Sodium diethyldithiocarbamate

Sodium diethyldithiocarbamate was introduced for the treatment of nickel carbonyl intoxication (Sunderman 1990), for which it is very effective. The use of this compound is not recommended for other toxic metals because of the lipid-soluble complexes which it forms with many of them. Such complexes readily pass into the central nervous system. 

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Nickel carbonyl should be used in totally enclosed systems or under good local exhaust. Plants and laboratories where nickel carbonyl is used should make use of air-monitoring devices, alarms should be present in case of accidental leakage, and appropriate personal respiratory protective devices should be readily available for emergency uses. Monitoring of urinary nickel levels is useful to help determine the severity of exposure and identify appropriate treatment measures. Some large-scale users of nickel carbonyl maintain a supply of sodium diethyldithiocarbamate, or Antabuse, a therapeutic agent, on hand for use in case of overexposure. 

In this work, atmospheric particles (PM 10 and PM 2.5) were collected by a dichotomos air sampler. Several leaching procedures were investigated for decomposition of heavy metals. The digests were pre-concentrated with sodium diethyldithiocarbamate. The determinations were canted out on a Vartan Model AA-220 atomic absorption spectrometer. The instrarment was equipped with a GTA-110 graphite furnace system. Table 1 shows the concentrations of heavy metals associated with PM 10 and PM 2.5 particles. Table 1. Concentrations of heavy metals in PM 10 and PM 2.5 atmospheric particles (ng/m )... 

Procedures have also been devised for the determination of metallic constituents. Thus, mercury is absorbed in nitric acid and titrated with sodium diethyldithiocarbamate, whilst zinc is absorbed in hydrochloric acid and determined by an EDTA titration (see Section 10.65). 

Sodium diethyldithiocarbamate, (C2H5)2N CS S Na+. This reagent is generally used as a 2 per cent aqueous solution it decomposes rapidly in solutions of low pH. It is an effective extraction reagent for over 20 metals into various organic solvents, such as chloroform, carbon tetrachloride, and ethanol. The selectivity is enhanced by the control of pH and the addition of masking agents. 

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... 

Sodium diethyldithiocarbamate ( NaDDC ). Dissolve 1 gin 50 mL of de-ionised water and filter if necessary. This reagent must be freshly prepared. 

Thiourea and allylthiourea (20), D-xylulose (22), sodium diethyldithiocarbamate, L-methionine, and -propyl-di- -propylthiol-carbamate (163), 12 6-(substituted) purines (166), and two coumarin derivatives (164) have been found to promote Striga seed germination. None of these materials, however, appear to be constituents of the natural stimulant preparations. 

Alternatively, an aqueous solution of sodium diethyldithiocarbamate (3.5%, 2 ml) or freshly prepared solution of dithizone in chloroform (0.1%, 10 ml) was added to sample A. The metal diethyldithiocarbamates (termed sample B) or metal dithizon-ates (termed sample C) thus formed were extracted in chloroform. The volume of chloroform extract was reduced to 1.0 ml. Aliquots (10 pi) each of sample B and sample C were chromatographed on plates coated with 0.25-mm layer of silica gel G using benzene -t methyl isopropylketone (50 1) and toluene -r chloroform (50 1), respectively, as mobile phases. Metal dithizonates were self-detected. The namral colored metal diethyldithiocarbamates were converted into brown spots by spraying... 

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]. 

Moore [355] used the solvent extraction procedure of Danielson et al. [119] to determine iron in frozen seawater. To a 200 ml aliquot of sample was added lml of a solution containing sodium diethyldithiocarbamate (1% w/v) and ammonium pyrrolidine dithiocarbamate (1 % w/v) at pH to 4. The solution was extracted three times with 5 ml volumes of 1,1,2 trichloro-1,2,2 trifluoroethane, and the organic phase evaporated to dryness in a silica vial and treated with 0.1 ml Ultrex hydrogen peroxide (30%) to initiate the decomposition of organic matter present. After an hour or more, 0.5 ml 0.1 M hydrochloric acid was added and the solution irradiated with a 1000 W Hanovia medium pressure mercury vapour discharge tube at a distance of 4 cm for 18 minutes. The iron in the concentrate was then compared with standards in 0.1 M hydrochloric acid using a Perkin-Elmer Model 403 Spectrophotometer fitted with a Perkin-Elmer graphite furnace (HGA 2200). 

