A flow-through electrochemical cell, with a porous working electrode made of crushed glassy carbon, was used for the complete electrochemical deposition of the Mnn species from a flowing sample solution at +1.2 V versus an Ag-AgC1 reference electrode. The deposit was then dissolved galvanostatically by applying a current of between -50 and -lo00 pA while monitoring the potential of the working electrode. The measured potential values were mapped into the memory of a computer, enabling the dtldE versus E relationship and the corresponding chronopotentiometric transition times to be obtained directly. The analyte concentration was directly calculated from this value by making use of Faraday's law. The flow rate, deposition potential, pH and dissolution current were optimized. The influence of Pb2+, Fe2+ , F@+, surfactants, EDTA and humic acids on the analytical signal was studied. The method elaborated was used for analyses of water samples.

The problem of overlapping peaks of antimony and copper, as well as lead and tin, was solved by performing differential pulse anodic stripping voltammetry and differential pulse voltammetry in a 1.8 M HCI-XO"/o isopropanol supporting electrolyte media. Arsenic (111) does not interfere in the alcoholic medium and it can be determined by differential pulse voltammetry in acidic aqueous solution. The procedure has been applied to the determination of trace metals in alloy steel.

Some physicochemical properties of sodium pentamethylenedithiocarbamate and complexes with Cu(II), Ni(II), and Fe(III) were studied. The bands in the electronic and IR absorption spectra were measured and characterized, and the possibility of coulometric determination of NaS2CN(CH2)5.2 H2O was examined. The conditions for spectrophotometric determination of trace quantities of Cu(II), Ni(II), and Fe(III) as dithiocarbamate complexes were established and the stability constants of the complexes were determined.

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