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1.
建立了花色蛤中扑草净含量的毛细管气相色谱测定方法.采用SPL进样口,毛细管色谱柱rtx-5(弱极性,30m×0.25 mm×0.25μm),火焰光度检测器(FPD)进行检测.进样口温度,250℃,分流比5∶1,载气流速,1.47 m L/min;线速率控制方式:线速率,37 cm/s,柱室温度,100℃保持1 min,以30℃/min升至220℃,保持10 min;检测器温度,250℃,氢气气流量,40 m L/min,空气流量,60 m L/min.实验结果表明:方法简单、快速、重现性好,平均回收率大于85%,RSD小于6.0%,线性范围为0.05~1μg/m L,检出限(定性限)为0.001 mg/kg.  相似文献   

2.
目的建立新型毒品苄基哌嗪的气相色谱-质谱联用(GC-MS)检测方法。方法通过考查进样口温度、柱温箱初始温度、柱温箱保持温度、分流比、柱流速、全扫描质谱范围及升温速率7个参数对分离度、信噪比、峰面积、峰高及保留时间的影响,建立苄基哌嗪的气相色谱-质谱联用分析方法,并对所建分析方法的线性范围进行考查。结果在进样口温度为280℃、柱温箱初始温度为140℃、柱温箱保持温度205℃、分流比20∶1、柱流速为1.2 m L/min、全扫描质谱范围是41~200 amu、柱温箱升温速率为17℃/min条件下,苄基哌嗪浓度为0.01 mg/m L到1.0 mg/m L之间时,样品浓度与峰面积呈线性关系,检出限为0.324 3μg/m L,保留时间为3.515 min。结论该方法测定苄基哌嗪快速、灵敏、准确、可靠。  相似文献   

3.
采用气相色谱法及残留溶剂测定法对莫西沙星侧链的残留溶剂进行测定.色谱柱采用6%氰丙基苯基—94%二甲基聚硅氧烷为固定液的毛细管柱(DB-624,30m×0.32mm×1.8μm),柱温80℃,维持5min后,以8℃/min的速率升温至200℃,维持15min;检测器为氢火焰离子化检测器,检测温度为270℃,进样口温度为250℃,载气流速3.0mL/min,分流比10∶1.实验结果显示,本方法可以有效、准确地检测出莫西沙星侧链的残留溶剂.  相似文献   

4.
建立气相色谱测定小儿奇应丸中冰片含量的方法.毛细管气相色谱柱为DB-WAX毛细管柱(30 m×0.32 mm×0.25μm),色谱柱温度为140℃,进样口温度为200℃,检测器温度为200℃,载气为氮气,分流比为50∶1,流量为1.0 m L·min~(-1).在该实验条件下,样品中的冰片能很好的分离,冰片在0.02~1.8μg范围内成良好的线性关系(r2=0.998 5,n=11),加样回收率为99.78%(RSD=0.93%,n=6).该方法操作简便,灵敏度高,准确度好,可为小儿奇应丸的质量标准提供理论依据.  相似文献   

5.
建立了液液萃取—高效液相色谱法测定水样中α-萘酚和β-萘酚的分析方法。对流动相组成及流速、柱温、萃取剂种类、色谱柱类型等条件进行了优化。选用三氯甲烷为萃取剂,乙腈:水(0.1%乙酸)=50:50为流动相,流速1m L/min,柱温40℃,作为色谱条件。在1L空白水样中添加低浓度水平的萘酚标准溶液(加标量为0.2μg),测定平行样品7份,α-萘酚加标回收率为92%~117%,标准偏差为5.5%;β-萘酚加标回收率为96%~121%,标准偏差为5.1%。当萃取体积为1L,浓缩至1m L,进样量为10μL时,α-萘酚和β-萘酚的方法检出限分别为0.15μg/L和0.17μg/L。  相似文献   

