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HPLC测定小儿清肺止咳片中葛根素的含量 总被引：1，自引：0，他引：1
建立了HPLC法测定小儿清肺止咳片中葛根素含量的方法.样品中的葛根素以50%乙醇为溶剂,超声提取15min.在Shim-pack VP-ODS(250mm×4.6mm,5μm)色谱柱上,以甲醇-水(30:70)为流动相,检测波长:250nm的条件下,测定葛根素的线性范围为1.0～50.0mg·L-1,线性相关系数r=0.9999,检出限为0.017mg·L-1,平均回收率为98.80%,RSD为3.48%(N=5).此法简单、快速,结果准确、可靠、重现性好.可对药品中葛根素含量的测定提供参考. 相似文献
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建立测定复方碘化钾滴眼液中维生素C含量的高效液相色谱法。采用Diamonsil C18柱(250 mm×4.6 mm,5μm),以0.05 mol·L-1磷酸二氢钾溶液为流动相,检测波长为266 nm,柱温为20℃,样品用0.01 mol·L-1盐酸溶液稀释25倍,进样40μL。结果表明,维生素C的线性范围为4.056~40.56μg·mL-1,平均回收率为99.58%,RSD=1.22%。可见本方法操作简便,快速,结果准确。 相似文献
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在pH=8.89,NH3·H2O—NH4Cl底液中,用单扫描示波极谱法,进行常规极谱测定,锌在-1.33V(vs.SCE)产生一尖锐灵敏的极谱波,峰电流与锌的浓度在2.0×10-6mol·L-1～7.0×10-4mol·L-1范围内呈良好的线性关系,检出限为1.0×10-6mol·L-1.线性回归方程为Ip=18.12x+226.5,x为锌的浓度,相关系数r=0.9991。测定金施尔康中锌的标准加入回收率可达98.8%～101.1%,结果令人满意。 相似文献
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催化动力学极谱法测定铬(Ⅵ)的研究 总被引：2，自引：0，他引：2
在0 01mol·L-1H2SO4介质中,铬(Ⅵ)对溴酸钾氧化甲基橙的反应具有强烈的催化作用,甲基橙于-0 59V处产生一灵敏的导数极谱波,以极谱法测定催化反应过程中甲基橙浓度的变化,建立了测定痕量铬(Ⅵ)的催化动力学新方法。该方法的线性范围为8 0×10-4～3 6×10-2mg·L-1,检出限为1 25×10-7mg·L-1,应用于电镀废水中痕量铬(Ⅵ)的测定,结果令人满意。 相似文献
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目的：建立同时测定盐酸特比萘芬压敏胶贴剂中酮康唑和盐酸特比萘芬含量的高效液相色谱法。方法：色谱柱为Thermo ODS-2 Hypersil柱（4.6mm×250mm,5μm）,流动相为甲醇-0.03mol·L-1醋酸铵溶液（84：16）,流速为1.0m L·min-1,检测波长为244nm,柱温为室温。结果：酮康唑和盐酸特比萘芬的浓度分别在8.160~81.60μg·m L-1（r=0.9996）和31.30~313.0μg·m L-1（r=0.9997）范围内与峰面积呈良好的线性关系;平均回收率分别为100.0%和99.3%,RSD分别为2.2%和2.5%。结论：本方法快速简便,重复性好,专属性强,可作为盐酸特比萘芬压敏胶贴剂的质量控制方法之一。 相似文献
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HPLC测定不同品种鱼腥草中绿原酸的含量 总被引：1，自引：0，他引：1
建立HPLE测定不同品种鱼腥草中绿原酸含量的方法,采用DiamonsilTMC18(4.6mm×150mm,5μm)为色谱柱,0.05mol.L-1NaH12PO4-MeOH(7.3:2.7)为流动相,流速为1mL·min-1,检测波长为326nm.结果如下:绿原酸线性范围为0.092-0.552μg,平均回收率97.7%,RSD为3.1%;结论:该方法简便、准确、重现性好.可供鱼腥草原料选择和制剂质量控制的参考. 相似文献
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应用线性扫描极谱法和循环伏安法对美洛昔康的极谱行为进行了研究.在0.08mol·L-1HAc-NaAc(pH4.5)支持电解质中,美洛昔康于-1.20V(vs.SCE)处产生一灵敏的极谱催化氢波,其二阶导数峰峰电流与美洛昔康浓度在2.0×10-8～1.6×10-6mol·L-1范围内呈线性关系(r=0.9996,n=8),检测限为1.0×10-8mol·L-1.10次测定1.0×10-6mol·L-1美洛昔康峰电流相对标准偏差RSD为0.6%,回收率在92.6%～101.2%之间.该方法可用于药剂中美洛昔康的测定.本文对美洛昔康的反应机理进行了探讨. 相似文献
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《赤峰学院学报(自然科学版)》2016,(17)
研究了以小颗粒氢醌氧化还原树脂为还原柱,在线还原Cr(Ⅵ)为Cr(Ⅲ),以鲁米诺-过氧化氢体系流动注射化学发光同时测定Cr(Ⅵ)和Cr(Ⅲ)的方法.方法简单,快速,Cr(Ⅲ)的检出限为4.0×10-10g·m L-1;Cr(Ⅵ)的检出限为6.2×10-10g·m L-1.Cr(Ⅲ)和Cr(Ⅵ)的线性范围为1.0×10-9~5.0×10-7g·m L-1.测定结果与标准方法无显著性差异.还原柱至少可供2000次测量. 相似文献
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建立RP-HPLC法测定金鹃叶中芸香甙的含量.采用shim-pack CLC-ODS柱(6.0mm×250mm,5μm),以MeOH-H2O-HAc(45.50.5)为流动相,256nm波长,测定金鹃叶中芸香甙的含量.待测组分与其它组分分离效果良好(R＞1.5),平均回去收率为98.9%,该方法的RSD为2.86%(n=5),该方法操作简单,结果可靠. 相似文献
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示波极谱法连续测定太湖流域大米中锌、铁、锰、铜、铅、镉含量 总被引：1，自引：0，他引：1
研究了示波极谱法在三乙醇胺-乙二胺-硫氰酸钾-乙酸-盐酸-碘化钾-十二烷基硫酸钠体系中连续测定太湖流域大米试样中锌、铁、锰、铜、铅、镉六种微量元素.在该体系中,六种微量元素分别在-1425mV、-1638mV、-1717mV、-508mV、-533mV、-668mV产生稳定的二阶导数极谱波.锌、铁、锰、铜和铅最低检出限为0.01μg·mL-1,镉最低检出限为0.005μg·mL-1,锌、铁、铜、铅的浓度在0.01～0.80μg·mL-1,镉在0.005～0.80μg·mL-1,锰在0.01～0.50μg·mL-1范围内与极谱波峰高成正比.六种微量元素回收率范围:94.4%～103.5%,RSD:0.14%～8.72%.该方法操作简便,灵敏度和精确度高.该方法应用于太湖流域18种大米中六种微量元素的测定,与原子吸收分光光度法测得的结果基本一致. 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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《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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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
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献