通过式固相萃取结合超高效液相色谱-四级杆飞行时间质谱筛查鱼肉中多类兽药残留

采用通过式固相萃取技术作为样品净化方法,液相色谱-四级杆/飞行时间质谱(HPLC-Q-TOF/MS)作为检测手段,建立了水产品中磺胺类、β-内酰胺类、头孢类、苯并咪唑类衍生物、氟喹诺酮类等37种兽药的高通量快速筛查技术。样品经80%乙腈水溶液提取,Oasis PRi ME HLB固相萃取小柱通过式净化,分析物经Waters ACQUITY UPLC BEH C18反相柱分离,以0.1%甲酸水溶液-乙腈作为流动相梯度洗脱,电喷雾正离子模式检测,以保留时间、化合物精确分子离子质量和特征碎片离子质量对药物进行定性定量分析。37种兽药在各自的线性范围内线性关系良好,相关系数大于0.98,定量限为5.0~50μg/kg,3个加标水平下的平均回收率为66.2%-86.5%,相对标准偏差(RSD,n=5)均小于15.0%。本方法前处理简单,检测快速高效准确,适用于实际水产品中多种兽药的筛查和确证。将建立的方法应用于农业部水产品风险监测、浙江省风险监测和舟山市投入品筛查等的兽药残留的筛查工作中,筛查出一例利福平残留和一例红霉素残留。     

快速分离柱-高效液相色谱法测定头发中的尼古丁和可天宁

 研究了用快速分离柱-高效液相色谱测定头发中尼古丁和可天宁的方法.样品中的尼古丁和可天宁用ZORBAX Stable Bound(Φ4.6 mm×50 mm,1.8μm)C18快速分离柱为固定相,15%的乙腈(内含0.02 mol/L十二烷基磺酸钠和0.05 mol/L pH值为3.0的磷酸盐缓冲)为流动相,紫外检测波长为260 nm,流速为2.0mL/min.在该色谱条件下,尼古丁和可天宁在1.0 min内即可达到基线分离.方法标准回收率94%~104%,相对标准偏差分别为2.3%和2.4%.新方法应用于主动吸烟和被动吸烟者头发中尼古丁和可天宁的测定,结果令人满意.     

SPE-HPLC法测定环境水样中3种痕量抗生素的含量

建立了一种固相萃取-高效液相色谱法同时测定水体中氧氟沙星、四环素、磺胺甲噁唑浓度。样品经固相萃取小柱富集净化、超纯水-乙腈(75∶25,体积比)洗脱后,用高效液相色谱-紫外检测器测定。检测波长λ为274 nm,柱温30℃,流动相为乙腈-磷酸水溶液(50∶50,体积比),采用梯度洗脱程序,实现了3种待测组分的基线分离,线性范围为氧氟沙星0.25~2μg/mL,四环素0.4~2μg/mL,磺胺甲噁唑0.04~2μg/mL。空白加标回收率范围分别为82.32%~94.86%。氧氟沙星、四环素、磺胺甲噁唑的检出限分别为0.04、0.25、0.01μg/mL,定量限分别为0.25、0.40、0.04μg/mL。该方法具有快速简便、灵敏高效等优点,可满足实际工作的需要。     

固相萃取-高效液相色谱法测定枸杞子中吡虫啉残留量

建立固相萃取-高效液相色谱法测定枸杞子中吡虫啉残留量.样品用乙腈提取,中性氧化铝和活性炭固相萃取柱净化,分析时采用Inertsil(R) ODS-3(25cm×4.6 mm,5μm)色谱柱分离,以乙腈-水为流动相梯度洗脱,流速1.0 mL/min,检测波长为270 nm,柱温35 ℃.试验结果表明,在0.02～5.0 mg/L范围内,吡虫啉峰面积与浓度呈良好的线性关系(r=0.9999),枸杞子样品中吡虫啉能得到良好的分离,回收率及重复性良好.     

黄连中小檗碱的定性与定量分析

通过高效液相色谱法对传统中药黄连中的主要成分小檗碱的含量进行测定.使用kromasil C18色谱柱(250 mm×4.6 mm,5μm)以乙腈和水作为流动相进行梯度洗脱流速1 mL/min,检测波长为345 nm.盐酸小檗碱浓度在5μg/mL～50μg/mL范围内线性关系良好,平均加样回收率为99.56%,RSD为2.75%.本方法简便、准确、快速、重复性好,可用于黄连中小檗碱的含量测定.     

