液相色谱-串联质谱法同时快速测定婴幼儿谷物食品中3种莨菪烷生物碱

采用固相萃取净化去除样品中蛋白类物质的干扰,建立婴幼儿谷物食品中3种莨菪烷生物碱的液相色谱-串联质谱检测方法.样品经体积分数为80％(v/v)乙腈水溶液提取后,经Oasis PRiME HLB SPE固相萃取柱净化.净化后的样品采用Agilent Poroshell 120 EC-C18柱(2.7μm,3.0 mm×75 mm)分离,以0.1％(v/v)甲酸乙腈溶液和0.1％(v/v)甲酸水溶液为流动相,梯度洗脱,多反应监测正离子模式扫描,采用基质溶液外标法定量.3种莨菪烷生物碱在1.0～50.0μg·L-1浓度范围内线性关系良好(R2﹥0.999),方法的检出限均为0.5μg·kg-1;回收率为86.8％ ～103.3％,相对标准偏差为5.2％ ～8.9％.该方法前处理操作简便,灵敏度和准确度高,可实现婴幼儿谷物食品中3种莨菪烷生物碱的同时快速测定.     

LC-MS法测定新型VMAT2抑制剂LPM3770164中的樟脑磺酸酯

本文建立了LC-MS法对LPM3770164中的樟脑磺酸甲酯(MCS)、樟脑磺酸乙酯(ECS)进行定量检测。采用色谱柱ACQUITY UPLC Peptide CSH C18(150 mm×2.1 mm, 1.7μm),以10 mmol·L^-1乙酸铵溶液-乙腈(90∶10,V/V)为流动相A、乙腈为流动相B进行梯度洗脱。质谱采用电喷雾正离子化选择离子监测模式进行检测。经方法学验证结果表明,MCS在1.97～14.79 ng·mL^-1内线性关系良好(r=0.999 9);ECS在1.90～14.26 ng·mL^-1内线性关系良好(r=0.999 9)。通过加样回收率试验,MCS、ECS的平均回收率(n=9)分别为98.5%、99.1%。研究表明该方法操作简便,灵敏度高,可用于LPM3770164中樟脑磺酸甲酯、樟脑磺酸乙酯的测定,并为其质量控制提供参考。     

高效液相色谱-串联质谱法对贯叶连翘中4种黄酮醇类化合物抗氧化活性的定量研究*

建立了高效液相色谱-串联质谱(HPLC-ESI/MS)法对芦丁、金丝桃苷、槲皮素和槲皮苷的抗氧化活性进行定量研究。样品用甲醇溶解,采用Hewlett Packard ODS Hypersil C_(18)色谱柱(100 mm×4.6 mm,5μm)、0.1%甲酸水-甲醇为流动相梯度洗脱,流速0.6 m L·min~(-1),柱温25℃;电喷雾源,负离子模式多反应选择离子检测(MRM),用于定性、定量的母离子和子离子分别为m/z 609→300(芦丁)、m/z 463→300(金丝桃苷)、m/z 301→151(槲皮素)、m/z 447→300(槲皮苷),采用外标法进行定量分析。结果表明:芦丁、金丝桃苷、槲皮素和槲皮苷在0.5~1 600 ng·mL~(-1)范围内线性关系良好(R0.998),定量限为0.5 ng·m L~(-1),仪器精密度良好(RSD3.0%),样品反应液在24 h内稳定性良好。本方法具有灵敏度高,分析时间短等特点,相对于其他检测方法,提高了检测的准确性,适用于对贯叶连翘中黄酮醇类化合物抗氧化活性的定量研究。经计算,芦丁、金丝桃苷、槲皮素和槲皮苷对ABTS~(.+)的清除率分别为18.35%、36.28%、41.50%和37.18%。     

液相色谱—串联质谱法测定中华绒螯蟹中21种磺胺类药物残留

建立了一种液相色谱-电喷雾串联质谱同时测定中华绒螯蟹中21种磺胺类药物残留的方法.均质样品先后用乙腈、二氯甲烷提取,合并提取液,取部分提取液经氮吹浓缩.残渣用1 mL流动相溶解,饱和正己烷脱脂净化.采用ZOR-BAX Eclipse XDB-C8色谱柱,以含0.2%乙酸的水溶液和甲醇(7:3)为流动相,梯度洗脱,在电喷雾-多反应监测离子模式下,进行定量定性分析.方法的定量限为5μg/kg;以标准加入法计算回收率,在4～40μg/kg添加范围内,平均回收率为71.8%～106%;相对标准偏差为0.44%～10.1%.     

液相色谱—串联质谱法检测蜂王浆中三环锡残留量

本实验研究建立了蜂王浆中三唑锡残留量的液相色谱-质谱串联检测方法.三环环锡经过酸化乙腈提取,经固相萃取柱,C-18色谱柱梯度洗脱分离,取365.1→201.1,365.1→283.2,365.1→219.1 m/z为主要特征离子365.1→201.1 m/z为定量离子,以三重四级杆为质量检测器检测三环锡的方法.该方法线性范围:1-50 ng/g,仪器检出限:1 ng/g;添加浓度20 ng/g、25 ng/g、50 ng/g回收率:80％～105％,相对标准偏差3.9％～8.8％.     

