Copper diethyldithiocarbamate

Sodium diethyldithiocarbamate, dimethyldithiocarbamate and disulphuram are potent inhibitors of the enzyme dopamine-0-hydroxylase of brain, possibly because of chelation of copper. The copper-diethyldithiocarbamate complex penetrates the central nervous system more readily than does copper ion, itself. These effects slow the disappearance of pentobarbitone from plasma and produce behavioural changes in rats180. ... 

Nalbandyan, 1982 Hodgson and Fridovich, 1975 Asada et al., 1975), whereas azide inhibits the enzymes in the following order iron > manganese > copper/zinc superoxide dismutase (Misra and Fridovich, 1978). Diethyldithiocarbamate is another well-characterized inhibitor of the copper/zinc superoxide dismutase (Heikkila et al., 1977). It forms a complex with the copper and removes the metal from all the protein ligands. The copper-diethyldithiocarbamate complex can be separated without affecting the zinc content of the protein (Cocco et al., 1981). 

For the determination of lead in drinking and surface waters photometry is preferred. Lead ions form a colourless compound extractable with tetrachloromethane with diethyldithiocarbamate C5HjoNS2Na at pH 11-12.5, which reacts with copper ions to form yellow-brown copper diethyldithiocarbamate. Absorbance is measured at 435 nm (violet filter). The method is used for the determination of lead at concentrations of > 0.01 mg 1 [13]. 

Table 11.5 shows that some complexes are more powerful oxidizing agents than the free metal cations. Such complexes could cause the destruction of vital metabolites, e.g. the copper diethyldithiocarbamate chelate destroys thioctic acid 2.28) (Sijpesteijn and Janssen, 1959). 

A solution of lead diethyldithiocarbamate in chloroform reacts with copper salts in acid solution forming the red copper diethyldithiocarbamate which is also soluble in chloroform. This reagent is highly specific for Cu. 

CU9S5 NCs have been synthesised by the thermal decomposition of a copper diethyldithiocarbamate precursor in OAm at 300 °C. XRD patterns of the as-synthesised NCs suggested the rhombohedral phase and TEM... 

Copper diethyldithiocarbamate is destroyed by cyanide whilst the bismuth complex is not. If, therefore, the carbon tetrachloride layer is shaken with a 5 per cent potassium cyanide solution and does not decolorise, bismuth is present. Jenkins observed that the bismuth complex in carbon tetrachloride is not stable to washing with sodium hydroxide, hence if its presence is indicated by the cyanide test, the original extraction procedure should be repeated but before measurement of the extinction, the carbon tetrachloride solution should be extracted with two portions of 10 ml of N sodium hydroxide. 

Colorimetric procedures are often used to determine copper in trace amounts. Extraction of copper using diethyldithiocarbamate can be quite selective (60,62), but the method using dithhone is preferred because of its greater sensitivity and selectivity (50—52). Atomic absorption spectroscopy, atomic emission spectroscopy, x-ray fluorescence, and polargraphy are specific and sensitive methods for the deterrnination of trace level copper. 

Discussion. Sodium diethyldithiocarbamate (B) reacts with a weakly acidic or ammoniacal solution of copper(II) in low concentration to produce a brown colloidal suspension of the copper(II) diethyldithiocarbamate. The suspension may be extracted with an organic solvent (chloroform, carbon tetrachloride or butyl acetate) and the coloured extract analysed spectrophotometrically at 560 nm (butyl acetate) or 435 nm (chloroform or carbon tetrachloride). 

Procedure. Dissolve 0.0393 g of pure copper(II) sulphate pentahydrate in 1 L of water in a graduated flask. Pipette 10.0 mL of this solution (containing about 100 jug Cu) into a beaker, add 5.0 mL of 25 per cent aqueous citric acid solution, render slightly alkaline with dilute ammonia solution and boil off the excess of ammonia alternatively, adjust to pH 8.5 using a pH meter. Add 15.0mL of 4 per cent EDTA solution and cool to room temperature. Transfer to a separatory funnel, add lOmL of 0.2 per cent aqueous sodium diethyldithiocarbamate solution, and shake for 45 seconds. A yellow-brown colour develops in the solution. Pipette 20 mL of butyl acetate (ethanoate) into the funnel and shake for 30 seconds. The organic layer acquires a yellow colour. Cool, shake for 15 seconds and allow the phases to separate. Remove the lower aqueous... 

Procedure (tin in canned foods). The procedure provides for the removal of interfering copper by the addition of diethylammonium diethyldithiocarbamate in chloroform reagent. ... 

