 10 cc. of 0.1 per cent solution of sodium diethyldithiocarbamate are added. The presence of copper is indicated by the formation of its gray colored carbamate, which, because of its colloidal nature, remains in suspension.

Determination of Phosphorus in Fruits and Fruit Products by a Spectrophotometry Molybdovanadate Method and by the Official Gravimetric Quinoline Molybdate Fertilizer Method

1969 ◽  
Vol 52 (4) ◽  
pp. 865-870
Author(s):  
Ben Estrin ◽  
Wallace S Brammell
Keyword(s):  
Nitric Acid ◽  
Perchloric Acid ◽  
Colorimetric Method ◽  
Volumetric Method ◽  
Dry Ashing ◽  
Ash Weight ◽  
Molybdate Method ◽  
Phosphorus Determination ◽  
Good Agreement

Abstract A newly developed spectrophotometric molybdovanadate method and the official gravimetric quinoline molybdate fertilizer method, 2.025(b), slightly modified, were used to determine phosphorus in fruits and fruit products. In the former method, the use of hazardous perchloric acid is avoided by dry-ashing the sample as in method 20.017 and by using nitric acid rather than perchloric acid in the molybdovanadate reagent. In the quinoline molybdate method, the sample is dry-ashed in the same way. In both proposed methods, the official ash solution is used for the phosphorus determination as in the official volumetric method, 20.031–20.032. Ash weight can be obtained before preparing this solution; in the official colorimetric method, however, a second aliquot must be dry-ashed for the ash weight. The two proposed methods gave results in good agreement with those obtained by the official volumetric method. These methods are simpler and faster than the two present official methods.

scholarly journals VOLTAMETRIC DETERMINATION OF Cu IN FUEL USING CHEMICALLY MODIFIED ELECTRODE BY TETRAZOLES

2019 ◽  
Vol 16 (31) ◽  
pp. 660-673
Author(s):  
Lucy Rose de Mª O MOREIRA ◽  
Janiciara Botelho SILVA ◽  
Jethânia Glasses Cutrim FURTADO ◽  
Aldaléa Lopes Brandes MARQUES ◽  
Cícero Wellington Brito BEZERRA ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Modified Electrode ◽  
Metal Ion ◽  
Limit Of Detection ◽  
Chemically Modified Electrode ◽  
Chemically Modified ◽  
Environment And Health ◽  
Certainty Level ◽  
Determination Of Copper

This article describes an analytical procedure for the determination of copper in fuel samples using the modified graphite electrode basal pyrolysis (BPPGME) by tetrazolium salts: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2Htetrazolium (MTT) Br]. The determination of metals in fuel is an issue of environmental relevance because it believes that these elements can be released into the atmosphere causing damage to the environment and health. Fuel samples (ethanol, biodiesel and gasoline) were previously digested in a microwave oven using nitric acid and peroxides (biodiesel) and only nitric acid (alcohol and gasoline). The metal ion studied reacted on the surface of the chemically modified electrode to produce marked changes in the corresponding voltammograms. In order to determine the species of interest the best results were at pH 5.0 for copper and pH 6.0 for other species. The concentration scale for copper was 2.0x10-6 at 1.25 X 10-5 mol L-1. The limit of detection in fuels of samples (ethanol, biodiesel or gasoline), by ARV was 2.5x10-6 mol L-1. The accuracy of the proposed technique was compared by providing similar results, ie the copper concentration in the samples analyzed by both techniques at a non-statistically different 95% certainty level.

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