Pyrolidine dithiocarbamate

Y = dithiocarbamate or xanthate derivatives, found that the most active compounds have Y = pyrolidine dithiocarbamate.421... 

Water Direct introduction of water or of extract following extraction of water with methyl isobutyl ketone containing ammonium pyrolidine dithiocarbamate. AAS (Standard Method 3111 0.5 mg/L at 283.3 nm No data (%RSD = 4.7 for direct 23.5 for extract) Eaton et al. 1995b... 

The most common chelating agents used to extract metals from water samples are ammonia pyrolidine dithiocarbamate (APDC) and 8-hydroxyquinone. Methyl isobutyl ketone (MIBK) is generally used as a solvent. In a typical extraction, 1 mL of APDC is added to 50 to 100 mL of aqueous sample in a volumetric flask. The pH of the aqueous sample is adjusted for maximum extraction of the analyte of interest. Then 10 mL of MIBK is added (the volumetric ratio of sample to MIBK is usually less than 40) and the mixture is vigorously shaken for 30 seconds. The metal chelate partitions into the organic phase, which floats on the water. More water can be added to raise the organic level into the neck of the flask so that it can be... 

Marui et al. clarified the relation between oxidative stress in the arterial wall (in particular, the endothelium) and the development of the inflammatory response [19,25]. Expression of VCAM-1 by hmnan endothelial cells stimulated by cytokines such as interleukin-1 (IL-1) is mediated by redox-sensitive control mechanisms [25]. The redox-sensitive nature of this gene regulation was determined by the use of antioxidants that are active intracellularly. It was reported that the antioxidant pyrolidine dithiocarbamate (PDTC) inhibited the IL-1-induced endothelial expression of mRNA for VCAM-1 and was as effective as a monoclonal antibody against the VCAM-1 counterligand very late antigen-4 (VLA-4) in inhibiting binding of Molt-4 cells, which express VLA-4 [25]. 

AAS = atomic absorption spectroscopy APDC = ammonium pyrolidine dithiocarbamate ASV = anodic stripping voltammetry CCI4 = carbon tetrachloride DTPA =... 

Filterable metal may be analysed directly by AAS. Except in highly polluted waters, the use of flameless techniques will be necessary and research has shown that reliable results are obtained only by use of the method of standard additions to minimize matrix interferences. The sensitivity of flame methods may be enhanced if the lead is preconcentrated by extraction with ammonium pyrolidine dithiocarbamate in methyl isobutyl ketone (APDC/MIBK). This also eliminates many interferences, but prior heating of the sample with acid may be necessary to release complexed lead [8]. The use of ASV for analysis of filterable lead in water is rather more complex than might appear at first sight, since ASV is only sensitive to labile (weakly-bound) lead, and not to that strongly bound in complexes. Reduction of the sample pH by addition of an appropriate acid may cause release of most of the lead enabling analysis to be carried out. In general, AAS is to be preferred. 

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