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1.
胶束增敏荧光光谱法测定吡哌酸   总被引:4,自引:0,他引:4  
采用不同表面活性剂对吡哌酸在胶束体系中的荧光性质进行了研究,发现在酸性介质中十二烷基硫酸钠(SDS)对吡哌酸有较强的增敏作用,据此建立了胶束增敏荧光光谱法测定吡哌酸的新方法。方法线性范围为0.07-0.36μg/mL,检出限为0.04μg/mL,平均回收率为98.6%-101.3%,相对标准偏差为1.1%-1.2%。样品测定结果令人满意。  相似文献   

2.
研究了恩诺沙星(EFLX)在胶束体系中的荧光特性,发现十二烷基硫酸钠(SDS)对EFLX有较强的增敏作用,据此建立了胶束增敏荧光光谱法测定恩诺沙星的新方法。方法的线性范围为0-0.64μg/mL,检出限为4.75 ng/mL。  相似文献   

3.
研究了洛美沙星在胶束中的荧光特性,发现十二烷基磺酸钠(SDS)对洛美沙星的荧光有较强的增敏作用。据此,提出了胶束增敏荧光光谱法测定痕量洛美沙星的新方法,洛美沙星含量在0.04~4μg/mL范围内与其荧光强度线性关系良好,相关系数r=0.9995。方法的平均回收率为96.2%~100.8%。  相似文献   

4.
采用不同的表面活性剂对Cu(Ⅱ)与头孢羟氨苄生成的配合物在胶束体系中的荧光性质进行了研究,发现在pH6.2的Tris缓冲溶液中阴离子表面活性剂十二烷基硫酸钠对其配合物的荧光有显著的增敏作用,据此建立了胶束增敏荧光光谱法测定头孢羟氨苄的新方法。在最佳实验条件下其线性范围为0.03~1.14μg/mL,检出限为0.03μg/mL,经实际样品测定,其平均回收率为97.3%~101.4%,相对标准偏差为1.1%~1.3%。  相似文献   

5.
文志明  王怀公 《化学学报》1990,48(3):256-261
本文研究了在各种类型的表面活性剂存在下, 钯与柠檬黄的胶束增敏荧光反应, 测定了金属荧光配合物的形成条件、组成、量子产率、表观稳定常数和激发波长处的摩尔吸光系数, 对胶束增敏作用机理进行了初步探讨. 确定了测定钯的最佳条件, 钯在0.1-8.0μg/25mL 范围内与荧光强度呈线性关系, 检出下限达8.0x10^-^4μg/mL. 本文方法可不经分离直接快速地测定贵金属矿样中痕量钯,结果令人满意。  相似文献   

6.
研究了在pH2.5的HCI-NaAc介质中,溴化十六烷基三甲铵(CTMAB)对桑色素(morin)和钒(V)配合物荧光的增敏作用,建立了利用钒(V-morion-CTMAB胶束增敏荧光反应测定痕量钒的荧光光度新方法。方法的检出限为0.92μg/L,荧光强度与钒的含量在0.010-6.0μg/10mL范围内呈线性关系,配合物中钒(V)与桑色素的组成比为:V(V):morin=1:1。方法可应用于天然水和食品中微量钒的测定。  相似文献   

7.
荧光分析法测定荜茇有效成分荜茇宁   总被引:1,自引:0,他引:1  
根据荜茇有效成分荜茇宁的荧光被表面活性剂OP-10显著增敏的特征,提出了胶束增敏荧光法测定蒙药荜茇中荜茇宁的荧光分析新方法.荜茇宁的含量在2.0~16.0μg/mL范围内,与其荧光强度呈良好的线性关系,相关系数为0.9992,方法的回收率为96.9%~104.5%.此方法适合蒙药荜茇中荜茇宁的测定.  相似文献   

8.
司帕沙星金属络合物在胶束体系中的荧光特性研究及应用   总被引:19,自引:0,他引:19  
杜黎明  晋卫军  董川  郑台 《分析化学》2000,28(4):403-406
研究了在金属离子存在下司帕沙星在胶束体系中的荧光特性,首次发现锌(Ⅱ)和阴离子表面活性剂十二烷基硫酸钠对司帕沙星的荧光有显著的协同增敏作用,据引建立了测定人体尿液中司帕沙星含量的同步-导数荧光光谱法,定量线性范围为0.04~4.0mg/L,检测限为0.04mg/L。相对标准偏差为1.6%~3.9%。探讨了锌(Ⅱ)和十二烷基硫酸钠对司帕沙星荧光的增敏机理。  相似文献   

9.
本文研究了胶束介质对邻苯二胺的酶催化氧化产物2,3-二氨基吩嗪的光谱性质的影响,发现胶束介质对其吸收光谱影响很小,非离子表面活性剂对其荧光具有强烈的增敏作用,荧光量子效率可提高近十倍。进一步研究表明,非离子表面活性剂对2,3-二氨基吩嗪的增敏原因在于其增溶作用及给电子效应。  相似文献   

10.
反相胶束介质对2,3-二氨基吩嗪的荧光增敏作用研究   总被引:5,自引:0,他引:5  
研究了反相胶束介质丁二酸双(2-乙基己基)酯磺酸钠(AOT)/正辛烷对漆酶催化氧化邻苯二胺的产物2,3-二氨基吩嗪(DAP)光谱性质的影响。试验表明,AOT/n-octane对DAP吸光性质稍有增敏作用,而对其荧光具有强烈的增敏作用,使DAP荧光量子产率提高近30倍,并进一步研究了微环境对荧光性质的影响和反相胶束介质AOT/n-octane对DAP荧光的增敏机理。  相似文献   

11.
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   

12.
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   

13.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.

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   

16.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  相似文献   

17.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

18.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

19.
20.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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