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1.
人工种植红豆杉各部位紫杉醇的提取过程分析   总被引:2,自引:0,他引:2  
对江西人工种植红豆杉叶、根、枝中紫杉醇的提取纯化技术进行了研究,比较了加热回流与超声加热回流两种提取方法,经过固相萃取、液一液萃取、正己烷沉淀、硅胶柱层析分离纯化紫杉醇,紫外扫描检测叶、根、枝中紫杉醇的含量分别13.89μg/g、12.67μg/g、39.33μg/g,纯度分别为83%、81.7%、90%,说明红豆杉植物的枝比较适合做为提取紫杉醇的原料,并且超声加热回流法优于普通加热回流法.  相似文献   

2.
三种海洋微藻抗肿瘤活性的研究   总被引:13,自引:0,他引:13  
利用不同的溶剂提取紫球藻、小球藻、等鞭金藻胞内和胞外产物,采用MTT(Methylthiazoly pheny-tetrazolium bromide)比色法检测胞内外产物对HeLa和K562肿瘤细胞活性的影响,以筛选和研究其中的抗肿瘤活性物质。结果表明:紫球藻胞外水相和破碎后上清液经石油醚:乙酸乙酯(V:V=1:1)的萃取物、小球藻破碎后上清液经乙酸乙酯、正己烷:环己烷(V:V=1:1)、三氯甲烷、甲醇:甲苯(V:V=1:1)、石油醚的萃取物和等鞭金藻破碎后上清液经石油醚、乙醚、正已烷、乙醇的萃取物都有明显的抑制肿瘤细胞的效果,显示了从海洋生物微藻中开发新的抗肿瘤药物的潜力。  相似文献   

3.
就土苻苓中4种有机磷农药的分析对比了SPE(固相萃取)与LLE(液液萃取)两种预处理技术,并对影响SPE的相关因数进行了条件优化.结果表明,优化后的SPE不仅在相同的浓度范围内有更好的线性关系,而且降低了检出下限,在准确度、精密度方面也与LLE相当.因此,用SPE—GC—FPD方法代替传统LLE检测土茯苓中有机磷农药是可行的.  相似文献   

4.
王存孝 《科技信息》2009,(27):I0033-I0033
本文就气相色谱法测定农药残留量过程中的固相萃取(SPE)、固相微萃取(SPME)、超临界流体萃取(sFE)等预处理技术作了简要的介绍.并简述了近年来了几种常见农药GC色谱检测时预处理技术的最新研究和应用情况,供从事农药残留量分析的检测与研究人员参考。  相似文献   

5.
超临界CO2流体萃取法提取紫杉醇的研究   总被引:6,自引:0,他引:6  
利用超临界CO2流体萃取法从红豆杉枝叶中提取分离紫杉醇,用反相高效液相色谱法(HPLC)测定萃取物中的紫杉醇含量,并用液质联用(LC/MS/MS)进行产物鉴定.结果表明,粒径为0.25—0.45mm的红豆杉枝叶在27.6MPa,31℃下,以甲醇为修饰剂和吸收液进行萃取时,在120min内可使紫杉醇萃取完全,萃取率达96.7%,萃取物中紫杉醇纯度可达到1%以上.与传统的乙醇三次提取方法相比,超临界流体萃取法流程简单,步骤少,耗时短,无废渣溶剂残留,是一种环境友好的提取方法.  相似文献   

6.
CO2超临界萃取芝麻油中芝麻素含量的GC-MS测定   总被引:1,自引:0,他引:1  
本文研究CO_2超临界萃取芝麻油中芝麻素含量的GC-MS测定。萃取芝麻油的最佳条件为:萃取压力32MPa、萃取温度50℃、萃取时间2h,此时萃取率达到48.5%;提取芝麻紊的最佳条件为:萃取时间3h、萃取温度60℃、料液比2.5∶1(V/V)、静止分液时间3h;最后用GC-MS技术对芝麻索进行定性和定量分析。  相似文献   

7.
山药及其同属植物参薯中多酚含量的测定   总被引:4,自引:1,他引:3  
采用Folin-Denis(FD)法和普鲁士蓝(PB)法测定山药及其同属植物参薯80%醇提物的氯仿相、乙酸乙酯相、正丁醇相中多酚含量.两种方法均显示:不同产地山药样品中,正丁醇相中多酚含量较高,乙酸乙酯相中次之,氯仿相中多酚含量最低.利用薄层层析(TLC)、紫外光谱(UV)、显色反应及^13C核磁共振(NMR)技术对各极性段萃取物进行定性检测分析,发现在氯仿和乙酸乙酯萃取部分均检测出酚性成分的存在,而在正丁醇相定性检测时,未检出酚性成分的存在.该法简便易行、重现性好、准确度高,可用于山药及其同属植物参薯中多酚含量的测定.  相似文献   

8.
高效液相色谱法测定样品中紫杉醇的含量   总被引:1,自引:0,他引:1  
建立了反相高效液相色谱法测定样品中紫杉醇含量的方法。色谱柱采用中国科学院大连化学物理研究所生产的YWQC18柱(4.6X250mm,5μm),流动相为乙腈:水:三氟乙酸(40:60:0.1),检测波长227um,紫杉醇浓度在40μg/ml~1400μg/ml内呈解性关系。回收率98.2~99.3%,变异系数0.75~3.39%。  相似文献   

9.
设计一种利用中空纤维支撑液膜萃取技术(HF-SLM)从自来水中提取四种氟喹诺酮类抗生素(氧氟沙星、依诺沙星、恩诺沙星、诺氟沙星)的简单方法:支撑液膜萃取的最适条件为:供体pH=7,受体HCl浓度为0.1mol/L,振荡时间15min,液膜构成为15%的TOPO.  相似文献   

10.
运用组合固相萃取(Solid phase extraction,SPE)柱净化、GC-ECD检测建立了6种有机氯和6种拟除虫菊酯农药残留的气相色谱同时分析方法.用乙酸乙酯作溶剂、高速均质和超声波方法辅助萃取样品中的农药残留,萃取液浓缩并转溶于丙酮-正己烷混合溶液(2:8,v/v)中,经过组合SPE柱(由上到下为CARB、SCX、bE)净化,乙酸乙酯定容.选用青花菜进行加标回收率实验,回收率为60%-120%,方法检测限为0.01μg/Kg-0.1μg/Kg.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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。  相似文献   

14.
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.  相似文献   

15.
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-  相似文献   

16.
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-  相似文献   

17.
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  相似文献   

18.
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  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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