亲水作用毛细管电色谱分析苷类药物的研究

基于多面体寡聚硅倍半氧烷-甲基丙烯酸羟乙酯poly(POSS-MA-co-HEMA)有机硅胶杂化整体柱,建立典型苷类药物(连翘苷、豆腐果苷、紫丁香苷、天麻素)的亲水作用毛细管电色谱检测技术.考察流动相乙腈比例、缓冲液浓度、缓冲溶液p H值、分离电压和反压阀压力对四种苷类药物分离效果的影响,在最优条件下(流动相为2 mmol·L-1磷酸三乙胺缓冲液(乙腈体积分数为90%,p H=7.0),分离电压-8 k V、柱压力5.4MPa),4种苷类药物在10 min内得到了基线分离.连翘苷、豆腐果苷、紫丁香苷和天麻素线性范围分别为10~200、25~200、15~200和25~200μg·m L-1,检测限为1.5~8.0μg·m L-1.应用于血清模拟样品分析,平均回收率为95.6%~99.1%,相对标准偏差小于3.3%.     

HPLC/MS/MS法同时测定小鼠血浆中人参皂苷Rg1、Re、Rb1

利用高效液相色谱-串联质谱联用的技术,建立同时测定小鼠血浆中的人参皂苷Rg1、Re、Rb1浓度的分析方法.以RESTEK PinnacleⅡC18柱(50 mm×2.1 mm,5 μm)为色谱柱,流动相:乙腈-水(梯度洗脱);流速200 μL·min-1;柱温:20 ℃;质谱条件为气动辅助电喷雾离子源(ESI),检测方式为正离子多离子反应监测(MRM),用于定量分析的离子为m/z Rg1 832.8→643.6;Re 969.8→789.7;Rb11132.1→365.3;生物样品采用固相萃取方法处理.人参皂苷Rg1、Re、Rb1标准曲线的线性范围为0.5～1 000 ng·mL-1,最低定量下限达到0.5 ng·mL-1,日内、日间变异系数(RSD)均<15%,精密度和准确度等均符合生物样品分析的要求.结果表明该法准确、灵敏、特异,适用于血浆中人参皂苷Rg1、Re、Rb1浓度的同时测定.     

超高效液相色谱-串联质谱法测定保健品中15种那非类药物

本研究建立了超高效液相色谱-串联质谱法检测保健品中15种那非类药物的分析方法。样品经乙腈直接提取,用Waters Acquity BEH C_(18)柱(2.1mm×100mm,2.5μm)分离,以0.1%甲酸水和乙腈为流动相梯度洗脱,电喷雾正电离多反应模式监测,外标法定量。结果表明:15种那非类药物在0.1～50 ng/mL浓度范围内线性关系良好,相关系数大于0.999 0;检出限为2.5～12.5μg/kg;定量限为5.0～25.0μg/kg;加标水平为5.0μg/kg～250μg/kg时,回收率范围为72.4%～97.6%;相对标准偏差为0.77%～9.91%;此方法简便快速、选择性强、灵敏度高,可用于保健品中15种那非类药物的测定。     

HPLC法同时测定外感风痧颗粒中4种成分

本文建立同时测定外感风痧颗粒中原儿茶酸、原儿茶醛、绿原酸、咖啡酸4种成分的HPLC方法。色谱柱为依利特Hypersil C18柱(250 mm×4.6 mm,5μm);流动相为乙腈-0.2%磷酸,梯度洗脱,流速1.0mL·min~(-1);柱温25℃。结果显示:4种指标成分分离效果良好,原儿茶酸在3.672～33.048μg·mL~(-1)、原儿茶醛在1.236～11.124μg·mL~(-1)、绿原酸在9.2～82.8μg·mL~(-1)、咖啡酸在1.488～13.392μg·mL~(-1)线性关系良好;平均加样回收率均为97.6%～103.3%。本方法准确、灵敏、可靠,重现性较好,可用于外感风痧颗粒的质量控制。     

固相萃取-气相色谱-质谱联机分析蜂蜜中的氯霉素残留量

利用固相萃取气相色谱质谱联机分析蜂蜜中的氯霉素残留量.对氯霉素在固相萃取柱上的保留行为进行了研究,优化固相萃取条件,发现不同浓度的氯霉素在硅胶柱和C18柱上的回收率均在90%以上,蜂蜜加标的回收率为80%～95%,相对标准偏差为7.2%～18.2%,最低检出限为0.1μg·kg-1.对氯霉素的三甲基硅烷化衍生物采用选择离子的模式进行检测(m/Z=466,468,470),衍生物的峰面积与样品质量浓度在0.55～220μg*L-1范围内呈良好的线性关系,线性回归系数为0.9998.Ζ=466,468,470)衍生物的峰面积与样品质量浓度在0.55～220μhg·L-1范围内呈良好的线性关系,线性回归系数为0.9998.     

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