高效液相色谱法测定脑络通片中维生素B6的含量

采用高效液相色谱法(HPLC)测定脑络通片中维生素B6的含量.色谱柱为C18 柱(250 mm×4.6 mm,5 m),流动相:甲醇-0.01%三乙醇胺溶液(用磷酸调pH值至2.5)为1:99,检测波长291 nm.维生素B6含量测定的线性范围是10.6～95.4μg/ml,r=0.9998(n=6),回收率为99.28%,RSD=1.90%.本方法灵敏、简便、准确,可以用于脑络通片中维生素B6的含量测定.     

亚麻油中α-亚麻酸含量的测定研究

目的:建立高效液相色谱法测定亚麻油中α-亚麻酸含量的方法.方法:样品经甲酯化后用高效液相色谱法进行分析,色谱柱为AgiIent C18(4.6mm×150mm,5μm),流动相为甲醇-水(95∶5),流速1.0ml/min,检测波长210nm,柱温30℃.结果:α-亚麻酸在0.20～2.0μg范围内线性关系良好,回归方程为Y=51.73 154.71X,(r=0.999 8),加样平均回收率为99.66%,RSD为1.06%.结论:本法操作简便、准确、重现性好.     

HPLC法测定维生素口服液中烟酰胺质量浓度

采用高效液相色谱法测定维生素口服液中烟酰胺的质量浓度.色谱柱为ODS-C18柱(HypersilODS2,4.6mm×150mm,5μm),流动相为1-癸烷磺酸钠溶液(1.22→850)∶乙腈∶磷酸=850∶150∶1,流速为1.0mL/min;检测波长为280nm.烟酰胺在10～100μg/mL范围内呈良好的线性关系(r=1 0000),平均回收率为98.33%,RSD=0.66%(n=9).结果表明,本方法简便,准确,快速,灵敏度高、重现性好.     

HPLC法测定脑血栓片中丹酚酸B含量

采用高效液相色谱法测定脑血栓片中的丹酚酸B含量,利用C18色谱柱(4.6 mm×150 mm,5μm),流动相为乙睛-0.2%磷酸(21:79),流速为1.0 mL/min,检测波长λ=286 nm,柱温40℃,结果表明丹酚酸B检测浓度在0.031 76～1.985μg(Y=967.602 7X-2.419 1)范围内与峰面积值线性关系良好(r=0.999 9),平均回收率为100.39%(RSD=0.62%).本方法灵敏、简便、重现性好,结果准确,可用于脑血栓片的质量检测.     

高效液相色谱法测定当归中阿魏酸的含量

目的:建立一种高效液相色谱法测定当归中阿魏酸的含量.方法:采用高效液相色谱法,色谱柱为TIANHE C18(250 mm×4.6 mm,5μm),以甲醇-水-冰醋酸(40∶60∶0.5)为流动相,流速为1 mL/min,检测波长为320 nm.结果:阿魏酸在0.036~0.216μg范围内,线形关系良好(r=0.9999),平均回收率为101.4%(n=5),RSD为0.76%.结论:该方法测定阿魏酸含量简便、快捷、准确.     

RP-HPLC法测定美容液中水溶性维生素的含量

采用反相高效液相色谱法(RP-HPLC),同时测定美容液中水溶性维生素C,B1和叶酸的含量.ODS-C18柱(250×4.6mm.id,5μm),乙酸钠-乙酸缓冲液(pH=5.69)/甲醇(75/25,V/V)为流动相;流速1.0mL/m in;检测波长254nm.9m in内实现了良好分离,其平均回收率为97.8%~101.2%,变异系数为0.89%~1.36%.     

双波长HPLC-荧光法同时测定褪黑素和维生素B6

建立了双波长高效液相色谱-荧光检测器同时检测保健品中褪黑素和维生素B6含量的方法.考察了不同超声时间、清洗次数对保健品中褪黑素和维生素B6溶出量的影响,并对色谱条件进行了优化.采用Inertsil-100A C18色谱柱(4.6 mm×250 mm,5μm),以甲醇-水(65∶35,体积比)为流动相,流速1.0 mL/min,柱温25℃,进样量10μL.采用双波长法,0～4 min,λ_(ex)=332 nm,λ_(em)=397 nm;4 min后,λ_(ex)=286 nm,λ_(em)=352 nm.在优化的样品预处理条件、色谱条件下,维生素B6和褪黑素分别在0.1～100μg/L和1.0～1 000μg/L内线性关系良好(r≥0.998),最低检出限分别为3×10~(-3)μg/L和3×10~(-2)μg/L;定量限分别为1×10~(-2)μg/L和1×10~(-1)μg/L,平均回收率分别为99.07%和97.97%(n=3),相对标准偏差为0.04%～0.98%.本方法检测快速,灵敏,重现性较好,可用于保健品中褪黑素和维生素B6的同时测定以及市售保健品的质量控制.     

丹参颗粒剂的制备及质量考察

通过丹参颗粒剂的制备及质量考察来对比颗粒剂与其他剂型的不同与优势,并说明湿法制粒与高效液相色谱法的优点.本实验采用湿法制粒,并用高效液相色谱法对丹参酮IIA进行质量考察,色谱柱为Optimusil C_(18)(250 mm×4.6 mm,5μL),已腈-0.2%乙酸为流动相,流动速度大约为0.6 mL/min,检测波长为270 nm.丹参酮IIA在0.1 mg/m L至0.5 mg/mL的范围内呈良好的线性关系(R=0.999 6),丹参酮IIA的平均回收率为99.67%,RSD值为0.665%,3个批号的丹参颗粒剂中丹参酮IIA的平均质量比为8.305 mg/g.湿法制粒方便快捷,效果好,高效液相色谱法检测丹参酮IIA质量比重现性好,简单易行,准确可靠.     

一种泛酸钙含量的检测方法

为研究建立复合维生素B片中泛酸钙含量的测定方法,采用高效液相色谱法,C18色谱柱(150 mm×4.6 mm,5μm),以乙腈-水-磷酸(100∶900∶1)为流动相,通过在200~400 nm的波长范围内扫描,结果显示210 nm为最大吸收波长,最终确定检测波长为210 nm.结果表明,在本方法中,泛酸钙浓度在353.08~706.16μg·mL-1的质量浓度范围内,线性良好,与相应色谱峰面积呈良好的线性关系(r=0.999 4);专属性强,平均回收率为97.53%,RSD=0.89%(n=6),供试品及对照品溶液稳定性良好,常温下12 h内能保持稳定。本法准确、可靠、方便,可用于复合维生素B片中泛酸钙的含量测定及其质量控制,同时也为其他药厂同类产品的测定提供参考依据。     

HPLC法测定炎立消胶囊中原儿茶醛含量

目的:建立测定炎立消胶囊中原儿茶醛含量的方法。方法:使用高效液相色谱法,色谱柱为Diamonsil C18柱(250mm×4.6mm,5μm),检测波长280nm,0.025mol/L磷酸溶液-乙腈(93:7)为流动相。流速:1.00mL/min.。结果:在0.60μg/mL-3.0μg/mL范围内有良好的线性,平均回收率为91.05%,RSD为0.73%(n=6)。结论:该法操作简便,结果准确,灵敏度高,重现性好,可用于炎立消胶囊的质量控制。     

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.     

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the