M.V. Shchitova

Objective. To investigate the features of the chemical and toxicological determination of 4-methoxyhydroxybenzene (4-MOHOB). Material and methods. The methods of the study were TLC, reversed-phase column chromatography of ordinary pressure, GC-MS and HPLC. 4-MOHOB was isolated from liver tissue and blood by infusion with a mixture of ethyl «acetate—acetone» (7:3). Results. The expediency of eluting the analyte from the Silasorb C18 column (150×10 mm) with the mobile phase of «acetonitrile—water» (4:6) was shown, which in combination with extraction formed the basis for the developed version of purification of 4-MOHOB extracted from biomatrices. The advantages of the «hexane—ether» (6:4) mobile phase in the identification of 4-MOHOB by TLC (Merck plates) were proven. One of the variants of 4-MOGOB identification is based on its extinction properties (UV range; medium — 95% ethanol). GC-MS (mobile phase — helium, stationary phase «5% phenyl—95% methylpolysiloxane» in a column measuring 25 m × 0.2 mm) was used as the main method of confirmatory identification of 4-MOGOB. The mass spectrum of this compound included signals of the following ions (m/z): 38, 53, 65, 81, 109, 124. A 250×4.6 mm Discovery C 18 column and an eluent of «acetonitrile—acid-water solution with a pH of 5.5» (50:50) were proposed for determining 4-MOGOB by HPLC. Conclusion. The compliance of the developed methods with the key validation parameters was confirmed. The detection limits of 4-MOHOB in 100 g of organ (liver) and blood are 0.08 and 0.06 mg, respectively, the limits of quantitative determination are 0.14 and 0.10 mg.