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。     

聚合物-盐-水析相体系液-固萃取动力学光度法测定痕量钴

将析相萃取技术与催化动力学光度法相结合,建立了一个测定痕量钴的聚合物-盐-水体系析相萃取-催化动力学光度法。在Na₂HPO₄-NaOH缓冲溶液中,Co²⁺可灵敏催化过氧化氢氧化苯芴酮褪色反应,用聚乙烯吡咯烷酮-硫酸铵-水的非有机溶剂萃取体系萃取出未被氧化的指示物苯芴酮与水相中的氧化剂分离,从而可终止该反应并通过测量有机相的吸光度显著提高分析的灵敏度。钴浓度在0 μg/L~0.03μg/L范围内与ΔA呈线性关系,检测限为3.4×10^-5 μg/L。该方法灵敏度高,选择性好,用于直接测定水样中超痕量钴,结果满意。     

高效液相色谱法测定水中α-萘酚和β-萘酚

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。     

有序介孔炭固相萃取-毛细管电泳联用测定水样中抗生素残留

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.     

非有机溶剂液-液萃取分光光度法测定微量钯

研究了聚乙二醇-2000(PEG-2000)水溶液在硫酸铵存在下分为液-液两相的条件和对硝基偶氮氯膦(CPA-pN)与钯(μ)反应生成的配合物在该萃取体系两相间的分配行为．实现了钯(II)的定量萃取分离．在此基础上建立了非有机溶剂液-液萃取分光光度法测定微量钯(Ⅱ)的新方法．该方法的检出限为0．03／μg／mL，线性范围为0．09～1．5μg／mL，用于铂钯二次精矿和人工合成样品中微量钯的测定，结果令人满意．     

聚合物-盐-水析相体系液-因萃取动力学光度法测定痕量钴

将析相萃取技术与催化动力学光度法相结合,建立了一个测定痕量钴的聚合物-盐-水体系析相萃取-催化动力学光度法.在Na2HPO4-NaOH缓冲溶液中,Co2+可灵敏催化过氧化氢氧化苯芴酮褪色反应,用聚乙烯吡咯烷酮-硫酸铵-水的非有机溶剂萃取体系萃取出未被氧化的指示物苯芴酮与水相中的氧化剂分离,从而可终止该反应并通过测量有机相的吸光度显著提高分析的灵敏度.钴浓度在0μg/L～0.μg/L范围内与△A呈线性关系,检测限为3.4×10-5μg/L.该方法灵敏度高,选择性好,用于直接测定水样中超痕量钴,结果满意.     

气相色谱-串联质谱检测烟草中10种酰胺类除草剂残留

采用固相萃取-气相色谱-串联质谱来测定烟草中10种酰胺类除草剂的残留量。烟草样品通过含1%乙酸的乙腈混合液提取,固相萃取净化,采用气相色谱分离,串联质谱多反应监测模式分析。10种酰胺类除草剂在0.01~1.0 mg/L线性范围内均呈良好线性关系,相关系数大于0.997,方法的检出限在0.2~4.7μg/kg之间。在10μg/kg,50μg/kg,100μg/kg等3个浓度水平下进行加标实验,其加标回收率在79.6%~101.4%之间,测定值的相对标准偏差(n=6)在1.6%~6.7%之间。建立的方法简便、快速、灵敏,为常见烟草中酰胺类除草剂残留的准确判断提供了可靠依据,适用于烟草中10种酰胺类除草剂的同时检测。     

磁性石墨烯-液质联用测定鸡肉中万古霉素和喹诺酮

建立了鸡肉中万古霉素和喹诺酮类药物残留的磁性石墨烯固相萃取-液相色谱-串联质谱分析方法.样品采用乙腈提取,磁性石墨烯粉分散固相萃取净化,经Agilent ZORBAX SB-C18(3.0 mm ×100.0 mm,1.8 μm)色谱柱分离,液相色谱-串联质谱仪进行检测.目标物在2.0~50.0 μg/L内线性关系良好(r²>0.99).鸡肉基质中目标化合物在5、10、25 μg/kg加标水平的回收率为71.2%~98.8%,相对标准偏差(RSD)为6.8%~14.3%.该方法净化效果好,回收率高,精密度好,可用于鸡肉中万古霉素和喹诺酮类药物残留检测.     

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。     

分散液液微萃取在酸性模拟体系中塑料包装材料PAEs的溶出应用

将分散液液微萃取(DLLME)与气相色谱-氢火焰离子化检测器(GC-FID)技术相结合,建立了一种简单快速测定塑料包装材料在酸性模拟体系(体积分数为3%乙酸水溶液)中6种邻苯二甲酸酯(PAEs)溶出量的方法.采用四氯化碳作萃取荆,乙腈为分散剂,在优化条件下,6种PAEs在1.0～100.0μg/L质量浓度内呈良好的线性...     

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.     

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

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     

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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