Study of Threonine Extraction by N-Vinylformamide Based Copolymers

New extraction systems based on N-vinylformamide for the extraction of threonine for its subsequent determination in aqueous media are proposed. Such systems meet the requirements of "green" chemistry, are non-toxic, non-flammable, and are capable of providing almost complete extraction of threonine. The interphase distribution of threonine in systems with poly-N-vinylformamide, copolymers of N-vinylformamide with N-vinylimidazole, 1-vinyl-3,5-dimethylpyrazole, 1-methacryloyl-3,5-dimethylpyrazole was studied. The article presents the calculated distribution coefficients and the degree of extraction of threonine in the concentration range of 1.0 - 3.0 mg/cm3. The influence of the extractant concentration, the nature of the salting out agent, the ratio of the volumes of the aqueous and organic phases, the time and temperature of extraction on the quantitative characteristics of the interphase distribution was studied. Optimum extraction conditions have been established, at which the degree of threonine extraction by N-vinylformamide copolymers reaches 97%: extractant is a copolymer of N-vinylformamide with 1-methacryloyl-3,5-dimethylpyrazole with a concentration of 0.25 mol/dm3, phase ratio is 10:3, threonine concentration is 2.5 - 3.0 mg/cm3. The advantages of extraction by N-vinylformamide copolymers were shown in comparison with other polymers. Determination of threonine in the aqueous phase after extraction is carried out by capillary electrophoresis at a wavelength of 254 nm. The results of electrophoretic determination of the amino acid are processed using the Elforan software for Windows. Schemes of interphase interaction in the poly-N-vinylformamide – threonine system due to the formation of hydrogen bonds are proposed, taking into account the features of the properties and structure of the extractant and analyte. The developed method of extraction-electrophoretic determination of threonine in aqueous media can be recommended for assessing the quality of food products and protein mixtures. For citation: Mokshina N.Ya., Pakhomova O.A., Ivanchura P.V. Study of threonine extraction by N-vinylformamide based copolymers. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 10. P. 58-63. DOI: 10.6060/ivkkt.20256810.7207.