高效液相色谱法测定鞣酸小檗碱的含量

建立HPLC测定鞣酸小檗碱含量的方法,以提高其质量标准。Waters C18(250mm×4.6mm,5μm)色谱柱;以乙腈-0.1%磷酸(每100mL含0.1g十二烷基磺酸钠和0.1mL三乙胺)溶液为流动相;检测波长为345nm;流速1.0mL/min;柱温35℃。鞣酸小檗碱在0.05~0.40μg范围内呈良好的线性关系(R2=0.9992);鞣酸小檗碱平均加样回收率为98.56%,RSD%为2.6%。该方法简单、快速、准确,可用于鞣酸小檗碱的含量测定。     

亲水作用色谱法测定左卡尼汀注射液含量及杂质A

通过考察流动相中有机相的比例、缓冲液浓度、pH值、柱温以及流速等因素的影响,建立亲水作用色谱法测定左卡尼汀注射液含量及杂质A的方法.最终确定的色谱条件为采用XBridgeAmide色谱柱(4.6mm×250mm,3.5μm),以缓冲液(10mmol/L乙酸铵,用冰醋酸调节pH值5.0)-乙腈(20∶80)为流动相,柱温40℃,检测波长205nm.经方法学验证,左卡尼汀与杂质A分离度良好(R>1.5),左卡尼汀与杂质A浓度分别在0.530~3.21mg/mL、2.06~82.4μg/mL范围内线性关系良好,平均回收率(n=9)分别为100.4%和101.2%.杂质A检测限(S/N=3)为29.0ng/mL、定量限(S/N=10)为68.7ng/mL.结果表明该法可用于左卡尼汀注射液质量的控制.     

固相萃取与高效液相色谱联用快速测定鲜奶中的三聚氰胺

采用固相萃取-高效液相色谱法测定鲜奶样品中的三聚氰胺.固相萃取柱为Strata-X-C,液相色谱柱Thermo BDS HYPERSIL C8(4.6 mm×250 mm,5μm);流动相为乙腈:0.01 mol/L辛烷磺酸钠-柠檬酸缓冲溶液(10:90,V:V),检测波长为 238 nm.三聚氰胺峰的保留时间为 8.25 min.三聚氰胺在 1.0～50μg/mL 范围内具有良好的线性关系(R=0.997),在添加量为30,60,90 mg/kg 时,三聚氰胺标准加入回收率为90.40%～91.10%,RSD为1.14%～1.88%.方法检出限为0.1 mg/kg.     

高效液相色谱法测定帕布昔利布含量

为建立帕布昔利布(PD)含量测定方法,采用高效液相色谱法,色谱柱为Agilent HC C_(18)(250mm×4.6mm,5μm),流动相为乙腈-水(二者体积比为300∶700,含0.1%(体积分数)三氟乙酸),流速为1.0 mL/min,按照等度洗脱,进样量为10μL,检测波长为234nm,柱温为40℃。结果表明:主药与各杂质之间分离度良好;帕布昔利布质量浓度在50~150μg/mL范围内与峰面积线性关系良好,r为0.999 5;仪器精密度、中间精密度、稳定性试验的RSD值小于2.0%;帕布昔利布回收率为100.0%,RSD值为0.8%(n=9)。本方法可以准确快速测定PD含量,有效排除其他外界因素的影响,为帕布昔利布原料药含量测定提供新的参考。     

用快速分离柱高效液相色谱法测定中草药中的重金属元素

研究了用固相萃取富集,快速分离柱高效液相色谱法测定中草药中4种重金属元素:镍、铅、镉、汞的方法.中草药样品用微波消化,样品消化液中的镍、铅、镉、汞用四-(间氨基苯基)-卟啉(T2APP)柱前衍生,然后用ZORBAX RP18固相萃取小柱萃取富集镍、铅、镉、汞的T2-APP络合物,富集倍数为50倍;经富集后的络合物用乙腈和0.05 mol.L-1pH=10.0四氢吡咯-醋酸缓冲液(92/8)为流动相,ZORBAX Stab le Bound(4.6mm×50 mm,1.8μm)快速分离柱为固定相分离,用二极管矩阵检测器检测.镍、铅、镉、汞的检测限分别为:4,4,3,2 ng.L-1,分离4种重金属元素络合物的时间只需2.0 m in.方法相对标准偏差为1.8%~3.4%,标准回收率为88%~103%.     

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     

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     

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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