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1.
本文研究了阳离子、阴离子及非离子型表面活性剂对铟-水杨基萤光酮络合反应的胶束增敏作用的适宜pH范围和吸收光谱特性,并对其增敏机理进行探讨。试验表明溴化十六烷基三甲基铵(CTMAB)增敏作用最强,摩尔吸光系数可达1.8×10~5,pH范围宽。并考察了四十多种离子对反应的影响。拟定测定微量铟的方法,可不用有机溶剂萃取,对环境保护有利。  相似文献   

2.
磷酸盐缓冲的中性溴化十六烷基三甲基铵-正戊醇-正庚烷微乳液介质体系对鲁米诺的电化学发光有显著的增敏作用,本文对此增敏作用进行了研究,并在此介质体系中采用电化学发光淬灭法测定了生物活性分子褪黑素,此法可用于测定脑白金胶囊中的褪黑素。  相似文献   

3.
自六十年代起,阳离子表面活性剂用于分光光度法中以来,胶束增溶分光光度法的研究甚多,但是,阳离子表面活性剂用于偶氮染料——金属离子测定体系产生真正的增敏作用的例子并不多见。至于把非离子表面活性剂用于偶氮染料——金属离子测定体系而产生增敏作用的情况也很少。我们仅见用氯化十四烷基二甲基苄基铵-(口底)唑测定铝以及吐温-80-(口底)唑测定铝的报告。此外,测定镉的胶束增溶分光光度法也甚少见报道。本法用吐温  相似文献   

4.
沈含熙  王连生 《化学学报》1983,41(8):700-708
本文研究了八种2,3,7-三羟基-9-取代荧光酮在阳离子表面活性剂存在下与锗的胶束增敏显色反应.发现水杨基萤光酮及邻硝基苯基萤光酮在强酸性介质中可以和溴化十六烷基三甲基铵形成高灵敏的胶束三元配合物.较详细地研究了用邻硝基苯基萤光酮与溴化十六烷基三甲基铵分光光度法测定微量锗的实验条件.并探讨了有关配合物的组成以及胶束增敏反应的机理.此法可不经分离,直接快速测定铅锌矿中的微量锗,结果比较满意.  相似文献   

5.
卟啉胶束增敏导数分光光度法测定微量锰   总被引:1,自引:0,他引:1  
卟啉的分子截面积大,与一些金属离子配合都具有很高的摩尔吸光值,已被称之为“超高灵敏度的显色剂”。文献研究了在阳离子表面活性剂存在下,锰与阴离子卟啉的增敏反应,本文在阴离子表面活性剂存在下,采用导数光度法,探讨的锰与阳离子卟啉的增敏作用。试验表明,试液中无论是单体还是胶束对锰与阳离子卟啉生成的Mn-T(4-TAP)P二元配合物均有增敏作用,最大吸收波长紫移。  相似文献   

6.
本文研究了16种表面活性剂对铽-铜铁试剂-氯化铵极谱体系的增敏作用。实验结果表明,除阳离子表面活性剂、长链烷基吡啶以及在溶液中不能形成“胶束”的表面活性剂外,其它的阳离子表面活性剂、非离子表面活性剂和两性表面活性剂均能对上述体系产生增敏作用。氯化十二烷基三甲铵(DTMAC)的增敏作用最强。利用示波导数极谱测定铽的最佳条件为:0.03MNH_4Cl-0.08%铜铁试剂(Cup)-0.005%DTMAC-O.1%NH_4OH,pH~9.铽浓度在4.4×10~(-10)M~4.4×1O~(-9)M之间与波高成线性关系。干扰元素经萃取和色谱分离后,本方法可成功地用于矿石中痕量铽的测定。  相似文献   

7.
苯基荧光酮类化合物化学发光反应的基团效应   总被引:1,自引:0,他引:1  
本文采用流动注射-化学发光分析方法,研究了苯基荧光酮及其六种衍生物的化学发光行为。发现它们在碱性条件下可以被过氧化氢氧化而产生化学发光。金属离子Co(Ⅱ)对这些化学发光反应有较强的催化作用。阳离子表面活性剂溴化十六烷基三甲基铵(CTMAB)有增敏作用。  相似文献   

8.
研究了Ca2+和阳离子表面活性剂CTMAB对四环素(TC)的荧光增敏作用,提出了一种利用Ca2+-TC-CTMAB三元配合物协同增敏体系来测定TC含量的新方法.在Ca2+-CTMAB及TC共存体系中,由于三元配合物的生成使TC的荧光强度急剧增加,其荧光强度与TC浓度在8.0×109-9~1.0×10-5 mol/L范围内具有良好的线性关系,方法检出限为5.97×10-9 mol/L.该法用于TC片剂、尿液及牛奶中残留TC的测定,加标回收率为82.4%~98.3%.同时对TC在不同介质中的荧光增敏作用机理进行了初步探讨.  相似文献   

9.
研究了以钴对鲁米诺桑色素 (LAM)氧化的催化反应作为指示反应的测定痕量钴的新方法及表面活性剂对该催化反应的增敏作用。LAM在碱性条件下被H2 O2 氧化褪色 ,钴对该氧化反应有强烈的催化作用。阳离子表面活性剂 ,如CTMAB对此催化反应有较强的增敏作用 ,可将灵敏度提高 4倍。据此建立了测定痕量钴的催化动力学新方法 ,并测定了该催化反应的动力学参数 ,以探讨表面活性剂增敏的机理。方法的检出限为 7.5ng/mL ,相对标准偏差为 4× 1 0 - 3%。用该法测定了维生素B1 2 中钴的质量分数 ,与原子吸收测定结果十分吻合。  相似文献   

10.
在PH=4.8的HAc-NaAc缓冲溶液中,基于表面活性剂十六烷基三甲基溴化胺对色氨酸催化高碘酸钾氧化罗丹明B的褪色反应有较强的增敏作用,建立了测定色氨酸的表面活性剂增敏催化动力学荧光新方法.研究了反应的适宜条件及动力学参数.在优化实验条件下,色氨酸浓度在3.0-25.0 mg/L范围内与荧光强度呈良好线性关系,回归方...  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.
13.
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   

14.
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   

15.
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   

16.

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.

  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 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   

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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