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1.
一种日常快速分析食物中毒样品中有机磷农药的方法   总被引:1,自引:0,他引:1  
采用0.53mm宽口径毛细管柱,在带氮磷检测器(NPD)的气相色谱上一次快速测定多种有机磷(OP)农药,结果表明,当添加OP农药水平在0.12mg/kg-0.70mg/kg时,7种OP农药的回收率范围为78.8%-101.2%,变异系数3.4%-8.2%,方法检测限达1.1μg/kg-6.3μg/kg。无水硫酸钠对提高OP农药以提取过程中的回收率有重要作用。  相似文献   

2.
单柱离子色谱法同时测定土壤中溴和碘的研究   总被引:3,自引:0,他引:3  
本文研究了以邻苯二甲酸/三羟甲基氨基甲烷为淋洗液的单柱离子色谱法同时测定土壤中微量溴和碘离子的方法。样品采用碳酸钠-氧化镁混合熔剂半熔,热水浸提,无基体干扰。淋洗液最佳浓度为2.2mmol.L^-1,H2C8H4O4/2.0mmol.L^-1H2NC(CH2OH)3。最低检测限Br^-0.065μg/ml.I^-0.027μg/ml。相对标准偏差Br^-,1.96%,I^-3.17%,回收率Br^  相似文献   

3.
气相色谱法测定发酵食品中的游离乳酸   总被引:1,自引:0,他引:1  
采用气相色谱法单独对发酵方法生产的食品中含有的游离乳酸进行了测定研究,用FID检测器检测。方法的平均标准差为0.082-1.81,变异系数为2.6%-6.2%,平均回收率为98.1%-102.2%。  相似文献   

4.
单柱离子色谱法测定饮用水,井水和矿泉水中微量硫酸根   总被引:1,自引:0,他引:1  
本文研究了单柱离子色谱法测定饮用水、井水和矿泉水中微量硫酸根的方法。样品经适当稀释,微孔滤膜过滤即可直接进样分析。淋洗液最佳浓度为2.6mmol·L^-1H2C8H4O4/2.5mml·L^-1H2NC(CH2OH)3。电导检测器检测、检测灵敏度为1.6μs/cm。最低检出限为0.15μg/ml,线性范围1.0 ̄2.5×10^3μg/ml,相对标准偏差1.5%,平均回收率97.66 ̄98.77%。  相似文献   

5.
使用反外HPLC法测定3H状元胶囊中的1α-羟基维生素D3,固定相为C18,流动相为乙腈:水(97:3),测定波长为265nm标样线性范围为0.1~1.0μg/mL(r=0.9988,n=5)最低检出率为0.5ng,天内天间精密度分别为1.41%(n=10)和2.72%(n=3)平均回收率为99.1%(RSD=2.78%),该方法用于测定3H求元胶囊的1α-羟基维生素D3,取得较满意的结果。  相似文献   

6.
探讨了1-硝基蒽醌(1-NO_2AQ)和1-氨基蒽醌(1-NH_2AQ)同时测定和分别测定的色谱条件,提出了在Shim-packCLSS-SIL色谱柱上,以正庚烷-1,4二氧六环-乙酸乙酯(65:35:5(V/V)为流动相,流量为1.5ml/min,柱温40℃,以分光光度检测器于254nm处检测时,4min内使1-NO_2AQ与1-NH_2AQ分离;5min使1-NH_2AQ与杂质分离;7min可使1-NO_2AQ与杂质分离的高效液相色谱分析法。其绝对检出下限1-NO_2AQ为0.012μg,1-NH_2AQ为0.026μg,变异系数分别为1.1%和0.96%,回收率分别为99.7%和100.2%。  相似文献   

7.
生长调节物质对丹参叶片脱分化及根芽分化的效应   总被引:11,自引:1,他引:11  
生长调节物质对丹参叶片脱分化及根芽分化效应的研究结果表明:(1)0.5~5.0mg/L2,4-D,0.1~0.5mg/LNAA0.5~1.5mg/LIBA或0.2~1.0mg/L4PU-30诱导叶片的脱分化率高达97%~1000%。(2)0.1~0.5mg/LNAA或0.5~2.0mg/IBA诱导芽化率为93%~100%,3种细胞分裂素中,4PU-30对叶片芽化最有效,6-BA和KT次之。(3)随  相似文献   

8.
β—环糊精的溶胶一凝胶法电色谱开管柱的制备及评价   总被引:2,自引:0,他引:2  
首次以溶胶-凝胶(Sol-gel)方法制备了2,6-二丁基β-环糊精(β-TB-CD)毛细管电色谱开管柱。以苯胺,苯酚和苯甲酸混合体系对其进行了评价,获得的柱效分别为2.837×10^4,4.531×10^4,7.635×10^4理论塔板数/m,保留时间和峰面积的RSD分别为1.64%,1.15%,2.07%和6.02%,7.02%。结果令人满意。  相似文献   

9.
极谱吸附波连续测定水样中痕量锌,锰和硒   总被引:4,自引:0,他引:4  
在酒石酸-乙二胺-高氨酸-亚硫酸钠-高碘酸钟体系中痕量锌锰和硒出现良好极谱吸附波,波峰敏锐,可测定浓度范围在0.40~40μg/L Zn ̄(2+)1.6~80μg/LMn ̄(2+)及0.02~2.3μg/LSe(Ⅳ)。对含11.7μg/L Zn ̄(2+),7.0μg/L Mn,1.45μg/L Se(Ⅳ)的矿泉水样测定,其相对标准偏差分别是6.2%和9.2%和7.3%。  相似文献   

10.
利用Leuckart反应,以55%~85%的产率由酮与甲酸铵反应制得了5种外消旋胺;并用(+)-酒石酸为析解剂、以甲醇和甲醇/乙酸乙酯作重结晶溶剂,以好的产率分别把(±)-4-苯基-2-丁胺和(±)-1-苯基-2-甲基丙胺拆分得到它们的光学异构体.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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。  相似文献   

14.
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.  相似文献   

15.
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-  相似文献   

16.
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-  相似文献   

17.
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  相似文献   

18.
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  相似文献   

19.
<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  相似文献   

20.
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