| 摘要 |
FIELD: chemistry.SUBSTANCE: method of extracting theobromine from aqueous solutions involves preparation of an aqueous salt solution of theobromine via dissolution thereof in a saturated solution of a salting-out agent, extraction and analysis of the equilibrium aqueous phase, where theobromine is extracted with a solution of a solvotropic reagent, specifically dioctyl phthalate in an ethyl acetate/chloroform mixture (0.2:0.8 mole fractions, respectively) with concentration of 0.85-0.90 mol/dmfor 7-10 minutes from the aqueous salt solution of theobromine, having pH 4.3±0.5. The ratio of the volume of the aqueous salt solution of theobromine to that of the extractant is equal to 10:1; the salting-out agent used is ammonium sulphate solution. Further, the water-salt phase is separated from the organic phase and analysis is carried out via UV spectrophotometry at wavelength of 272 nm; concentration of theobromine in the analysed aqueous solution is determined from a calibration curve, and the distribution coefficient (D) and degree of extraction of theobromine (R, %) are calculated using formulae.EFFECT: method of extracting theobromine from aqueous solutions is characterised by rapidness and enables to achieve virtually full extraction of theobromine from an aqueous salt solution.1 ex |
