自动索氏提取-高效液相色谱法同时测定油炸面制品中的16种多环芳烃

采用自动索氏提取法以丙酮:正己烷(1 : 1)混合溶液提取油炸面制品中的乡环芳烃(PAHs),以硅胶固相萃取柱净化,二氯甲烷:正己烷(5:6)洗脱,建立了同时测定油炸面制品中16种PAHs的高效液相色谱-紫外和荧光检测器测定方法.实验结果,在50μg/kg添加水平,PAHs各化合物的回收率为92.5%～106.4%,相对标准偏差(RSD)小于3.21%.16种PAHs化合物检出限为0.8μg/kg～40μg/kg.该方法简便、快速、可同时检测油炸面制品中16种PAHs.     

固相微萃取联用气相色谱测定水中的多环芳烃

采用溶胶-凝胶法制备的离子液体键合固相微萃取涂层联用气相色谱测定水中的萘、联苯、芴、菲、荧蒽5种多环芳烃(PAHs).对固相微萃取的条件进行优化.方法的检测限为0.0005～0.05μg/L,线性范围在0.1～100 μg/L,相对标准偏差(RSD)不大于5.3％.对东湖水样进行测定,未检测到5种多环芳烃,其回收率为71.0％～107.9％.     

改性TiO_2纳米管介质用于快速检测柴油机排放多环芳烃的研究

使用阳离子表面活性剂CTAB对二氧化钛纳米管阵列进行修饰作为固相微萃取(SPME)材料,对固相微萃取的参数如提取时间、解吸时间和解吸溶剂进行优化,用于检测船舶柴油机排放的非常规污染物多环芳烃.优化的SPME条件为:CTAB浓度为90 mg/L;有机溶剂为二氯甲烷;pH值为7;解吸液为二氯甲烷;解吸附时间为6 min.16种多环芳烃在浓度范围0.5~100μg/L之间呈良好的线性关系,相关系数均达到0.990以上,检测限达到0.001~0.005μg/L,样品加标回收率范围为80.1%~99.2%,日内精密度(n=6)的相对标准偏差范围在3.7%~9.1%之间.新方法的样品采集和预处理时间比传统方法节约90%,方法灵敏、准确,可以用于快速检测柴油机非常规排放.     

固相萃取-高效液相色谱检测吸烟人群尿中8种单羟基多环芳烃

采用固相萃取(solid phase extraction,SPE)前处理结合高效液相色谱荧光检测(high performance liquid chromato graphy fluorescence detection,HPLC-FD),建立了检测吸烟人群尿中8种羟基多环芳烃(OHpolycyclic aromatic hydrocarbons,OH-PAHs,环数2～5)的SPE-HPLC-FD分析方法;在优化后的SPE和HPLC-FD条件下,内标法定量检测尿中8种OH-PAHs.结果表明,标准曲线方程的线性范围为0.2～20μg/L或0.5～20μg/L,决定系数R20.998,方法定量限(method quantification limit,MQL)为0.03～0.07μg/L,回收率R为(70%±4%)～(109%±30%),日间重现性为5%～28%.当地吸烟者尿样分析结果显示,本方法能够检测其尿中不同环数的OH-PAHs,可用于当地吸烟人群PAHs暴露健康风险评价.     

分散固相萃取-超低温液液微萃取-气相色谱质谱法测定烟熏及烧烤肉制品中16种欧盟优控多环芳烃

建立了分散固相萃取-超低温液液微萃取-气相色谱质谱法测定烟熏及烧烤肉制品中16种欧盟优控多环芳烃的分析方法。样品用乙腈提取、上清液经分散固相萃取净化后在-80℃条件下采用甲苯液液微萃取浓缩,选用DB-EUPAH色谱柱(20m×0.18mm×0.14μm)分离,最后经质谱检测定量。结果表明,16种欧盟多环芳烃在5~500μg/L浓度范围内线性关系良好,相关系数均大于0.999,对烟熏和烧烤的肉制品进行3个不同浓度的加标实验,平均回收率为75.2%~114.2%,RSD为1.84%~7.57% (n=6),检出限(S/N=3)为0.1~0.5μg/kg。 应用该方法对40批次市售腊肉制品和烤肉制品中多环芳烃进行了检测,发现部分腊肉制品和烤肉制品中多环芳烃含量超过相关标准和法规的限量要求。 该检测方法成本低,灵敏可靠,同时符合国家标准和欧盟法规对烟熏及烧烤肉制品中多环芳烃的限量检测要求。     

