HPLC测定冷浸法提取中成药中的甘草酸含量

报道了以 PC8为色谱柱 ,甲醇 :水 :醋酸 (5 7.0∶ 42 .6∶ 0 .4,V∶ V∶ V)为流动相 ,在 UV2 5 4nm为测定波长的条件下 ,利用外标法定量 ,建立了反相高效液相色谱法测定冷浸法提取自制的 (依据经典成方 ) 8种方剂和 12种市售中成药中甘草酸含量。实验表明 ,本法操作简便、快速、结果准确 ,适用于测定不同类型制剂中甘草酸的含量。     

高效液相色谱法测定安脑牛黄胶囊中栀子苷含量

目的　建立安脑牛黄胶囊中栀子苷含量测定方法 .方法　采用C1 8柱 ,以乙腈 -水 (1 0∶90 )为流动相 ,检测波长为 2 38nm .结果　线性范围为 0 .1 6～ 0 .80 μg ,回收率为 99.2 5 % ,RSD为 1 .30 % .结论　该方法简便易行 ,可供安脑牛黄胶囊中栀子苷质量控制     

高效液相色谱法检测红发夫酵母胞内虾青素

确定了红发夫酵母的破壁提取方法并采用高效液相色谱法定量地测定了红发夫酵母胞内虾青素的含量。试验得到的液相色谱条件为:色谱柱KromasilC18, 5μm, 250mm×4. 6mm;流动相为甲醇和乙腈,V甲醇∶V乙腈=9∶1;流速1. 4mL/min;检测波长478nm;柱温为室温。加标回收率为(98. 2~102. 8)00。     

槲皮素的阳极伏安行为研究

研究了槲皮素在玻碳电极上的阳极伏安行为 .在pH =5 .8的Na2 B4O7(0 .0 5mol L) -NaH2 PO4(0 .1mol L)缓冲溶液中 ,槲皮素于 +0 .2 0V(vs .SCE)左右产生一个灵敏的阳极氧化峰 ,其浓度与峰电流在 8.0× 10 - 8- 1.0× 10 - 4 mol L范围内呈良好线性关系 ,检测限为 2 .6× 10 - 8mol L .用本法不需分离直接测定了模拟血清中的槲皮素 ,相对标准偏差为 2 .1%,回收率为 98.5 %.     

HPLC法测定双黄连片中绿原酸的质量分数

探讨高效液相色谱法测定双黄连片中绿原酸含量的方法 ,控制其质量 .Shim -packVP -ODS(4 6mm× 15 0mm ,5 μm)色谱柱 ,流动相为甲醇 -水 -冰醋酸 (2 0∶80∶1) ,流速为 1 0mL/min ,检测波长为 32 7nm .绿原酸在 0 4 0 8～ 2 0 4 0 μg范围内呈良好的线性关系 ,回归方程为A =2 84 0 95 98C +6 894(r=1.0 0 0 ) ,平均回收率为 10 0 .98% (RSD为 1.13% ) ,重复性RSD为 0 .32 % .方法简便、快速、灵敏、准确、重现性好 ,可作为双黄连片中绿原酸的质量控制标准     

高效液相色谱法测定柯柯豆碱母液中柯柯豆碱、咖啡因的含量

控制提取工艺需要测定柯柯豆碱母液中柯柯豆碱、咖啡因的含量。采用高效液相色谱法测定柯柯豆碱母液中柯柯豆碱、咖啡因的含量 ,以 C8柱为色谱柱 ,以 V(体积分数为 0 .0 0 4 5 %的高氯酸 )∶ V(乙腈 ) =80∶ 2 0为流动相 ,检测波长为 2 80 nm,柯柯豆碱与咖啡因色谱峰的分离度大于 4 ,线性范围为 10～ 80μg/ m L ,相关系数大于0 .999,回收率大于 99.0 %。     

反相高效液相色谱法测定三白草中槲皮素和芦丁的含量

采用反相高效液相色谱法 (RP -HPLC)在C1 8色谱柱上以甲醇 :0 .2 %磷酸溶液 (5 0∶5 0 )为流动相测定了三白草中槲皮素和芦丁的含量 .流动相的流速为 1mL min ,检测波长 370nm .结果表明槲皮素在 0 .0 0 8-0 0 84 μg、芦丁在 0 .0 5 4 - 0 .5 4 0 μg范围内呈良好的线性关系 ,相关系数分别为 0 .9988和 0 .9999.槲皮素回收率为 99% ,RSD为 2 .0 % (n =5 ) ,芦丁为 10 6 % ,RSD为 1.4 % (n =5 ) .     

HPLC法测定蒙药地格达—4味汤中栀子苷的含量

运用HPLC建立蒙药“地格达— 4味汤”中栀子苷含量的方法 .采用C18柱 ,乙腈一水 (15∶85 )为流动相 ,流速 1 0ml/min ,检测波长 2 38nm .结果该法平均回收率 99 1% ,RSD =1 78% (n =5 ) .该方法简便 ,快速 ,准确 ,为测定蒙药地格达— 4味汤中栀子苷含量提供了可靠的方法     

反相液相色谱法测定维生素D_2微粒胶囊

采用反相高效液相色谱法测定维生素D2 微粒胶囊中VD2 的含量。用AlltechC18柱 ( 1 5 0mm× 4 6mmID ,3μm) ,流速为 1 0mL·min- 1,流动相为V(甲醇 )∶V(水 ) =90∶1 0 ,以苯并 [e]芘为内标 ,UV2 6 5nm检测 ,本法简便、准确、重现性好[1] [2 ] 。     

一种测定工业废水中Hg^2＋的新方法

研究了碱性染料亚甲基蓝 (MB)同 KBr与 Hg2 络合形成的稳定络合物用于分光光度法测定 Hg2 的方法。在柠檬酸 -硫酸缓冲介质 p H=3 .8的条件下 ,络和物的最大吸收波长λmax=6 5 7nm,表观摩尔吸光系数 ε=1 .0 6× 1 0 5L· mol- 1· cm- 1 ,该络和物的组成为 n(Hg2 )∶ n(Br- )∶ n(MB) =1∶ 3∶ 1 ,线形范围为 0 .0 1 8～ 0 .80 0 μg·m L- 1。具有灵敏度高、稳定性好的特点。并对实际水样进行了测定 ,结果可靠。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that