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1.
《河南科学》2017,(9):1406-1411
为了建立并验证一个液相色谱串联三重四级杆质谱法(LC-MS/MS)测定药材中的川楝素,供试品经甲醇水浴回流提取后,采用Agilent Eclipse Plus C18色谱柱(4.6 mm×100 mm,3.5μm),以乙腈-0.01%甲酸水溶液为流动相梯度洗脱,流速为0.5 mL/min,柱温30℃,进样量2μL.质谱条件为电喷雾电离源(ESI),负离子模式,选择离子监测(SIM),用于定量的离子为573.1.结果显示,川楝素在42.73~2 136.40 ng/mL范围内线性关系良好(R2=0.999 6),加样回收率为99.34%~106.53%,日内、日间精密度(RSD)均低于3%,最低检出限(LOD)为0.92 mg/kg,最低定量限(LOQ)为3.05 mg/kg,稳定性较好.说明所建方法能够高效快捷地对川楝素进行测定,且方法简便、专属性强、灵敏度高,测定结果准确可靠,适用于川楝子、苦楝皮中川楝素的定性定量测定,也为其新制剂的设计和开发提供方法参考.  相似文献   

2.
目的:建立高效液相色谱法测定蒜油中的大蒜素含量。方法:蒜油样品经正己烷溶液溶解,采用C18色谱柱(4.6mm×250mm,5um),以乙腈∶水∶四氢呋喃(68∶30∶2)为流动相,流速1.0mL/min,柱温:25℃,用紫外检测器在225nm波长下测定蒜油中大蒜素含量。结果:大蒜素在16.0~80.0ug/mL质量浓度范围内具有良好线性关系(r=0.9998),最低检出限为2ng/mL,在低、中、高3个水平下的加标回收率为98.4%~99.1%,相对标准偏差(RSD%)为0.29%~0.73%。结论:该方法前处理操作简便、灵敏度高、适用范围广。  相似文献   

3.
基于牛血清蛋白在高良姜素-高锰酸钾-多聚磷酸体系中的化学发光反应,结合流动注射技术,本文首次建立了测定牛血清蛋白的流动注射-化学发光(FI-CL)新方法.在优化条件下, 化学发光强度ICL与牛血清蛋白的浓度在0.08~100 μg/mL范围内呈良好线性关系,回归方程为ICL=220.448 7.068C(r=0.999 7,n=9),检出限为0.01 μg/mL(3σ).对1.0 μg/mL的牛血清蛋白标准溶液进行11次平行测定,相对标准偏差为1.5%.该方法简单、快速、灵敏,用于合成样的测定,回收率在98.5%~100.2 %之间.  相似文献   

4.
流动注射化学发光法测定芹菜素   总被引:1,自引:0,他引:1  
在硝酸介质中,罗丹明6G可增强Ce(Ⅳ)氧化芹菜素的微弱化学发光,据此建立了测定芹菜素的化学发光新方法,在优化条件下,该法测定芹菜素的线性范围为5×10-10~2×10-7g/mL,检出限为0.2-ng/mL;相对标准偏差(c=2×10-7g/mL,n=11)为3.0%.将本法用于芹菜提取物中芹菜素的测定,获得满意结果.  相似文献   

5.
RP-HPLC直接测定水果中维生素C含量   总被引:2,自引:0,他引:2  
应用反相高效液相色谱法对时令水果中维生素C含量进行直接测定.方法: 色谱柱Eclipse XDB-C18 (5 μm 4.6×250 mm);流动相乙腈-水(40∶ 60 v/v);流速1.0 mL/min;检测波长275 nm.实验结果表明维生素C在(10 ~ 640) μg/mL范围内呈良好线性,R2=0.999 96,回收率为99.3% ~ 104.5%,RSD=1.65%.本法操作简便,结果准确、重现性好,为测定水果中维生素C的含量提供了一种有效方法.  相似文献   

6.
建立重组人白细胞介素2中乙腈残留量的顶空气相色谱测定方法.采用聚乙二醇20000石英毛细管柱(30 m×0.25 mm×0.25 μm), 高纯氮为载气,顶空进样,氢火焰离子化检测器(FID)检测.乙腈在1.014 ~5.070 μg/mL的质量浓度范围内呈良好的线性关系 ( 相关系数r为0. 997 3),平均回收率为97.2 %(相对标准偏差RSD为2.8%),乙腈的最小检测限为0.6 μg/mL.所用方法简便、灵敏度高、重复性好,可用于重组人白细胞介素2中乙腈残留量的测定.  相似文献   

7.
建立了固相萃取-毛细管电泳联用测定河水水样中四环素类抗生素残留的分析方法.以有序介孔炭(OMC)作为固相萃取吸附剂,考察了有序介孔炭对四环素类抗生素(四环素、土霉素和多西环素)的吸附性能,探讨了影响固相萃取效率的因素,得到最佳萃取条件为:水样2.00 mL(pH 10.0),有序介孔炭5.0 mg,V(甲醇)∶V(乙腈)=1∶1的洗脱液4.00 mL,洗脱速度0.7 mL/min,此时富集倍数达50倍.在最佳的毛细管电泳分离条件下,各组分含量在3 000~11 000μg/L呈良好的线性关系,且各组分峰面积的日内相对标准偏差低于8.5%(n=5).四环素、土霉素和多西环素的最低检测限和平均回收率分别为1.96~2.14μg/mL和46.7%~93.6%.研究表明,有序介孔炭可作为环境样品中多西环素和土霉素的高效吸附材料.  相似文献   

8.
建立了新的高效液相色谱-紫外检测方法对两种抗癫痫药物地西泮(DP)和卡马西平(CBZ)进行同时测定。以乙腈-0.01mol/LKH2PO4(40∶60,v/v)为流动相,流速为0.4mL/min,紫外检测波长216nm时,使用Diam-oncil C18柱对两种药物能够达到很好的基线分离。两种药物的回收率在95%~104%之间,DP和CBZ的检测限分别为6ng/mL和15ng/mL。分别对0.5μg/mL的DP和CBZ进行了11次平行测定,其日内RSD对应为2.2%和1.4%。本方法灵敏、准确,已用于对儿童尿液中的DP和CBZ进行的定性及定量分析,并获得满意结果。  相似文献   

9.
建立了用反相高效液相色谱法测定肉牛组织中磺胺二甲基嘧啶杀菌剂残留量的方法.色谱条件是:Shimpack VP-ODS 250 L×4.6色谱柱,V(甲醇)∶ V(乙腈):V(2%乙酸)=15:15:70的溶液为流动相,流速为0.6mL/min,检测波长为270 nm.结果表明磺胺二甲基嘧啶能较好地分离,在4.0×10-3~0.8μg/mL(r=0.999 4)的浓度范围内与峰面积成良好的线性关系,检测限(S/N=3)为1.4×10-4μg/mL.实验表明该法简便、快速,应用于实际肉牛组织中磺胺二甲基嘧啶的测定,取得了很好的结果.  相似文献   

10.
建立了N'-(4,6-二甲氧嘧啶-2-基)-N-β-吡啶甲酰基硫脲的高效液相色谱分析方法.采用ODS色谱柱,以乙腈∶水=90∶10(v∶v)为流动相,流速1 mL/min进行分离,以紫外检测器在波长224 nm下进行测定.该方法回收率在98.76%~100.18%之间,线性相关系数为0.9996,标准偏差为0.119,变异系数为0.123%.  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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