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1.
在pH5.0~6.5条件下,汞(Ⅱ)与硫代米酮生成紫红色配合物,用732型强酸性阳离子树脂交换吸附进行树脂相分光光度法测定痕量汞(Ⅱ)。结果表明,有色配合物树脂相的最大吸收波长为590nm,汞(Ⅱ)含量在0~08mg·L-1范围内符合Beer定律,表观摩尔吸光系数为4.26×105L·mol-1·cm-1.用于黄河水中痕量汞(Ⅱ)的测定,相对标准偏差小于3.2%,加标回收率为95%~102%  相似文献   

2.
建立了气相色谱质谱法(GC-MS)快速检测酒类产品中邻苯二甲酸酯的方法.采用正己烷-甲基叔丁基醚(1∶1,v/v)作为萃取剂,Cleanert PEP Plus萃取小柱净化,GC-MS检测,外标法定量.利用该方法研究了17种邻苯二甲酸酯溶液在0.5~10 mg·L-1浓度范围的标准曲线,线性关系良好.利用优化后的方法测定了5个酒类样品中邻苯二甲酸酯的含量,在D类样品中分别添加浓度1 mg·L-1和2 mg·L-1的邻苯二甲酸酯混合标准工作液,回收率为78.2%~112.8%,相对标准偏差小于12.5%.  相似文献   

3.
膏状叶绿体中叶绿素总量的测定   总被引:1,自引:0,他引:1  
利用标准加入原子吸收分光光度法测定了膏状叶绿体中叶绿素的总含量.线性回归方程为c=3.766A-0.04665,线性相关系数R=0.9992,线性范围2.0000~3.2000mg·L-1.与文献报道的反相 萃取原子吸收分光光度法相比,该法具有操作简便、测定结果准确的优点.  相似文献   

4.
比较了水体中毒死蜱两种不同的萃取和测定方法。结果表明,石油醚萃取、紫外分光光度计测定方法简单、快速,适用于大量样品的初期筛选;乙酸乙酯萃取、HPLC(高效液相色谱)测定方法在精确度上高于紫外分光光度法,且能同时检测毒死蜱及其代谢产物TCP(3,5,6-三氯-2-吡啶醇)的含量,但其方法耗时、费力,适用于少量样品的精确测定。紫外分光光度法和HPLC法的最低检测浓度分别为0.1 mg.L-1和0.02 mg.L-1。  相似文献   

5.
建立了气相色谱质谱法(GC-MS)快速检测酒类产品中邻苯二甲酸酯的方法.采用正己烷-甲基叔丁基醚(1∶1,v/v)作为萃取剂,Cleanert PEP Plus萃取小柱净化,GC-MS检测,外标法定量.利用该方法研究了17种邻苯二甲酸酯溶液在0.510 mg·L-1浓度范围的标准曲线,线性关系良好.利用优化后的方法测定了5个酒类样品中邻苯二甲酸酯的含量,在D类样品中分别添加浓度1 mg·L-1和2 mg·L-1的邻苯二甲酸酯混合标准工作液,回收率为78.2%10 mg·L-1浓度范围的标准曲线,线性关系良好.利用优化后的方法测定了5个酒类样品中邻苯二甲酸酯的含量,在D类样品中分别添加浓度1 mg·L-1和2 mg·L-1的邻苯二甲酸酯混合标准工作液,回收率为78.2%112.8%,相对标准偏差小于12.5%.  相似文献   