If copper is known to be absent or present only in negligible proportions, dilute the solution with water to 50 mL in a graduated flask, and continue as detailed below. Otherwise, transfer the solution to a small separatory funnel and add 5 mL of the diethylammonium diethyldithiocarbamate in chloroform reagent (diluted 1 20 with chloroform when required). Shake and run off the chloroform layer, extract the aqueous layer with successive 1 mL portions of the reagent until the chloroform layer is colourless finally, wash the aqueous layer with a few mL of chloroform. Dilute the aqueous solution with water to 50 mL in a graduated flask. 

Selenium is extracted as diethyldithiocarbamate complex from the solution containing citrate and EDTA [5]. Ohta and Suzuki [6] found that only a few elements, such as copper, bismuth, arsenic, antimony, and tellurium, are also extracted together with selenium. They examined this for effects of hundredfold amounts of elements co-extracted with the selenium diethyldithiocarbamate complex. An appreciable improvement of interferences from diverse elements was observed in the presence of copper. Silver depressed the selenium absorption in the case of atomisation of diethyldithiocarbamate complex, but the interference of silver was suppressed in the presence of copper. The atomisation profile from diethyldithiocarbamate complex was identical with that from selenide. 

Several ions (e.g., manganese, iron (II), iron (III), cobalt, nickel, copper, zinc, cadmium, lead, and uranyl) react with pyrocatechol violet, and to some extent are extracted together with aluminium. The interferences from these ions and other metal ions generally present in seawater could be eliminated by extraction with diethyldithiocarbamate as masking agent. With this agent most of the metal ions except aluminium were extracted into chloroform, and other metal ions did not react in the amounts commonly found in seawater. Levels of aluminium between 6 and 6.3 pg/1 were found in Pacific Ocean and Japan Sea samples by this method. 

A Cis column loaded with sodium diethyldithiocarbamate has been used to extract copper and cadmium from seawater. Detection limits for analysis by graphite furnace atomic absorption spectrometry were 0.024 pg/1 and 0.004 xg/l, respectively [283]. 

Traces of copper and lead are separated [301] from macro amounts of calcium, magnesium, sodium, and potassium by adsorption from the sample onto active carbon modified with hydroxyquinoline dithizone or diethyldithiocarbamate. 

Chakraborti et al. [665] determined cadmium, cobalt, copper, iron, nickel, and lead in seawater by chelation with diethyldithiocarbamate from a 500 ml sample, extraction into carbon tetrachloride, evaporation to dryness, and redissolution in nitric acid prior to determination by electrothermal atomic absorption spectrometry in amounts ranging from 10 pg (cadmium) to 250 pg (nickel). 

Copper Adsorption on hydroxyquinoline, dithizone or diethyldithiocarbamate modified charcoal Miscellaneous [301]... 

Tellurium-containing donors, synthesis and manufacture of, 22 212 Tellurium-copper alloys, 24 425-426 Tellurium crystals, 24 405-406 Tellurium decafluoride, 24 419 Tellurium dibromide, 24 420 Tellurium dichloride, 24 419-420 Tellurium diethyldithiocarbamate, 24 411 Tellurium dimethylthiocarbamate, 24 428 Tellurium dioxide, 24 407-408, 409, 411, 420, 428... 

Metal Coatings. Tellurium chlorides, as well as tellurium dioxide in hydrochloric acid solution, impart permanent and attractive black antique finish to silverware, aluminum, and brass. Anodized aluminum is colored dark gold by tellurium electro deposition. A solution containing sodium tellurate and copper ions forms a black or blue-black coating on ferrous and nonferrous metals and alloys. Addition of sodium tellurite improves the corrosion resistance of electroplated nickel. Tellurium diethyldithiocarbamate is an additive in bright copper electroplating (see Electroplating). 

Edward Iratami [273] applied high performance liquid chromatography to the determination in river water of mercury(II), copper(II), nickel(II), cobalt(II) and lead(II) as their dithizonates and their diethyldithiocarbamates. The metals were first complexed, then the complexes... 

Liquid chromatography-absorption spectrophotometry was used by Vlacil and Hamplova [281] for the determination of lead and copper in natural waters. The metal diethyldithiocarbamates are extracted and concentrated by evaporation, followed by reversed phase liquid chromatography of the chelates. The copper and lead chelates can also be sequentially detected by spectrophotometry at 440 and 280nm. The detection limits for copper and lead were 8.6 and 17pg L 1 respectively, when liquid chromatography was used, and were 58 and 17pg L respectively when spectrophotometry was used. 

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