毛细管气相色谱法测定异黄酮衍生物2702中有机溶剂残留量

建立异黄酮衍生物2702中乙醇,乙酸乙酯残留量的测定方法.采用毛细管气相色谱法,色谱柱为DB-Wax(30 m×0.45 mm×0.85 μm)石英毛细管柱;检测器为FID,载气为氮气;柱温为程序升温:起始温度为40℃,保持5 min, 然后以40℃/min的速率升至205℃,保持8 min;气化室温度为225℃.在该色谱条件下,采用甲苯为内标.测得乙醇、乙酸乙酯二种溶剂分别在1.25～87.50 μg/mL(r=0.999 8);1.80～89.90 μg/mL(r=0.999 9)范围内线性关系良好,平均回收率分别为102.0%(RSD=2.8%), 98.4%(RSD=2.3%);检测限分别为0.13 ng,0.17 ng.因此,该毛细管气相色谱法简单、结果准确,适用于本品有机溶剂残留量的测定.     

RP-HPLC法测定艾纳香中艾纳香素和二氢黄酮醇含量

采用反相高效液相色谱法测定艾纳香中的艾纳香素和二氢黄酮醇含量。确定色谱条件为:色谱柱ZORBAXXDB-C18(4.6mm×150mm,5μm),流动相为V(甲醇)¨V(水)=60¨40,流速0.8ml/min,检测波长290nm,柱温为30℃。在此条件下,艾纳香素和二氢黄酮醇与其它组分得到良好的分离,艾纳香素的线性范围为0.0032～0.048μg/μl(r=0.9999),二氢黄酮醇的线性范围为0.0032～0.048μg/μl(r=0.9993);艾纳香素和二氢黄酮醇的精密度RSD(n=5)分别为1.08%和1.26%,平均回收率(n=5)达98.36%和97.86%。     

亲水作用色谱法测定左卡尼汀注射液含量及杂质A

通过考察流动相中有机相的比例、缓冲液浓度、pH值、柱温以及流速等因素的影响,建立亲水作用色谱法测定左卡尼汀注射液含量及杂质A的方法.最终确定的色谱条件为采用XBridgeAmide色谱柱(4.6mm×250mm,3.5μm),以缓冲液(10mmol/L乙酸铵,用冰醋酸调节pH值5.0)-乙腈(20∶80)为流动相,柱温40℃,检测波长205nm.经方法学验证,左卡尼汀与杂质A分离度良好(R>1.5),左卡尼汀与杂质A浓度分别在0.530~3.21mg/mL、2.06~82.4μg/mL范围内线性关系良好,平均回收率(n=9)分别为100.4%和101.2%.杂质A检测限(S/N=3)为29.0ng/mL、定量限(S/N=10)为68.7ng/mL.结果表明该法可用于左卡尼汀注射液质量的控制.     

基于声表面波气相色谱仪的2,4,6-三硝基甲苯现场快速检测

基于声表面波气相色谱仪(GC-SAW)建立了爆炸物成分2,4,6-三硝基甲苯(TNT)的现场快速检测方法。试验条件为:检测器温度40℃;DB-5毛细管色谱柱,初始温度40℃,10℃/s程序升温至180℃。结果:TNT保留时间在9.12~9.30 s之间,最低检出限为1.89 pg,低(0.101μg/m L)、中(1.01μg/m L)、高(3.03μg/m L)浓度TNT测试的相对标准偏差分别为1.54%、2.99%和3.51%,TNT甲醇溶液在0.101~3.03μg/m L浓度范围内线性良好,线性相关系数r=0.995。用该方法对TNT未知含量样品进行检测,TNT在9.14 s时出峰,定量测试结果显示TNT未知含量样品的纯度为53.30%。建立的方法能够快速、准确地检测爆炸物成分TNT。     

HPLC法测定人参叶中人参黄酮苷的质量分数

采用高效液相色谱法,测定人参叶中的主要黄酮类成分人参黄酮苷[山柰酚-3-O-β-D-半乳糖(2→1)-β-D-葡萄糖苷]的质量分数.色谱条件:Zorbax Extend C18柱(250mm×4.6mm,5μm),流动相为V(甲醇):V(乙腈):V(体积分数为0.1%的醋酸水溶液)=25:5:70,流速为1.2mL/min,检测波长268nm,色谱柱温度为25℃.结果表明:在进样量0.5～20.0μg范围内线性关系良好,相关系数r=0.9999(n=6);人参黄酮苷的平均回收率为98.5%;RSD=0.64%(n=6)。     

