The widespread use of aromatic acids (benzoic acid, salicylic) as preservatives necessitates their qualitative and quantitative determination in food. Effective and common way to separation and concentration of aromatic acids liquid extraction. Biphasic system of water-soluble polymers based on (poly-N-vinyl pyrrolidone, and poly-N-vinylcaprolactam) satisfy the requirements of the extraction system. When sorption concentration improved definition of the metrological characteristics, comply with the requirements for sensitivity and selectivity definition appears possible, use of inexpensive and readily available analytical equipment. When studying the adsorption of benzoic acid used as a sorbent crosslinked polymer based on N-vinyl pyrrolidone, obtained by radical polymerisation of a functional monomer and crosslinker. In the extraction of benzoic acid to maximize the allocation of water and the organic phase of the polymer used salt solutions with concentrations close to saturation. Regardless of the nature of the anion salt is used as salting-out agent, aromatic acids sorption increases with the size of the cations. In the experiment the maximum recovery rate (80%) benzoic acid obtained in the PVP (0.2 weight%.) Ammonium sulphate. The dependence stepepni benzoic acid extraction from time sorption sorbent mass and the pH of the aqueous phase. To establish equilibrium in the system, for 20 minutes. The dependence of the degree of extraction of the acid pH indicates that the acid is extracted into the molecular form. The maximum adsorption is reached at pH 3,5, with its efficiency decreases symbatically reduce the amount of undissociated acid molecules in solution.

benzoicacid, sorption, extraction, N-vinylpyrrolidone, N-vinylcaprolactam

1. Zolotov Yu.A. Osnovy analiticheskoi khimii. Osnovnye voprosy. Metody razdeleniya [Fundamentals of Analytical Chemistry. General issues. Separation methods. Volume 1]. Moscow: Vysshaya shkola, 1999. 351 p. (In Russ.).

2. Dmitrienko S.G., Apyari V.V. Penopoliuretany. Sorbtsionnye svoistva i primenenie v khimicheskom analize [Polyurethane foams. Sorption properties and applications in chemical analysis]. Moscow, KRASAND, 2009. 264 p. (In Russ.).

3. Sukhanov P.T. et al. Sorption of phenol and cresol from aqueous solutions of cross-linked polymers based on N-vinylpyrrolidone. Sorbtsionnye i khromatograficheskie protsessy. [Sorption and chromatographic processes], 2012, vol. 12, no. 5, pp. 712-717. (In Russ.).

4. Sukhanov P.T., Korenman Ya.I. Kontsentrirovanie i opredelenie fenolov [Concentration and determination of phenols]. Voronezh: VGTA, 2005. 260 p. (In Russ.).

5. Danilov V.N., Korenman Ya.I. Study patterns of extraction hydroxyechinenone-sibenzoynyh acid. Materialy IV Mezhdunar. konf. “EOS-2010” [Proceedings of IV International. Conf. "EOS-2010"]. Voronezh, 2010. pp. 40. (In Russ.).

6. Safiulina A.M., Rosen A.M., Sinegribova O.A., Shkinev V.M. Questions phase formation in the systems of water-soluble polymer-inorganic salt. Sovremennye problem khimii i tekhnologii ekstraktsii. [Modern problems of chemistry and technology of extraction], 1999, vol. II, pp. 204-205. (In Russ.).

7. Korenman Ya.I. Extraction concentration of benzoic acid hydrophilic solvents. Materialy mezhdunar. konf. “EOS” [Mater. Intern. Conf .. "Extraction organic compounds"]. Voronezh, 2000, vol. 2, pp. 39 47. (In Russ.).

8. Churilina E.V., Shatalov G.V. Polimery na osnove N-vinilkaprolaktama [Polymers based on N-vinyl caprolactam]. Voronezh: VGUIT, 2011. 171 p. (In Russ.).

9. Churilina E.V., Sukhanov P.T., ErmakS.S., Korenman Ya.I. et al. New polymers based on N-vinilamidovdlya con-centering nitrophenols from aqueous media. Zhurnal analitiches koikhimii. [Journal of Analytical Chemistry], 2012, vol. 67, no. 9, pp. 855-859. (In Russ.).

10. Churilina E.V., Sukhanov P.T., Korenman Ya.I., Il’in A.N. Two-phase systems based on poly-N-vinyl caprolactam for extraction concentration of phenols from aqueous solutions. Vestnik VGUIT. [Bulletin of VSUET], 2012, no. 1, pp. 112-114. (In Russ.).

11. GOST 28467-90 11 Produkty pererabotki plodov i ovoshcjei. Metod opredeleniya benzoinoi kisloty [Products of fruits and vegetables. Method for determination of benzoic acid]. (In Russ.).

12. Churilina E.V., Kushnir A.A., Sukhanov P.T., Mastyukova T.V. Influence of temperature and salting-out agents on the sorption of nitrophenols from aqueous solutions. Vestnik VGUIT. [Bulletin of VSUET], 2013, no. 2 (56), pp. 160-163. (In Russ.).