New modified colorimetric method of determination of copper in biological materials with sodium diethyldithiocarbamate

1951 ◽  
Vol 36-37 (2) ◽  
pp. 958-966 ◽  
Author(s):  
Kenjiro Kimura ◽  
Yukio Murakami
Keyword(s):  
Colorimetric Method ◽  
Biological Materials ◽  
Sodium Diethyldithiocarbamate ◽  
Method Of Determination ◽  
Determination Of Copper

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.

scholarly journals A New Colorimetric Method of Determination of O, O-Dimethyl 2, 2-Dichlorovinyl Phosphate in Insecticidal Preparations

1975 ◽  
Vol 95 (12) ◽  
pp. 1483-1491 ◽  
Author(s):  
HIROYASU OGATA ◽  
EMIKO SAITO ◽  
HISAKO MURATA ◽  
TOSHIO SHIBAZAKI ◽  
TETSUO INOUE
Keyword(s):  
Colorimetric Method ◽  
Method Of Determination

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 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.

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