In this work, a novel method based on ultrasonic-assisted nebulization extraction coupled with solid phase extraction (UANE-SPE) and determined by high performance liquid chromatography was developed for the determina...
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In this work, a novel method based on ultrasonic-assisted nebulization extraction coupled with solid phase extraction (UANE-SPE) and determined by high performance liquid chromatography was developed for the determination of triterpenoids in root of Euphorbia pekinensis Rupr. The experimental conditions for the UANE-SPE, such as type of extraction solvent, sample amount, type and amount of sorbent, extraction time and volume of the elution solvent, were examined and optimized. The method was successfully applied to determine euphol and tirucallol in the dried root of E. pekinensis Rupr. The recoveries of the analytes were in the range of 89.1-102.0 %. The limits of detection were 12 mu g g(-1) for tirucallol and 10 mu g g(-1) for euphol. The extraction yields obtained by the proposed method are higher than those obtained by the conventional extraction methods, such as reflux and ultrasonic-assisted extraction. Compared with the traditional methods, the proposed method can reduce the consumption of the labor, shorten the sample preparation time and increase the efficiencies in the extraction of active constituents from plant materials.
Recently, the quality of the work of the city appearance and environmental sanitation has been constantly improved, however, the assessment of the work has not been standardized and institutionalized and the existing ...
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Recently, the quality of the work of the city appearance and environmental sanitation has been constantly improved, however, the assessment of the work has not been standardized and institutionalized and the existing professional assessment and social evaluation are certain one-sided. In that case, it is an inexorable trend to construct the multiple evaluation index system of the city appearance and environmental sanitation. This paper studies the expert evaluation index of the city appearance and environmental sanitation using Delphi method, questionnaire survey, AHP and many other methods. Moreover, it sets up an expert evaluation system of city appearance and environmental sanitation, which has good practicability and maneuverability and can reflect the development trend of the city appearance and environmental sanitation.
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