共查询到20条相似文献，搜索用时 125 毫秒
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陆英中乌索酸的分离制备及HPLC分析(Ⅲ) 总被引：3，自引：2，他引：3
目的：分离制备陆英中的乌索酸，并建立其含量测定方法．方法：采用“醇提凝析法”分离制备乌索酸，HPLC法测定其含量，色谱柱为Symmetry Shield RP18，流动相为甲醇-水(88：12)，流速1ml／min，检测波长220nm，柱温25℃．结果：乌索酸在4．6～23．0μg范围内线性关系良好(r=0．9999)，平均回收率为99．82％(RSD为0．75％)．结论：“醇提凝析法”分离制备乌索酸工艺先进，实用可行；HPLC法测定乌索酸含量准确、可靠，可用于乌索酸含量测定分析。 相似文献
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目的:建立反相高效液相色谱法测定固体分散体中乌索酸的含量,并检测其色谱峰的纯度。方法:色谱柱为Nova-Pak C18(3.9×150 mm,4μm),流动相为甲醇-水(88∶12),流速1.0 mL/min,检测波长210nm,柱温25℃。结果:乌索酸在0.86~14.62μg范围内线性关系良好(r=0.9995),平均回收率为99.0%,检出限0.2 mg/L(3σ)。结论:方法简便,准确,重现性好,线性范围宽,适用于乌索酸制剂的质量评价。 相似文献
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目的 :建立HPLC法同时测定女宝中吴茱萸碱和吴茱萸次碱的方法。方法 :用甲醇提取女宝中吴茱萸碱和吴茱萸次碱 ,HPLC分析 ,紫外检测器检测。色谱柱 :YWG -C18(10 μm ,2 5 0mm× 4 .6mm)。流动相 :水 -甲醇 -乙腈梯度析脱。流速 :1.0ml/min。柱温 :30℃。检测波长 :2 2 5nm。结果 :吴茱萸碱的回归方程为Y =14 7.37X + 1186 .32 ,相关系数为0 .9999,线性范围为 5～ 10 0 0 μg/mL ,回收率为 99.83% ;吴茱萸次碱的回归方程为Y =10 1.19X + 2 79.81,相关系数为 0 .9999,线性范围为 4 .5～ 90 0 μg/mL ,回收率为 98.72 %。本文所用女宝胶囊中吴茱萸碱和吴茱萸次碱的含量分别为 0 .0 82 % (0 .10 3mg/粒 )和 0 .0 5 5 % (0 .0 6 9mg/粒 )。结论 :本文方法稳定性高 ,重现性好 ,操作简单。是生产女宝胶囊质量监控较理想的方法。 相似文献
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红车轴草提取物中异黄酮含量的高效液相色谱分析法的研究 总被引：4，自引：0，他引：4
边清泉 《绵阳师范学院学报》2003,22(2):52-55
建立了一种红车轴草提取物中异黄酮含量的高效液相色谱分析方法。采用日本岛津公司LC - 6AHPLC系统 ,Shim -packVP -DOS柱 (1 5 0mm× 4 6mmID ,5 μm) ,流动相MeOH -CH3 CN -H2 O(体积比 3 7∶1 3∶5 ) ,流速0 9mL·min-1 ,检测波长 2 6 0nm ,柱温 30℃ ,进样量 1 0 μL ;样品制备方法以 1 0mol L-1 HCI甲醇溶液在 85℃条件下水解 1 6h ,HPLC法测定异黄酮的含量 ;该法的RSD为 1 31 % (n =5 ) ,平均回收率为 96 5 %。 相似文献
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在AccQ·TagC18柱上,用内含0 05mol·L-1KH2PO4 H3PO4缓冲溶液的CH3OH∶H2O=40∶60(V/V)(pH=5 5)作流动相,流速为1 0ml·min-1,以紫外 可见检测器于254nm处进行检测,开发了一种RP(C18) HPLC法测定药物片剂中秋水仙碱含量的方法,并对系统的专一性和实用性进行了验证。 相似文献
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高效液相色谱测定饮料中的咖啡因 总被引：1，自引：0，他引：1
精确测定咖啡因在饮料中的含量,建立测定饮料中咖啡因含量的HPLC法的最佳工作条件.色谱柱为Hypersil ODS柱:150 mm×4.6 mm(5 μm),检测波长为270 nm;流动相A为去离子水,B为甲醇,A:B=50:50;流速1 ml/min;进样量10 μl,柱温为20℃.该方法准确、简便、快速,适合可乐型饮料中咖啡因的测定.通过优化了的色谱条件,提高了测定的精密度及线性范围. 相似文献
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乌索酸固体分散体的制备及其体外溶出度研究 总被引：1，自引：0，他引：1
目的：提高制剂中乌索酸的溶出度.方法：选择聚乙烯吡咯烷酮K30、泊洛沙姆188两种载体,用溶剂法制备乌索酸固体分散体;建立高效液相色谱-光电二极管阵列检测器法测定固体分散体的体外溶出度,并检测分析了乌索酸的峰纯度.结果：高效液相色谱法测定乌索酸的溶出度,结果准确可靠、稳定、无载体的干扰.制备的固体分散体能显著地提高乌索酸的体外溶出度;以聚乙烯吡咯烷酮为载体制备的固体分散体溶出速度快于泊洛沙姆.结论：选择聚乙烯吡咯烷酮为载体制备乌索酸固体分散体可显著提高乌索酸的体外溶出度. 相似文献
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建立了红薯中维生素C和维生素B3的检测方法.采用超声波振荡法提取红薯中的维生素C和维生素B3,利用HPLC对其进行测定,色谱柱为Hypersil ODS-C18柱,流动相为甲醇-0.025 mol/LKH2PO4溶液(pH=6.0,20:80,V/V),流速为0.9 mL/min,检测波长为200 nm.结果表明:维生素C和维生素B3在该条件下得到了较好的分离,线性范围分别为5.40~54.0 μg/mL和5.05~50.5 μg/mL,样品中的含量分别为306.7 μg/g和116.4 μg/g.该方法可用于红薯中维生素C和维生素B3含量的测定. 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献