In many applications, such as the analysis of mercury in open ocean seawater, where the mercury concentrations can be as small as 10 ng/1 [468,472-476], a preconcentration stage is generally necessary. A preliminary concentration step may separate mercury from interfering substances, and the lowered detection limits attained are most desirable when sample quantity is limited. Concentration of mercury prior to measurement has been commonly achieved either by amalgamation on a noble-metal metal [460,467, 469,472], or by dithizone extraction [462,472,475] or extraction with sodium diethyldithiocarbamate [475]. Preconcentration and separation of mercury has also been accomplished using a cold trap at the temperature of liquid nitrogen. 

X-ray fluorescence was used for the determination of molybdenum in seawater in a method described by Kimura et al. [511]. Molybdenum is coprecipitated with sodium diethyldithiocarbamate, which is measured by X-ray fluorescence. They report a detection limit of 0.3 xg/l and a relative standard deviation of 2.9%. 

Yang et al. [588] have described a spectrophotometric method for the determination of dissolved titanium in seawater after preconcentration using sodium diethyldithiocarbamate. See also Sect. 5.74.14. 

Lieser et al. [628] studied the application of neutron activation analysis to the determination of trace elements in seawater, with particular reference to the limits of detection and reproducibility obtained for different elements when comparing various preliminary concentration techniques such as adsorption on charcoal, cellulose, and quartz, and complexing agents such as dithizone and sodium diethyldithiocarbamate. 

In these procedures 1 litre of seawater was shaken with 60 mg charcoal for 15 min. Complexing agents were added in amounts of 1 mg, dissolved in 1 ml of acetone. The pH was 5.5, or it was adjusted to 8.5 by addition of 0.1 M ammonia. The charcoal was filtered off and irradiated. Results of three sets of experiments with charcoal alone, charcoal in the presence of dithizone, and charcoal in the presence of sodium diethyldithiocarbamate are compared. The following elements are adsorbed to an extent from 75 to 100% silver, gold, cerium, cadmium, cobalt, chromium, europium, iron, mercury, lanthanum, scandium, uranium, and zinc. The amount of sodium is reduced to about 10 6, bromine to about 10 5, and calcium to about 10 2. 

Thallium has been determined in 10 ml of ashed serum or in urine by extracting with sodium diethyldithiocarbamate into MIBK n°). More recently, Savory and co-workers 1131 described a wet digestion procedure for 50 ml of urine or 5 ml of serum in which the thallium is separated by extracting the bromide into ether, evaporating the ether and then taking up in dilute acid for aspiration. As little as 0.1 ppm is determined in urine. Curry et al.114) determined less than 1 ng of thallium in 200 /d of urine by using the tantalum sample boat technique. The sample in the boat is dried by holding the boat 1 cm from the flame and then it is inserted into the flame where it is vaporized. A similar procedure is used for >3 ng of thallium in 50-100/al of blood, except that the blood is preashed with 3 drops of nitric acid. Since the tantalum boat method is susceptible to interelement interferences, the method of standard additions is used for calibration. 

Berman u°) could determine as little as 0.005 ppm cadmium in serum and 0.002 ppm in urine by extracting the cadmium from the digest with lead in sodium diethyldithiocarbamate into MIBK. Torres 112) isolated cadmium from urine by ion exchange chromatography. 

Sodium dichromate, 6 522, 9 630-632 manufacture, 6 538-543 U.S. exports, 6 544t U.S. imports for consumption, 6 545t Sodium dichromateCVI) dihydrate physical properties, 6 528t Sodium dicyanamide, 8 160 Sodium diethyldithiocarbamate molecular formula, 5 713t... 

The latter case has been demonstrated with the reaction of [ReCl3(PPh3)2(CH3CN)] with a large excess of sodium diethyldithiocarbamate which results in sulfur abstraction and in the formation of a mixed phosphine/diethyldithiocarbamato/r/ -thiocarbamoyl complex. For the molecular structure of this compound see formula (225) which represents that of the corresponding rhe-nium(IV) cation which is formed by oxidation of the primarily formed Re complex and contains one rhenium-carbon bond. The formation of thiocarbamoyl compounds seems to be an essential... 

A round-bottom flask was charged with 20 ml of THF, the step 1 product (2.2 mmol), sodium diethyldithiocarbamate (2.2 mmol), and methanesulfonic acid (5 mol%) and... 

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