共查询到20条相似文献，搜索用时 62 毫秒
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目的:对7个厂家生产的三黄片中大黄素和大黄酚作含量测定,考察其质量.方法:采用RP-HPLC法,以甲醇:磷酸缓冲液(9:1)为流动相,测定三黄片中大黄素和大黄酚的含量,检测波长为254nm.结果:大黄素平均回收率为99.5%,RSD为1.22%,大黄酚平均回收率为99.4%,RSD为0.66%.每片大黄素和大黄酚总量在0.31～3.16mg之间.结论:从所测得成分的含量看,7个生产厂的三黄片质量不稳定,现行标准粗略,应制定严格的质量控制标准. 相似文献
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采用C18柱(250×4.6 mm,5μm),梯度洗脱,以不同比例的乙腈-0.1%磷酸溶液为流动相,流速为1.0 m L/min,同时测定了清肺抑火片中栀子苷(238 nm)、大黄素(254 nm)、大黄酚(254 nm)的含量.栀子苷、大黄素和大黄酚分别在0.06~0.6μg、0.08~0.8μg和0.08~0.8μg范围内呈现良好的线性关系.平均回收率分别为98.33%、97.43%和97.73%;RSD值分别为0.55%、0.50%和0.87%.所建立的方法可同时测定清肺抑火片中栀子苷、大黄素、大黄酚的含量,可用于清肺抑火片的质量控制. 相似文献
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研究了用高效液相色谱法快速测定大黄中大黄素和大黄酚的含量的方法.色谱柱:安捷仑ZORBAX Stab leBound(4.6 mm×50 mm,1.8μm);流动相:甲醇-0.1%磷酸(体积比85∶15),流速0.8 mL/m in,检测波长254 nm.在该色谱条件下大黄素和大黄酚在4 m in内可达到基线分离(Rs=1.95),方法平均加标回收率为大黄素98.5%,大黄酚99.4%,RSD分别为大黄素1.47%,大黄酚0.99%,大黄素在0.04~0.12μg,大黄酚在0.08~0.24μg范围内呈现良好的线性关系,相关系数分别为r1=0.999 9和r2=0.999 9,最低检测限为大黄素0.028μg,大黄酚0.014μg.因此,该方法简便,快速,结果准确可靠,可为HPLC快速测定提供依据. 相似文献
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高效液相色谱法测定大败毒胶囊中大黄酸、大黄素及大黄酚的含量 总被引：1，自引：0，他引：1
目的：建立大败毒胶囊中大黄酸、大黄素及大黄酚的含量测定方法、方法：高效液相色谱法测定大黄的主要有效成分大黄酸、大黄素及大黄酚的含量,色谱柱为Diamonsil C18柱（250mm×4．6mm,5μm）,流动相为甲醇-0.1％磷酸（82：18）,检测波长为438nm．结果：大黄酸、大黄素及大黄酚的进样量与峰面积的线性关系良好（r分别为0．9996、0、9994和0．9993）,加样回收率分别为98.8％（RSD=0.4％）、99.6％（RSD=1．1％）和100．2％（RSD=0.9％）,结论：该法简便、准确、重现性好. 相似文献
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建立同时测定牛黄解毒片中大黄酸、大黄素、大黄酚、大黄素甲醚4种蒽醌类化合物含量的方法.用20%H2SO4水解样品,以丙酮为溶剂,索氏提取样品中的蒽醌类化合物,流动相为甲醇-0.5%磷酸水溶液(75:25,V/V),色谱柱为Kromasil C18柱,流速为1.0 mL/min,检测波长为230 nm,高效液相色谱法测定4种蒽醌类化合物的含量.样品中4种蒽醌类化合物分别在1.50~150,0.950~95.0,1.30~130,1.15~115 mg/L范围内呈良好的线形关系,测定的重复性较好,并在24 h内稳定,4种化合物加标回收率均在98.14%~101.3%之间,测定结果准确.该方法操作便捷,准确,灵敏度高,稳定性好,可用于牛黄解毒片的药物质量控制. 相似文献
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目的:建立同时测定金匮肾气片中黄芩苷和丹皮酚含量的高效液相色谱法。方法:采用C18色谱柱(4.6 mm×250 mm,5μm),以甲醇-0.1%磷酸水溶液(52:48),检测波长278 nm,柱温30℃,流速1.0 mL/min。结果:黄芩苷在0.485~19.406μg/mL,丹皮酚在1.079~43.157μg/mL线性关系良好。平均回收率(n=9)分别为99.6%,100.5%,含量测定结果表明,不同批次金匮肾气片之间黄芩苷和丹皮酚含量水平差异不大。结论:经方法学验证,该法可用于金匮肾气片中黄芩苷和丹皮酚含量的快速测定。 相似文献
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建立了一种用高效液相色谱(HPLC)荧光检测法同时测定中成药中厚朴酚与和厚朴酚含量的新方法.使用BDSC18(100mm×4.0mm,i.d.,3μm)色谱柱,流动相为乙腈0.3%-H3PO4(50∶50,V/V),荧光激发波长为220nm,发射波长为380nm.厚朴酚在0.08～246.0μg/mL范围内线性关系良好,检出限为18.4ng/mL,平均回收率为90.2%￣102.7%,日内RSD为0.80%～4.36%,日间RSD为2.18%～5.92%(n=5);和厚朴酚在0.1～231.0μg/mL范围内线性关系良好,检出限为8.7ng/mL,平均回收率为90.0%～98.1%,日内RSD为0.43%～5.53%,日间RSD为3.97%～6.50%(n=5).该法灵敏度高、选择性好、简便、易重复,为香砂养胃丸、藿香正气软胶囊、国公酒中厚朴酚与和厚朴酚的含量测定提供了有效方法. 相似文献
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《洛阳师范学院学报》2019,(2)
采用超声法提取牡丹皮中的有效成分,用高效液相色谱法测定不同产地、不同炮制方法样品中丹皮酚的含量.结果显示,相同色谱条件下,丹皮酚的平均回收率为97.30%, RSD为1.81%(n=6), 4个不同产地中陕西秦岭的丹皮样品中丹皮酚的总含量最高,而河南洛阳样品中丹皮酚的总含量最低,但各地区丹皮酚的总含量均大于1.2%.不同炮制方法提取的丹皮酚含量的比较:醋泡>生品>盐泡>蜜炒>酒泡>炒炭.结论:不同产地丹皮酚的含量有所差别,且不同炮制方法对提取的丹皮酚的含量也有影响,因此要采用合适的炮制方法,减少药效成分的破坏. 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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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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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 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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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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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献