In this work, we have prepared a miniaturized version of the standard electrochemical cell with a macro liquid/liquid interface. Instead of 5-15 mL of each phase, our design requires only 150-200 µL. Thanks to the macroscopic dimensions of the interface and a symmetric diffusion profile, the proposed miniaturized cell allows for straightforward analysis of the results and direct comparison with previous literature data. Our design presents the same advantages as a standard electrochemical cell without the disadvantages of micro-ITIES. The cell is fabricated from readily available laboratory materials, such as a glass spectrophotometric cuvette and a Pasteur pipette. Similarly to the standard cell, this design is also transparent, which allows for tracking any unusual changes at the liquid-liquid interface, such as the creation of deposits, bubbles or a microemulsion. The whole cell is contained in a spectrophotometric cuvette and can be easily adapted to spectroelectrochemical measurements. Apart from basic electrochemical performance tested for tetraalkylammonium salts solution, we have screened organoboron compounds as potential ionophores based on similarities of the liquid/liquid and solution-membrane detection mechanism in the ISE.