凝胶净化-固相萃取-高效液相色谱法同时测定烤肉中的16种多环芳烃

建立了烤肉中16种多环芳烃的凝胶净化-固相萃取-高效液相色谱(GPC-SPE-HPLC)的定量检测方法.样品经丙酮:正己垸(1:1)混合溶液超声30min提取.凝胶色谱和硅胶固相萃取净化,高效液相色谱配荧光检测器和紫外检测器分析.结果表明:线性关系R≥0.997.在50μg/kg添加水平各化合物的回收率为88.4%~102.1%,RSD(n=7)≤5.35 oA.检出限为0.2pg/kg~1.0μg/kg.该方法灵敏度高、重现性好,可同时检测烤内中16种PAHs.     

自制固相微萃取涂层同时测定水中的多环芳烃和酞酸酯

采用自制的固相微萃取涂层, 通过顶空固相微萃取与气相色谱法（HS SPME GC）联用测定水中的多环芳烃(PAHs)和酞酸酯(PAEs), 并优化了固相微
萃取条件. 实验结果表明： 当样品中加入4 g NaCl, 并以一定速度搅拌, 70 ℃顶空萃取50 min, 280 ℃解吸5 min时, 其检测限为0.005～0.1 μg/L, 线性范围为1～100 μg/L. 使用该方法检测武汉市东湖水样的加标回收率为72.0%～116.3%, 相对标准偏差(RSD)为5.2%～8.5%.     

同步荧光法测定河水中的多环芳烃

该文建立了河水中多环芳烃混合物同时测定的同步荧光分析法。该法简便快速,无需对混合物进行分离,就可实现7种组分的同时鉴别和定量测定。7种多环芳烃（PAHs）在0～1000ng/mL范围内呈良好的线性关系,相关系数r均不小于0.9965,相对标准偏差（RSD）在0.24%～1.48%之间（n=6）。该方法的检出限在0.28～3.45ng/mL。此方法应用于分析河水样中的多环芳烃取得了良好的效果,回收率分别为66.3%～103.9%、79.3%～106.8%、73.9%～100.3%、73.8%～94.6%。     

LC/MS对烘焙食品中乙酰磺胺酸钾(安赛蜜)含量的检测

以超高效液相色谱质谱联用仪(LC/MS)法检测烘焙食品中乙酰磺胺酸钾(安赛蜜)的含量。采用Eclipse Plus C18柱(3.0×100mm,1.8μm)分离;以乙腈-0.47 g/L乙酸铵水溶液(含0.2%(v/v)甲酸)为流动相进行梯度洗脱,流速为0.3mL/min,柱温35℃;以多反应离子监测(MRM)为检测方式,采用负离子扫描,喷雾器压力45 psi,碰撞氮气气流量8L/min;离子源温度350℃;毛细管电压4000V;光电倍增管电压600 V。安赛蜜在10.0μg/L¹00.0μg/L范围内线性良好(r2>0.999),方法的定量限(LOQ)为10.0μg/L,检测信噪比大于10,满足实际检测需要。加标回收率在92.3%100.0μg/L范围内线性良好(r2>0.999),方法的定量限(LOQ)为10.0μg/L,检测信噪比大于10,满足实际检测需要。加标回收率在92.3%⁹9.8%之间,相对标准偏差(RSD,n=6)为4.5%99.8%之间,相对标准偏差(RSD,n=6)为4.5%⁶.0%,检测结果令人满意。     

微波萃取-气相色谱质谱法测定土壤中的多环芳烃

本文通过微波萃取的方法提取土壤中的15种多环芳烃(PAHs),萃取液经硅酸镁(Florisil)固相萃取柱净化,采用DB-5MSUI毛细管柱(30 m×0.25 mm×0.25μm)进行分离,使用气相色谱-质谱进行测定分析.方法的加标回收率为70.85%～117.90%,相对标准偏差(RSD)为2.1%～6.7%.微波萃取比其他萃取方法回收率高,重复性好,方法简单快速,具有良好的精密度,可以满足土壤中多环芳烃的提取,建立的方法可以满足土壤中多环芳烃测定的技术要求.     

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.     

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     

Call for Papers

<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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has