Synthetic food colorings (SPK) are widely used to impart consumer properties to food. But. many of them are allergens. Therefore, their definition in food objects is relevant. The rapid method of determining the SPK is ionometry. It is based on the use of ion- selective electrodes. Such an electrode for determining the food coloring E133 is not described in the literature. The purpose of this work is the study of the ionophore. Used to determine the E133 in a variety of food products. The objectives of this study were to establish the conditions for the formation of the dye associate E133 with cetiperidinium cations (SP). Evaluation of the composition of the associate and the size of the cysts with its formation in time. For this, the following methods were used: NMR spectroscopy, elemental analysis, turbidity spectrum method. The presence of a cation of CP and E133 is established in the composition. The gross of the forum of associate E133 (CP) 2.It is shown that the particles of the precipitated asocyanate have an average size of 95 nm. Aggregation of particles within an hour increases their size to 220 nm. In excess of the CPU, the precipitate is soluble. The sediment is stable up to 100 С.