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1.
meso-四(对-磺酸基苯基)卟啉与痕量铋(Ⅲ)显色反应的研究   总被引:2,自引:0,他引:2  
本文研究了在催化剂Hg(Ⅱ)存在下,meso-四(对-磺酸基苯基)卟啉与铋(Ⅲ)的显色反应。在室温下,在弱酸性介质中,反应在7min内完成。配合物的最大吸收波长为462nm,表观摩尔吸光系数为3.78×10~5L·mol~(-1)·cm~(-1)。Bi(Ⅲ)含量在0~10μg/mL范围内符合比尔定律。配合物的组成为Bi(Ⅲ):TPPS_4=2:3。是目前测定Bi(Ⅲ)灵敏度最高的显色反应之一。用于矿样中痕量铋(Ⅲ)的测定获得了较为满意的结果。  相似文献   

2.
本文报道铋(Ⅲ)与不对称变色酸双偶氮衍生物之间的一类特殊反应——β型反应。研究了试剂分子结构与反应性能的关系,着重探讨铋(Ⅲ)与偶氮氯膦-p~N的β型反应行为。在高氯酸介质中,铋(Ⅲ)与上述试剂形成灵敏度很高的稳定β型配合物,λ_(max)=713nm,ε(max)=9.84×10~4L·mol~(-1)·cm~(-1)。并考察了反应酸度、显色剂浓度、有机溶剂(或表面活性剂)、显色温度及显色时间等对反应的影响,测定了α和β型配合物的组成,初步探索了α和β型配合物之间相互转化的规律。  相似文献   

3.
对5种新的偶氮氟膦型试剂与铋(Ⅲ)的显色反应的条件进行了研究,考察了反应酸度、配合物的最大吸收峰的位置、配合物的稳定性、反应灵敏度及选择性等,结果表明:5种偶氮氟膦型试剂与铋配合物的最大吸收波长位于622~664nm之间,摩尔吸光系数在(0.72~0.98)×105L·mol-1·cm-1范围内。方法已用于实际样品胃必治中铋的测定。  相似文献   

4.
在阳离子表面活性剂CTMAB存在下,研究了DB-o-NPF与Ge(Ⅳ)的显色反应.试验表明,在磷酸介质中,Ge(Ⅳ)与DB-o-NPF形成1:2稳定的红色配合物.该配合物最大吸收波长为550nm,其表观摩尔吸光系数为1.04×105L@mol-1@cm-1.锗量在0~6μg/25ml范围内符合比耳定律.试验结果表明,Ge(Ⅳ)-DB-o-NPF-CTMAB体系显色测定Ge(Ⅳ),很多离子不干扰测定.方法灵敏度高,选择性好,有色配合物稳定48h以上.直接用于烟道灰中微量锗的测定,结果满意.  相似文献   

5.
研究了新显色剂 5 (对羧基苯偶氮 ) 8 羟基喹啉 (5 CPAHQ)在阳离子表面活性剂十六烷基三甲基溴化铵 (CTMBA)存在下 ,与铁 (Ⅲ )的显色反应条件。试验结果表明 ,在pH 4 .2~ 5 .6范围内 ,该显色剂可与铁 (Ⅲ )形成 1∶6稳定的红色配合物。在 4 4 8nm波长处配合物的表观摩尔吸光系数为 4 .14× 10 4 L·mol- 1·cm- 1,该法用于力勃隆药片和大黄中铁的测定 ,结果满意  相似文献   

6.
研究结果证实,用偶氮氯膦Ⅲ(CPAⅢ)以β型配合物测定钇时,镧的干扰属于一种共显色效应。共显色效应的实质,可能是形成了一种具有环状结构的镧-偶氮氯膦Ⅲ-钇的混合多核配合物。配合物中各组分的比例为La∶CPAⅢ:Y=1∶2∶1。本文还讨论了混合多核配合物生成的有关条件和各种影响因素。提出了“置换型”共显色效应的设想。  相似文献   

7.
二溴硝基偶氮氯膦与铝显色反应的研究及应用   总被引:3,自引:0,他引:3  
研究了在pH4.8乙酸盐介质中,Al(Ⅲ)与DBNCPA的显色反应.该配合物的最大吸收波长位于620nm,摩尔吸光系数∈_(620)为3.6×10~4,AI(Ⅲ)含量在0~14μg/25ml范围内符合比耳定律.方法具有较好的选择性,用于人发、食物中微量铝的测定,结果满意.  相似文献   

8.
本文报道了三溴偶氮溴膦(4-BPA-TB)与Bi(Ⅲ)的显色反应.研究结果表明:在高氯酸介质中,乙醇存在下,该试剂与Bi(Ⅲ)形成稳定的蓝紫色配合物,配合比为1:2,其最大吸收波长为644nm,表观摩尔吸光系数为1.0×10~5,Bi(Ⅲ)0~20μg/25ml范围内符合比耳定律.将该方法用于铸铁及紫铜样品中微量铋的测定,获得了满意的结果.  相似文献   

9.
在阳离子表面活性剂 CTMAB存在下 ,研究了 DB- o- NPF与 Ge( )的显色反应。试验表明 ,在磷酸介质中 ,Ge( )与 DB- o- NPF形成 1∶ 2稳定的红色配合物。该配合物最大吸收波长为 550 nm,其表观摩尔吸光系数为 1 .0 4× 1 0 5L·mol-1·cm-1。锗量在 0~ 6μg/2 5ml范围内符合比耳定律。试验结果表明 ,Ge( ) - DB- o- NPF- CTMAB体系显色测定 Ge( ) ,很多离子不干扰测定。方法灵敏度高 ,选择性好 ,有色配合物稳定 48h以上。直接用于烟道灰中微量锗的测定 ,结果满意。  相似文献   

10.
偶氮氯膦—mA与Fe(Ⅲ)显色反应的研究及其应用   总被引:4,自引:0,他引:4  
研究了偶氮氯膦-mA与Fe(Ⅲ)的显色反应及条件。在pH=1的介质中,Fe(Ⅲ)与偶氮氯膦-mA形成稳定的1:2的配合物,其表观摩尔吸光系数,为2.23×10~4,最大吸收波长为680nm,Fe(Ⅲ)量在0~40μg/25ml范围内符合比耳定律。结合沉淀分离,用于铜合金中微量铁的测定,效果好。  相似文献   

11.
利用手持技术改进测定乙醇分子结构实验   总被引:1,自引:0,他引:1  
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。  相似文献   

12.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.  相似文献   

13.
14.
由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。  相似文献   

15.
The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.  相似文献   

16.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

17.
实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。  相似文献   

18.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

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19.
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.  相似文献   

20.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

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