| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to analytical chemistry and a method for quantitative determination of sterols in rhizomes with stinging nettle roots. Proposed method comprises extracting sterols from rhizomes with nettle roots with 70 % ethyl alcohol and calculating quantitative content of sterols by optical density in concentrated sulphuric acid at maximum of absorption of 328 nm in terms of ergosterol, and absolutely dry raw material in percentage (X) is calculated by formulawhere A is optical density of test solution; Ais optical density of solution of standard sample; M is accurate weighed portion of material, g; misaccurate weighed portion of ergosterol, g; W is raw material moisture content, %. In case of absence of working standard sample of ergosterol, value of specific absorption factor of its solution of 800 is used; calculation of sterol content in terms of ergosterol and absolutely dry raw material in percentage (X) is calculated by formulawhere A is optical density of test solution; m is accurate weighed portion of analysed sample, g; W is raw material moisture content, %. 800 is specific absorption factor of ergosterol.EFFECT: use of method enables high-accuracy determination of sterols in rhizomes of stinging nettle.1 cl, 2 dwg, 2 ex |
