首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
催化光度法测定痕量钴--Co(Ⅱ)-茜素红-溴酸钾体系   总被引:1,自引:0,他引:1  
研究了pH为8.0时的氨-氯化铵介质中,Co(Ⅱ)催化溴酸钾氧化茜素红褪色,建立了动力学光度法测定痕量Co(Ⅱ)的新方法.本方法检出限为4.4×10-6g/L,线性范围0~0.15mg/L,实测了天然水中痕量钴,结果满意.  相似文献   

2.
浊点萃取-荧光光度法测定废水中痕量铝   总被引:1,自引:0,他引:1  
建立了荧光光度法测定水中痕量铝离子的浊点萃取分离富集新体系.在pH=5.6的HAc-NaAc缓冲体系中,水样中的铝与8-羟基喹啉生成疏水性络合物.通过95 ℃水浴加热1.5 h,8-羟基喹啉-铝络合物被萃取到乳化剂(OP)表面活性剂相并与水相分开.在激发波长365 nm和发射波长510 nm下进行荧光测定,测定铝的线性范围为10.00~250.00 μg/L,方法的检出限(3σ)为0.39 μg/L,相对标准偏差(RSD)为3.6%,该法用于各种水样中痕量铝的测定,加标回收率为96%~105%,结果令人满意.  相似文献   

3.
基于亚硝酸根在酸性条件下对溴酸钾氧化偶氮胭脂红 B褪色的催化作用 ,建立了灵敏的催化光度测定痕量亚硝酸根的新方法 .测定线性范围为 :0~ 0 .5 ug/ m L,检出限 0 .10 ug/ m L 方法灵敏简便 ,选择性好 ,用于测定水中痕量亚硝酸根 ,结果满意 .  相似文献   

4.
利用微波消解法前处理样品,同时研究了在pH值为9.2的Na2B4O7-NaOH缓冲溶液介质中阳离子表面活性剂溴化十六烷基吡啶对Mn(Ⅱ)催化H2O2氧化二甲酚橙的褪色反应具有明显的增敏作用,建立了催化动力学光度法测定痕量Mn(Ⅱ)的新方法.该方法的线性范围为0.04~0.40μg/mL,检出限为0.009 6μg/mL.用于茶叶中微量锰(Ⅱ)的测定,回收率为98.3%~102.3%,结果令人满意.  相似文献   

5.
在磷酸介质中,痕量间苯二酚对高碘酸钾氧化吡咯红Y使其荧光猝灭具有抑制作用,据此建立了动力学荧光法测定痕量间苯二酚的新方法.方法的线性范围为3.0~45 ng/mL,检出限为1.2 ng/mL.用于测定合成样及药物中间苯二酚的含量,回收率为94.6%~104%.  相似文献   

6.
目的建立SDS胶束增敏光度法测定水中痕量CPs的新方法.方法研究了表面活性剂十二烷基硫酸钠(SDS)对H2O2-4-AAP-ST-H+-CPs体系光度法测定CPs的胶束增敏作用.以2,4-DCP为代表研究反应性能和条件.结果最大吸收波长为507nm,浓度线性范围为0.0226~0.626μg/mL,2,4-DCP检出限为6.78×10-10g/mL.相对标准偏差小于2.72%,样品加标回收率为96.81%~99.27%.结论新建方法操作简便,灵敏度高,选择性,检测费用低.结合C18柱固相萃取分离技术,该法应用于实际水样中CPs的测定,结果满意.  相似文献   

7.
研究了在盐酸介质中,铜(Ⅱ)催化过氧化氢氧化亚甲基蓝褪色反应的适宜条件与影响因素,建立了催化动力学光度法测定痕量铜的新方法.方法的线性范围为0~30.0×10-9g.mL-1,检出限为1.92×10-9g.mL-1,相对标准偏差为1.16%,标准加入回收率为98.5%~103.7%.该方法用于食品样品中铜的测定,获满意结果.  相似文献   

8.
本文利用Cu2 对2-水杨酰腙丙酸(SHPA)荧光的猝灭作用,建立了快速测定天然水中痕量铜的新方法。实验结果表明,在中性介质中,SHPA的荧光强度与Cu2 的浓度呈良好的线性关系,相关系数(r)为0.9974,Cu2 的检出限为0.36 μmol/L,线性范围为(0.7 – 9.3) μmol/L。本方法用于模拟天然水水样中Cu2 的测定,RSD = 2.41%。  相似文献   

9.
碱性(pH=9)条件下,在溴化十六烷基吡啶(CPB)存在下,水杨基荧光酮(SAF)可与Co(Ⅱ)发生显色反应,生成三元络合物,其最大吸收波长约在540nm处.据此,利用流动注射-胶束增溶分光光度法对饮用水中痕量Co(Ⅱ)进行测定,探讨SAF浓度、CPB质量浓度及缓冲溶液用量对光密度的影响,并对仪器的各项参数进行了优化.结果表明,在最优的实验条件下,该方法具有良好的选择性和抗干扰能力,其线性范围为3~40μg/L,线性方程为D=0.006 c+0.369 3,相关系数r=0.999 5.对15μg/L Co(Ⅱ)标准溶液进样11次的精密度为0.95%,在大约60样/h的采样频率下检出限为0.1μg/L,回收率为97.0%~104.3%.  相似文献   

10.
贾文平 《科学技术与工程》2011,11(34):8564-8566
利用Cu2+对2-水杨酰腙丙酸(SHPA)荧光的猝灭作用,建立了快速测定天然水中痕量铜的新方法。实验结果表明,在中性介质中,SHPA的荧光强度与Cu2+的浓度呈良好的线性关系,相关系数(r)为0.997 4,Cu2+的检出限为0.36μmol/L,线性范围为(0.7-9.3)μmol/L。本方法用于模拟天然水水样中Cu2+的测定,RSD=2.41%。  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.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号