6.
加替沙星的紫外、荧光分光光度法和高效液相色谱法测定   总被引:2,自引:0,他引:2  
采用紫外分光光度法、荧光分光光度法和反相高效液相色谱法测定胶囊中加替沙星含量. 在0.04 mol·L-1 HAc-NaAc缓冲溶液(pH=4.3)中直接根据加替沙星的紫外吸收光谱进行测定;于0.04 mol·L-1 HAc-NaAc缓冲溶液(pH=4.3)和0.014 mol·L-1十二烷基磺酸钠(SDS)体系中,以330 nm作为激发波长,在484 nm处测定其荧光强度;以VP-ODS为色谱柱(150 mm×4.6 mm, 5.0 μm), 柱温为35 ℃,流动相为V(CH3OH)∶V(H2O)=45∶55 (用醋酸调节pH至3.5), 流速为1.0 mL·min-1, 检测波长为292 nm,建立了测定加替沙星的反相高效液相色谱法. 3种方法对胶囊中加替沙星含量5次测定结果的平均值分别为98%,96%,102%, RSD分别为2.5%,2.7%,1.9%, 表明该方法可用于加替沙星制剂的质量控制.  相似文献   

7.
用多孔的ABS塑料管水平放置的方式保护静态液相微萃取的一滴溶剂,并由此建立了静态液相微萃取与高效液相色谱联用测定水体中甲基对硫磷和对硫磷的分析方法.考察了萃取溶剂、萃取溶剂体积、萃取时间以及搅拌速度对液相微萃取的影响,并对HPLC操作条件进行了优化.该方法对2种有机磷农药的线性范围均为0.05~1.00μg·L-1,相关系数R为0.999 3~0.999 5,回收率为95.2%~102%,相对标准偏差(n=7)3.5%~6.8%,检出限(3S/N)0.01μg·L-1.结果表明:用该方法测定水体中有机磷农药残留是可行的.  相似文献   

8.
钙-茜素S络合物体系在汞膜电极上的电化学行为及其应用   总被引:1,自引:0,他引:1  
在0.1 mol KOH介质中,用微分脉冲伏安法在汞膜玻碳电极上得到钙-茜素S络合吸附波,峰电位为-1.17V(vs.Ag-AgCl),峰电流与钙的浓度在5×10-8~4.2×10-5mol·L-1范围内呈良好的线性关系,检测限为2×10-8 mol·L-1.此络合波应用于血清中微量钙的测定,得到满意的结果.实验表明,该波为1:2的钙-茜素S的络合吸附波,还原过程为伴随两电子参与的不可逆电极反应.  相似文献   

9.
对变色酸分光光度法分析采气污水中甲醇含量的改进   总被引:1,自引:0,他引:1  
目前采气污水中甲醇含量的常用测定方法包括气相色谱法、变色酸分光光度法.其中变色酸分光光度法因设备简单,操作简便,在气田现场得到广泛应用.然而该法在甲醇浓度较高时,存在测定不准确、重现性差的问题.通过对变色酸分光光度法测定甲醇含量的实验条件优化,实现了高浓度甲醇废水的准确测定.结果表明:在最佳实验条件下,甲醇质量浓度在0~150 mg.L-1范围内线性关系良好(R=0.999 6),重现性好,准确度高,加标回收率为98.60%~104.30%,对现场含醇采气污水的测定结果与气相色谱法分析结果相符,完全满足高含醇采气污水的测定要求.  相似文献   

10.
采用紫外可见分光光度法测定污水中间-硝基苯酚的含量,结果表明间-硝基苯酚在以去离子水为溶剂、最大吸收波长为272nm的条件下,浓度在2mg/L~10mg/L范围内线性关系良好,得到其线性方程为A=0.040 2C+0.035 2,R2=0.999 8。结合线性回归方程可以计算出各地区污水中间-硝基苯酚的含量,并测得对各地区污水中间-硝基苯酚的平均回收率为97.7%,RSD小于0.39,由此说明采用紫外可见分光光度法测定各地区污水中间-硝基苯酚的含量具有操作简便,结果准确,灵敏度高的优点,在实际应用过程中可以做到降低检测成本,简化操作步骤,从而提高研究的工作效率。紫外可见分光光度法对各地区污水中间-硝基苯酚的含量测定,也为今后研究此类问题提供依据。  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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