6.
采用沸水浴处理、正己烷液液萃取方式处理样品后,通过对色谱柱、进样温度、载气流速、程序升温、检测器温度、进样量等进行选择与优化,建立了白酒中3种常规白酒塑化剂的气质联用(GC-MS)检测方法:采用Agilent 19091S-433色谱柱(30m×0.25 mm×0.25μm);进样口温度250℃;升温程序:初始柱温60℃,保持1min,以20℃/min升温至220℃,保持1min,再以5℃/min升温至280℃,保持4min;载气:氦气(纯度99.999%),流速1ml/min;进样方式:不分流进样;进样量:1μL.质谱条件:色谱与质谱接口温度250℃;电离方式:电子轰击源(EI);监测方式:选择离子扫描模式(SIM).电离能量:70e V;溶剂延迟:7min.用该法对湘窖酒业有限公司的4个不同环节的白酒样品中3种邻苯二甲酸酯残留(DBP、DEHP、DINP)进行检测,结果表明所建方法加标回收率为91.4%~105.7%,精密度为2.5%~9.3%,在0.1~10.0mg/L范围内,线性关系良好,相关系数为0.977~0.998,检出限为0.05mg/L.方法简单、灵敏、快速、抗干扰能力强,定性、定量准确并且具有良好的重现性和精密度,适合于白酒中3种常规邻苯二甲酸酯污染物检测.加强白酒储藏与运输环节关键点的控制,确保白酒质量与安全.  相似文献   

7.
毛细管气相色谱法测定白芍中有机氯农药的含量   总被引:4,自引:1,他引:3  
在建立白芍中七氯、环氧七氯及滴滴涕异构体含量的气相色谱分析方法中,样品以石油醚加丙酮在索氏提取器中提取,提取液以浓硫酸净化;采用DB-5(30 m×0.25 mm×0.25μm)弹性石英毛细管柱分离样品;以GC-ECD检测农药七氯、环氧七氯及滴滴涕的含量(色谱条件:载气为N2(99.999%,1.5 mL/min);分流比为2.3∶1;进样器温度为200℃,检测器测试为330℃,柱升温程序是从100℃(保持0.5 min)开始以15℃/min升至200℃保持1.0 min),再以4℃/min升至240℃(保持7 min);方法的加标平均回收率为96.27%~100.3%,精密度为2.0%~6.9%。  相似文献   

8.
建立毛细管气相色谱法,分别采用溶液直接进样与顶空进样法测定睾酮衍生物AD中溴代环戊烷的残留量。溶液直接进样法:色谱柱为DB-WAX石英毛细管柱,采用程序升温,初始温度50℃,保持5 min;然后以30(℃·min-1)升温至200℃,保持7 min。顶空进样法:顶空瓶加热温度90℃,平衡时间30 min。测得溴代环戊烷分别在4.17~83.4(μg·m L-1)和0.139~2.78(μg·m L-1)范围内呈良好线性关系。回收率分别为100.65%、99.82%。这两种方法均可检测睾酮衍生物AD中溴代环戊烷的残留量,而顶空进样法灵敏度更高,对色谱柱污染较小。  相似文献   

9.
目的:采用气相色谱建立复方水合氯醛口服溶液中水合氯醛的含量测定方法。方法:色谱柱:OV-624毛细管柱(30m×0. 53 mm,0. 5μm);柱温:100℃;氢离子火焰检测器(FID)温度:250℃;进样口温度:200℃;载气压力:氮气50 k Pa;氢气50 k Pa;空气流量:40 m L/min;进样量:1μL,进样方式:分流进样(1∶100);在此条件下进行方法学考察。结果:测定复方水合氯醛口服溶液中水合氯醛含量时,各方法学参数满足《中国药典》要求,水合氯醛在125μg/m L~2000μg/m L呈良好线性关系,精密度、重复性RSD分别为1. 96%、2. 97%;样品平均回收率为101. 04%,RSD为2. 03%。结论:气相色谱法适用于复方水合氯醛口服溶液中水合氯醛含量测定,且操作方便,简单易行。  相似文献   

10.
采用反相高效液相色谱法检测人体血浆中替勃龙的含量.以5倍样品体积的乙腈萃取2次,经氮气吹干,甲醇溶解后,上机分析.采用Promosil-C18色谱柱(4.6mm×250mm,5μm),流动相:甲醇-乙腈-水,流速:1.0mL/min,进样量:10μL,检测波长:204nm,柱温:25℃.在优化的色谱条件下,替勃龙在0.5~250.0μg/mL内线性关系良好(r=0.999 9),最低检测限为0.05μg/mL,平均回收率(n=3)为92.7%,RSDs小于1.6%.本方法简单,灵敏,准确,适合于体内替勃龙含量的检测与分析.  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.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<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   

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