气相色谱法测定韭菜中有机磷农药残留量

建立了毛细管气相色谱法、火焰光度检测器分析韭菜中的8种有机磷农药残留量的方法. 实验结果表明:采用程序升温所测定的8种有机磷农药,在色谱柱DB-608上分离良好,回收率在70%～119%之间;最低检测质量浓度分别为敌敌畏0.02μg·mL-1,甲胺磷0.01μg·mL-1,乙酰甲胺磷0.02μg·mL-1,甲拌磷0.01μg·mL-1,氧化乐果0.05μg·mL-1,乐果0.01μg·mL-1,甲基对硫磷0.01μg·mL-1,毒死蜱0.02μg·mL-1. 该方法快速灵敏,符合实际应用的需要.     

温控离子液体-分散液液微萃取分析环境水样中的有机磷农药

建立基于温控离子液体-分散液液微萃取和高效液相色谱-紫外检测联用的环境水样中痕量有机磷农药的分析检测方法.在优化的萃取条件下,不同环境水样中4种有机磷农药在2～500 μg·L-1浓度范围内具有良好的线性关系(R2＞0.994 3),检测限(s/n=3)为0.l～0.3μg·L-1,相对标准偏差为1.0％～6.3％;加...     

水产品中有机磷农药多残留的固相萃取-气相色谱串联质谱测定

通过比较不同的提取剂和吸附剂对水产品的净化效果和对质谱基线的影响,建立一种有效的水产品中有机磷农药多残留的气相色谱-三重四极杆串联质谱(GC-MS/MS)方法。用正己烷对样品进行提取处理,采用N-丙基二乙胺(PSA)和硅胶柱进行固相萃取,用GC-MS/MS多反应离子监测(MRM)模式测定。结果表明,在5～200μg·L-1范围内,28种有机磷农药的峰面积与对应的质量浓度间呈良好的线性关系,相关系数R20.996 8,方法的定量限(S/N=10)为0.2～7.9μg·kg-1,在大黄鱼中各农药的回收率为67%～99%之间,相对标准偏差(RSD)在5.3%～13.6%(n=6)之间,在南美白对虾中各农药的回收率为73%～106%之间,相对标准偏差(RSD)在4.6%～12.8%(n=6)之间。该方法较为灵敏、准确、简便,可用于检测水产品的有机磷农药残留情况。     

基于磁化原位离子液体分散液液微萃取测定天然椰子水中菊酯农药的含量

本研究建立了新型的超声辅助-Fe_3O_4磁性纳米粒子磁化-原位离子液体分散液液微萃取(UA-MISDLLME)法并结合高效液相色谱测定了天然椰子水中三种拟除虫菊酯农药的残留量.研究显示:萃取效率的影响因素包括离子液体的种类、离子液体的体积、离子交换剂的体积、Fe_3O_4磁性纳米粒子的用量、洗脱剂的种类以及超声时间等;三种拟除虫菊酯农药在0. 5～50 mg L~(-1)范围内呈现出良好的线性关系,相关系数为0. 999 4～0. 999 9,加标回收率为84. 8%～100. 6%,检测限为0. 034～0. 053 mg·L~(-1).结果表明,本方法适合于天然椰子水中三种菊酯农药残留量的检测,该方法中的超声辅助以及磁化原位交换反应简化和加快了样品前处理过程,并且绿色溶剂-离子液体种类的选择范围被进一步拓宽.     

HPLC法测定蒙药哈斯-哈图古日-15中没食子酸的含量

建立用HPLC法测定蒙药哈斯-哈图古日-15中没食子酸的方法.色谱柱为：Hypcrsil C18 ODS（4.6mmX250mm,5μL）,流动相为乙腈-水-磷酸（体积比为5：95：0.02）,流速为0.8 mL·min-1,检测波长为273nm,柱温为30℃.没食子酸在（0.40～1.2）mg·mL-1范围内线性关系良好（y=9E＋06x-127588,r=0.9999）,平均回收率94.95%（RSD=2.24%）.该方法可作为蒙药及蒙药材的没食子酸的含量测定方法.     

五味子中117种农药多残留气相色谱-串联质谱检测方法研究

建立了五味子中117种农药多残留气相色谱串联质谱（GC-MS／MS）检测方法。样品经乙酸乙酯-乙腈（30：70,v／v）超声振荡提取,凝胶渗透色谱技术（GPC）净化GC—MS／MS测定。117种农药在五味子样品中的最低定量限（LOQ,S／N=10）为0．005-0．2mg／kg。每种农药在五味子基质中,添加0．005-0．2mg／kg范围内（n=5）,回收率为62．1％～122．8％,相对标准偏差（RSD）为3．1%～17．8％。在0．01～5．0μg／mL的浓度范围内,各农药均具有良好线性。     

肾茶中有机氯农药残留的分析研究

建立了肾茶中8种有机氯农药残留的气相色谱分析方法.随机抽取样品,通过三种有机溶剂(石油醚、丙酮、乙醇)和三种提取方法(加热回流、索氏提取、超声提取)提取后,经浓硫酸磺化,用气相色谱法对有机氯农药残留进行定性定量分析.结果表明8种有机氯农药在1~250 ng·mL-1浓度范围内呈良好线性关系,平均加样回收率在79%~112%,相对标准偏差(RSD)小于10%.几种提取方法中以采用索氏提取法且乙醇为提取溶剂时提取率最高,所购肾茶样品中检测到γ-BHC和δ-BHC农药残留,但农药的检出量远低于《中国药典》中有机氯农药残留的标准.所建立的方法快速、准确、灵敏,适合肾茶中多种有机氯农药的检测.     

分散固相萃取-超高效液相色谱串联质谱法测定茶叶中的7种农药残留

以分散固相萃取技术为前处理手段,结合超高效液相色谱串联质谱法,建立一种快速检测茶叶中7种农药残留的方法.茶叶样品经前处理后,采用UPLC-MS/MS法检测分析.用空白样品提取液配制基质工作曲线,外标法定量.结果表明,多菌灵、丁醚脲、喹螨醚在0.1~2.0、灭多威在1.0~20.0、噻虫嗪、吡虫啉、噻螨酮在2.0~40.0 ng·m L-1的范围内具有良好的线性关系,其检出限为0.10~5.00μg·kg-1.平均加标回收率为75.9%~116.8%,相对标准偏差为2.6%~6.1%.该方法简便、可靠、稳定,可用于茶叶中多种农药残留的快速检测与确证.     

原料奶中5种阴离子的离子色谱分析

为了建立原料奶中5种阴离子(Cl-,NO3-,HPO42-,SO42-,SCN-)的离子色谱检测方法,将原料奶经乙腈沉淀蛋白质后离心过滤处理进行离子色谱检测.色谱条件,淋洗液:NaHCO3(1.0mmol/L),Na2CO3(3.2mmol/L),体积分数为15%的丙酮超纯水混合液.流速为1.0mL/min,检测器为电导检测器.该方法对5种离子的电导检出限均为0.02mg/L.在线性范围内r=0.997 6及以上.5种离子的精密度RSD为0.08%～9.58%,各阴离子的回收率均为80%～120%,变异系数在10%以内.该方法具有方便、准确、成本低的优点.     

六种中药材中的有机氯农药残留量的测定

用气相色谱法同时测定了中药材天仙子、半夏、杜仲、吴茱萸、何首乌、茯苓中的有机氯农药的残留量.结果表明,13种有机氯农药在1~100μg/L范围内线性关系良好(r>0.995 5),检出限为0.04~0.22μg/L,添加回收率均在80%~102%.该方法符合农药残留检测标准.     

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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