Ammonium pyrrolidinedithiocarbamate

Workers at PerkinElmer (Perkin Elmer Ltd., Beaconsfield, UK, Private Communication) claim that sensitivity and precision in lead determinations in spinach were both improved by using the L vov platforms as opposed to normal off the wall techniques. This is because dependence on temperature is reduced. Johns et al. [26] has described a quantitative thin-layer chromatographic procedure for the determination of lead in plant tissues. The method is based on the use of ammonium pyrrolidinedithiocarbamate for the extraction and enrichment of lead. Instead of the previously reported conversion and visualisation of the lead complex in the short wavelength region using dithizone, the lead carbamate was converted to lead sulfide with the aid of a 6% solution of sodium sulfide in methanol/water (3 1) on silica plates, after development of the plates with toluene. See also Sects. 7.34.1,7.34.4 and 7.34.5... 

As described for vanadium and chromium also manganese is extractable from sea water into chloroform55 or methyl isobutyl ketone60 after chelation with ammonium pyrrolidinedithiocarbamate. 

A solution of both ammonium pyrrolidinedithiocarbamate and diethyldithio-carbamate has been used for eomplexing iron (Co, Ni, Cu, Zn, Cd, Pb) in sea water. The metal carbamate complexes are extracted from 500 ml of sea water at ca. pH 5 into 30 ml of Freon TF (l,l,2-trichloro-l,2,2-trifluoroethane) and back-extracted into 10 ml of 0.3 M nitric acid. The main advantage of this method is the transfer of the metals to a solution in which their concentrations do not change with time 70). 

A chamber is a useful manifold component in some applications, e.g., the spectrophotometric determination of copper with APDC (ammonium pyrrolidinedithiocarbamate) involving the production of the Cu-APDC complex and extraction into chloroform [189]. A dual-channel dropping segmentor was used for the dropwise addition of segments of the sample and reagent solutions into an unsegmented flow of organic solvent. 

A Ho(PDC)3(o-phen) complex has been obtained and studied by Xie et al. [184] from the reaction of hydrated holmium chloride, ammonium pyrrolidinedithiocarbamate (APDC) and 1,10-phenanthroline (o-phen-H20) in absolute ethanol. The enthalpy of complex formation from a solution of the reagents and the molar heat capacity of fre complex were determined by using a heat conduction microcalorimeter. The enthalpy of complex formation from the reaction of the reagents in the solid phase, was calculated on the basis of an appropriate thermochemical cycle and other auxiliary thermodynamic data. The thermodynamics of formation of the complex were investigated by the reaction in solution at the temperature range of 292.15 - 301.15 K. The constant-volume combustion energy of the complex, Act/, was also determined. 

Some of the most successful and widely used chelating reagents include dimethylglyoxime for the gravimetric determination of nickel 1,10-phe-nanthroline and its derivatives for the colorimetric determination of iron and copper dithizone for the separation and colorimetric determination of a number of metals but particularly lead, silver, zinc, cadmium, and mercury the dithiocarbamates such as diethylammonium diethyldithiocarbamate and ammonium pyrrolidinedithiocarbamate, used for colorimetry but more widely applied now as selective extractants and the most successful titrant, EDTA. 

A dual-conical gravitational phase separator has been proposed for determining Cu and Pb in urine. A citrate-buffered medium (pH 3) serves to form analyte-ammonium pyrrolidinedithiocarbamate neutral complexes. These are then extracted into isobutyl ketone, and the organic phase separated by means of a dual-conical gravitational phase separator and... 

Solvent in all extractions isobutyl methyl ketone APDC = ammonium pyrrolidinedithiocarbamate DDDC = diethylammonium diethyl dithiocarbonate TIO = tri-iso-octylamine TTA = thenoyltrifluoroacetone ( ) indicates partial extraction... 

In this approach, the sample is initially mixed with a reagent and the analyte precipitates as an insoluble salt. The precipitate is accumulated, washed and then dissolved for introduction into the ICP-MS apparatus. Analytes are precipitated as either hydroxides or with organic reagents (e.g. ammonium pyrrolidinedithiocarbamate, APDC, sodium diethyldithiocarbamate, NaDDTC). A common problem of the precipitation and co-precipitation methods is that analytes are not quantitatively separated from the matrix. 

As an alternative to generating the complex prior to injection onto the column, in situ formation of the complex on the column was examined by including M ammonium pyrrolidinedithiocarbamate in the... 

APDC Solution Transfer 2.00 g of APDC (ammonium 1-pyrrolidinedithiocarbamate) (Aldrich Chemical, or equivalent) into a 100-mL volumetric flask, dilute to volume with water, and mix. Remove insoluble free acid and other impurities normally present by two to three extractions with 10-mL portions of Aqueous Butyl Acetate. 

The bismuth active substances (BiAS) method for the determination of nonionic surfactants with barium tetraiodobismuthate (BaBil4, modified Dragendorff reagent) is used in the standardized (DIN-Norm) procedure in Germany, as well as in other countries. Ba as a hard Lewis acid forms cationic coordination complexes with the polyethoxylate chain of the nonionic surfactants, which are precipitated by [Bim in the presence of acetic acid. The orange precipitate is then dissolved with ammonium tartrate solution, and the released bismuth ions are determined by potentiometric titration with pyrrolidinedithiocarbamate solution. Waters et al. optimized the BiAS procedure by introduction of a cation/anion exchange clean-up of the sublation extracts. The BiAS procedure fails to determine ethoxylates with less than five ethoxy units because these compounds are not precipitated by barium tetraiodobismuthate. Thus, this procedure is not suitable for determination of APEO metabolites, i.e., the shorter APEO and AP. ... 

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