高效液相色谱法测定乳制品中三聚氰胺的含量

为建立乳制品中三聚氰胺含量的高效液相色谱测定方法,通过超声提取,离子交换萃取小柱净化,结合高效液相色谱进行样品测定.色谱条件:Eclipse XDB-C18柱(5μm,4.6 mm×150 mm,Agi-lent);流动相:A为离子对缓冲液(1.05 g柠檬酸和1.01 g辛烷磺酸钠定容至500 mL,pH值为2.6),B为乙腈,配制比例为90%A+10%B,流速1.0 mL/min,柱温30℃,进样量20μL,检测波长240 nm.结果表明:三聚氰胺标准曲线为y=0.009x+0.362 7,相关系数R=0.999 8,在0.17~110.0 mg/L范围内线性关系良好,方法检出限为0.12 mg/L,两个样品三个水平的加标回收率分别为96.34%(RSD=4.76)、84.86%(RSD=7.21)、104.29%(RSD=7.63)和95.31%(RSD=4.39)、89.25%(RSD=3.88)、92.59%(RSD=5.27).     

鬼灯檠属及近缘植物中岩白菜素的HPLC定量分析

目的:比较鬼灯檠属及近缘植物中岩白菜素的含量,为资源利用提供依据.方法:色谱条件采用ZORBAX SB-C18色谱柱(4.6mm×150mm,5μm),流动相为甲醇-水(含0.1%磷酸)17:83,检测波长275nm,流速0.80ml/min,柱温30℃.结果:岩白菜素线性范围在3.05～10.98μg范围内呈良好的线性关系,r=0.999 91,平均回收率为101.17%(n=5),s=1.56%.结论:本次实验说明这些在民间作为岩陀使用的植物中都含有岩白菜素,且种间差异大.     

RP-HPLC法同时测定菥蓂药材中7种黄酮苷的含量

建立了一种可以对菥蓂药材中5,7-二羟基-4'-O-(6″-O-β-D-葡萄糖)-β-D-葡萄糖黄酮、异肥皂草苷、异荭草苷、牡荆苷、异牡荆苷、木犀草苷和大波斯菊苷的含量进行同时测定的RP-HPLC法。色谱条件:色谱柱为Agilent C18柱(4.6×150 mm,3.5μm);流动相为乙腈-0.4%冰醋酸水溶液,梯度洗脱;流速1.0 m L/min;检测波长273 nm;柱温35℃。结果表明,在上述色谱条件下,5,7-二羟基-4'-O-(6″-O-β-D-葡萄糖)-β-D-葡萄糖黄酮、异肥皂草苷、异荭草苷、牡荆苷、异牡荆苷、木犀草苷和大波斯菊苷的质量浓度分别在5.67~56.7μg/m L(r=0.999 7),10.92~109.2μg/m L(r=0.999 4),5.76~57.6μg/m L(r=0.9998),4.92~49.2μg/m L(r=0.999 8),13.95~139.5μg/m L(r=0.999 9),5.25~52.5μg/m L(r=0.999 8),5.22~52.2μg/m L(r=0.999 7)范围内与色谱峰的峰面积呈现良好的线性关系,平均加样回收率均在97%~101%,RSD均小于2.7%。该分析方法简便、快速、准确且重现性好,为有效地监控菥蓂药材的质量提供了可靠方法。     

高效液相色谱法测定鞣柳硼三酸散中水杨酸含量

通过采用高效液相色谱法,建立了对鞣柳硼三酸散中水杨酸的含量测定方法。以Agilent SB-C18色谱柱(250mm×4.6mm,5μm),甲醇-0.4%磷酸溶液(60∶40)为流动相,检测波长305nm,流速1.0m L/min,25℃柱温,在此优化的条件下,水杨酸在0.063 44~1.268 8μg之间线性关系良好(r=1.000 0,n=5),回收率为101.26%,RSD为0.48%(n=9)。该方法简便、准确,可用于鞣柳硼三酸散中水杨酸的含量测定,对控制制剂质量有一定指导意义。     

高效液相色谱法检测鸡蛋中的三聚氰胺

建立了高效液相色谱法检测鸡蛋中三聚氰胺的方法。样品用1%三氯乙酸和2.2%乙酸铅超声提取。色谱柱为HypersilODS100×4.6mm,5μm;流动相为乙腈:辛烷磺酸钠离子对试剂(pH=3)=15:85(V/V);流速为1mL/min;检测波长为210nm;柱温为40℃。三聚氰胺在0.2μg/mL～10μg/mL范围内,有良好的线性关系。在空白样品中添加0.2μg/mL、0.4μg/mL、1.0μg/mL三个质量浓度的标准工作液,回收率在82.0%～104.0%,相对标准偏差为6.81%(n=9)。     

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