A procedure was developed for sample preparation for the further determination of arsenic in potable and natural water and process solutions by stripping voltammetry (SV). To minimize the losses and simplify the procedure, arsenic(III) was oxidized by the ozonation or UV irradiation of the solution in the presence of sulfite, chloride, or hydroxide ions, which increased the oxidation efficiency. The time required for 100% oxidation does not exceed 60 s for an arsenic concentration of no more than 1 mg/L. The reduction to arsenic(III) was performed photochemically in the presence of sodium sulfite for 5 min. Further stripping voltammetric determination was performed in the same solution using a gold-plated carbon electrode. The developed procedure is rapid, simple, and easy-to-automate.

In this report the theory of the reversible process of amalgam formation and dissolution reaction at a mercury film electrode of different thickness is developed using an additional boundary condition approach for asymmetrical diffusion. The profile of the entire voltammetric peak is simulated using a wide range of values of the parameter H=lσ/D (where l is the film thickness, σ=nFW/RT, D is diffusion coefficient, n is number of electrons, W is scan rate, and F and R are the Faraday and Universal gas constants, respectively) from 20 to 0.001. In addition the influence of the initial potential Ei and the switching potential Eλ is included in the calculations. The dependence of the anodic and cathodic peak currents, peak potentials and half-height-full-widths on the initial potential, Ei, and the value of lnH, are described using approximate equations; the dependence of the ratio of peak currents and peak-to-peak separation on the switching potential Eλ and value of lnH, using cyclic voltammetry are also described.

New methods of stripping voltammetry with application of a mercury film electrode on a silver substrate for definition of alkaline metals, ammonium and other amines, being components of rocket fuel, are for the first time developed. These methods in a combination to methods of determination of heavy metals (Cu, Zn, Cd, Pb, Hg) are used in system of monitoring of food vegetative raw material and the agricultural production made in territory of Tomsk area.

The possibility of calculation of volt-ampere curves in reversed electrode precess on flat electrodes for any values of Н and -0 parameters without demensions characterasing the nature of electrode process, electrode parameters, form and velocity of potential change within the time compared with real time of making experiment is shown. The magnitude Н shows the affect of relationship of electrochemical reaction rate defined by velocity of potential change, diffusion conditioned by interaction between molecules in the solutions (metallic, liquid) and a square of film thickness of electrode (anode process) or electrolyte (cathode process). The magnitude -0 shows the influence of relationship of electrochemical reaction rates depending on equilibrium potential.

An exact, sufficiently simple, explicit expression is obtained and a full contour of the stripping-voltammetry peak is calculated for a reversible process on a thin-film mercury electrode of finite thickness (linear boundedly semi-infinite diffusion is taken into account) in conditions of stripping voltammetry at a linearly altering potential. That these results were obtained at all, is due to use made of two extra boundary conditions (Nemov’s and Nazarov’s). The addends in the four forms of equations derived are the limiting expressions and “corrections” in the form of Nemov’s or Nazarov’s boundary conditions. It is shown that it is advisable to employ different forms of equations at large and small values of parameter H. The peak’s height, full width at half-maximum, and potential are found to depend on H.

The full contour of a stripping-voltammetry peak for a reversible electrode process in conditions of boundedly semi-infinite and symmetrical diffusion on a thin-film mercury electrode at a linearly altering potential is calculated with an exact explicit equation allowing for the equilibrium-potential effect in a broad range of values of parameter H (which are defined by the film thickness, potential scan rate, and diffusion coefficient). The height, position of maximum, and full width at half-maximum of anodic peaks are evaluated as a function of parameter H and equilibrium potential. The latter is shown to exert substantial influence on the parameters and shape of anodic peaks.

Most rational from methods of the analysis allowing to execute of monitoring of objects of a biosphere and control, are the methods of voltammetry: classical polarography, alternating-current polarography, cyclical and stripping voltammetry. The authors propose voltammetric (VA) analysis of alkaline and alkaline earth metals (lithium, sodium, potassium, calcium, strontium) in analyzed environments (natural waters and deposits).

A rapid and sensitive technique for mercury determination by anodic stripping voltammetry is proposed. The carbon electrode modified with gold was used as an indicator electrode. The detection limit is 0.02 mu g/L for a 120 s deposition time. The influence of organic matter and inorganic interferences on the anodic stripping analysis of mercury was studied. The most popular methods of sample preparation were compared. Ozonation is the method of choice for rapid sample preparation of natural waters. For sample preparation of soil extracts the wet digestion with potassium peroxysulphate was selected. The procedure is applicable to the trace analysis of mercury(II) in different waters and soils.

A procedure was developed for determining mercury in natural water by stripping voltammetry on a gold-modified carbon electrode. The concentration dependence of the anodic stripping current of mercury is linear in the range 0.02–5 μg/L Hg(II). The interference of Fe(III), Cu(II), Cl–, Br–, I–, and F– ions with the determination of mercury was studied. Ozonation was used for rapid sample preparation. The detection limit for mercury was 0.02 μg/L at an electrolysis time of 5 min.