RESUMO
Objective:To overcome the disadvantages of bismuth removal by bismuth sulfide precipitation method recommended by existing analytical standards and improve the quality of analytical result.Methods:Based on 201×7 anion exchange resin, the experimental process of bismuth removal was designed, and verified by using spiked samples and IAEA test samples.Results:Bismuth was removed by anion exchange resin. In the removal experiments of strontium, yttrium and bismuth, the chemical recovery rate of strontium and yttrium could reach (98.6 ± 0.8)% and (98.5 ± 0.7)%, respectively, with no Bi 2S 3 precipitation found. The relative standard deviation between analytical result and theoretical values was -2.97% to 5.94%, better than 3.96%-17.8% by the standard bismuth removal method. Through validation using IAEA test samples, the relative standard deviation between the reported value and the target value for 90Sr was between 3.40%-7.09%, and all the results were acceptable. Conclusions:Bismuth could be quantitatively removed using anion exchange resin without adsorption of strontium and yttrium. In addition, the bismuth removal solution system of anion exchange resin was the same as the elution system in 90Sr analysis, and the purpose of rapid bismuth removal could be achieved without conversion system. Compared with the current standard analytical method, it was feasible and better to quantitatively remove bismuth based on anion exchange resin, which could meet the needs of routine analysis of 90Sr.
RESUMO
Objective:To compare the adsorption and desorption properties of different anion exchange resins for total ginsenosides， clarify their adsorption/desorption mechanism， and establish a simple protocol for the purification of total ginsenosides. Method:The adsorption and desorption properties of five different resins （D301， D315， D312， D330， D201） on total ginsenosides were evaluated with specific adsorption capacity， specific desorption capacity， desorption rate and recovery rate as indices. The adsorption kinetics and thermodynamics of the selected resin and D101 macroporous resin were investigated by pseudo-first-order and pseudo-second-order kinetic models， as well as Langmuir and Freundlich isothermal adsorption models， and the differences of adsorption mechanism between anion exchange resin and conventional macroporous resin were elucidated. The dynamic adsorption and desorption experiments were used to determine the optimum chromatographic parameters for anion exchange resin. After verifying the purification process of total ginsenosides， nine individual ginsenosides were qualitatively and quantitatively analyzed by liquid chromatography-mass spectrometry （LC-MS）. Result:D301 anion exchange resin was obviously superior to the other four kinds of anion exchange resin， the optimum parameters were set as follows：pH 8 of loading solution， loading volume of 2 BV， loading speed of 4 BV·h<sup>-1</sup>， eluted with 3 BV of water and 20% ethanol for the impurities， eluted with 8 BV of 80% ethanol with elution speed of 4 BV·h<sup>-1</sup>. After purified by D301 resin， the enrichment coefficients of 9 monomer ginsenosides were simultaneously increased to different degrees， the overall enrichment coefficient was up to 5.3， the recovery rate for the total amount of these ginsenosides was calculated to be 80.9%， and the purity of total ginsenosides in Ginseng Radix et Rhizoma extract increased from 17.07% to 91.19%. Conclusion:D301 anion exchange resin is suitable for rapid and practical purification of total ginsenosides， hence allowing for the enrichment of high-purity total ginsenosides from Ginseng Radix et Rhizoma via one-dimensional column chromatography.
RESUMO
Objective: To optimize the separation and purification of the total poly phenol from Dryopteris crassirhizoma with anion- exchange resin. Methods: The rates of elution and absorption, contents of dryocrassin ABBA, and total ploy phenol were used as makers to optimize the purification conditions of total ploy phenol. Results: The extracting solution of D. crassirhizoma passed through 201×7 hydrogen-oxygen the anion-exchange resin column (column diameter-column height, 1:7) at the rate of 6 BV/h in reverse direction, then the resin column was flushed with water at the rate of 6BV/h to pH value 6-7 in forward direction. At last, the column was eluted at the rate of 6 BV/h to obtain ploy phenol with 9BV 3% salt water in 60% alcohol. The elution ratio of dryocrassin ABBA is 90.1%, and the total ploy phenol is 91.1%. The content of dryocrassin ABBA is 29.4% and the content of the total ploy phenol is 49.2%. Conclusion: The separation and purification of the total ploy phenol from D. crassirhizoma with 201 × 7 hydrogen-oxygen anion-exchange resin can achieve the satisfactory results which have wide application prospects.