ИСТИНА

Voltammetry (VA) at the interface of two immiscible electrolyte solutions (ITIES) is a high-precision and fast electrochemical analysis method [1]. Previously, the practical use of VA on ITIES for electrochemical analysis was mainly theoretical due to the difficulty of stabilizing the electrolyte-electrolyte interface. One solution to this problem is to use a microperforated membrane. This paper considers the use of polyethylene terephthalate (PET) film membranes with a thickness of 10 microns, one of which is perforated with a laser (membrane I), and the other with a microneedle punch (membrane II). Electrochemical sensors have been created based on these membranes. Significant ions such as ClO4-, ReO4- in aqueous solutions have already been quantified using the developed membrane I sensor [2]. In this work, using membrane II, TcO4- in an aqueous solution was quantified for the first time by cyclic voltammetry at micro-ITIES. The measurements were carried out in cyclic (Fig. 1) and square-wave voltammetry according to a 4-electrode measuring circuit. Thermodynamic characteristics such as formal Gibbs free energy of ion transfer (16.4 kJ mol-1 ), potential of simple ion transfer (-0.169 V), and diffusion coefficient (4.5·10-6 cm2·s-1) are calculated based on the obtained voltage curves. This work was supported bу the Ministry of Science and Higher Education of the Russian Federation.