高效液相色谱衍生法测定水产品中甲醛的残留量

建立了水产品中甲醛残留量的高效液相色谱分析的方法。样品经缓存溶液提取、衍生化后,以正己烷萃取,氮吹浓缩,利用高效液相色谱分析。在1.0～5.0mg/kg添加水平,回收率在88.2%～95.3%之间,变异系数在6.5%～7.9%之间。以S/N=3计算,方法检出低限为0.4mg/kg。结果表明,该法简便、灵敏、准确,适用于水产品中甲醛残留量的分析。     

免疫亲和-填充吸附微萃取和液相色谱-串联质谱法测定牛奶中己烯雌酚#br#

基于免疫亲和-填充吸附微萃取（immunoaffinity microextraction by packed sorbent, IA-MEPS）净化，建立了一种快速简便、环境友好的牛奶中己烯雌酚的液相色谱-串联质谱检测方法. 将己烯雌酚单克隆抗体与二氧化硅玻璃微珠偶联，制备可重复使用的IA-MEPS 注射器，优化了萃取时间、萃取速率、解吸溶液、解吸时间等重要参数. 进一步建立了以IA-MEPS 为净化手段的LC-MS/MS 分析方法，用于牛奶中己烯雌酚残留量的测定. 己烯雌酚的动态柱容量为974 ng/0.2 g 玻璃珠，重复使用15 次后，柱容量仍能达到初始柱容量的45%. 在3个添加浓度水平，己烯雌酚的平均回收率为75.5%-78.9%，日内变异系数小于7.7%，日间变异系数为小于6.7%，方法的检测限为0.1 ng/g，定量限为0.5 ng/g. 该方法操作简单、灵敏度高、选择性好，可以满足定量分析牛奶中己烯雌酚的需要.     

高效液相色谱法同时测定禽肉中磺胺类药物残留方法的研究

本方法研究了用固相萃取-高效液相色谱法同时测定禽肉中7种磺胺类药物残留量的方法。样品经乙睛超声提取,过碱性氧化铝SPE柱净化,用乙腈洗脱用磷酸定容,试液供反相高效液相色谱-紫外检测器测定。检测波长为270nm,柱温40℃,流动相:磷酸水溶液-乙腈梯度洗脱,7种组分的回收率在88.5%~101.2%之间,本方法前处理简单,梯度洗脱分离效果和重现性好,方法快速、灵敏、可用于禽肉中磺胺类药物残留量的常规检测。     

不同柱后衍生温度检测麻痹性贝毒的高效液相色谱方法研究

采用高效液相色谱分析并结合柱后衍生法，以不同的衍生温度对麻痹性贝毒的检测方法进行比较和优化，并对来自环境和实验室培养的赤潮藻样品进行检测．结果表明：检测PSP最适的柱后衍生温度为80℃；对实验室纯培养的赤潮藻东海原甲藻未能检测出毒素，对塔玛亚历山大藻CI01(ATCI01)则比较容易地检测出了C毒素和GTX2、GTX3、GTX5等毒素，而对厦门港赤潮水样的裸甲藻虽能检测出毒素，但不属于PSP类的毒素，提示此方法能对PSP毒素进行有效地检测．     

基于DNFB柱前衍生和反相高效液相色谱(RP-HPLC)方法的葡萄酒氨基酸检测的研究

文章首先对反相高效液相色谱(RP-HPLC)的基本介绍理论进行了介绍和比较,回顾了以往学者在不同学科检验中对于DNFB柱前衍生和反相高效液相色谱(RP-HPLC)方法的应用。最后通过该方法对市面销售的两种葡萄酒的进行了相关的检测。     

GC-MS/MS法测定虾仁中氯霉素残留的研究

样品经过有机溶剂溶解、均质、离心、净化、衍生化后,在一定的色谱及质谱条件下分别用电子轰击电离全扫描方式和GC-MS/MS测定其样品中氯霉素残留量,其检测限为0.2 ng/g,加标回收范围为85.37%～102.79%.研究表明,该方法具有较高的灵敏度和较低的检测限,符合对虾仁中氯霉素残留量检测限的要求.     

SPE-HPLC/UV法同时检测牛奶中5种三嗪类除草剂的残留

建立了同时检测牛奶中残留的5种三嗪类除草剂的高效液相色谱法。实验使用不同的固相萃取柱(C18、LiChrolut EN)对目标物进行富集,以乙腈和磷酸盐缓冲溶液(pH=7.4)为流动相,在1.2 mL/min的流速、220 nm的紫外检测波长下进行高效液相色谱分析。结果表明,其检测限和量化限分别为0.13、0.38μg/L,回收率为62.2%~95.1%,精密度为2.3%~10.5%,线性关系非常好,r2(0.9970,且分析步骤易于程序化,可以满足牛奶中三嗪多残留检验工作的需要。     

高效液相色谱-柱后衍生荧光法同时检测粮食中8种氨基甲酸酯类农药

建立了高效液相色谱-柱后衍生荧光法同时检测粮食中8种氨基甲酸酯类农药,样品经乙腈提取,SPE-NH2小柱净化,减压旋转蒸发浓缩后定容.检测系统为柱后光化学衍生器串联荧光检测器,激发波长330 nm,发射波长465 nm.外标法定量,方法的线性范围为0.01～1.00 mg·L-1,检出限(3S/N)为3～5 μg·kg...     

RP—HPLC紫外检测法在糖类化合物分离中的应用

应用柱前衍生技术和反相高效液相色谱法（HPLC），紫外检测分离果糖、葡萄糖、肌醇、半乳糖醇和山梨醇、获得良好分离结果。     

液相色谱/质谱法测定生鲜牛奶中的两种氨基甲酸酯农药残留

建立了高效液相色谱-质谱法同时测定生鲜牛奶中杀线威、涕灭威残留量的方法。样品用乙酸乙酯提取,C18固相萃取柱纯化、富集,采用电喷雾正离子模式离子化。在质谱图中,[M Na] 强度最大,定量测定使用多离子监测模式m/z:242→72,213→116。杀线威、涕灭威的检测限分别为0.4 ng、0.1 ng,方法的平均回收率:杀线威为92.5%~95.6%、涕灭威为91.6%~93.4%。方法的灵敏度高,选择性好。用于实际样品的分析,获得满意的效果。     

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     

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