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1.
联吡唑啉类化合物的合成及其荧光性能 总被引:2,自引:0,他引:2
以1-苯基-3-甲基-5-苯氧基-吡唑-4-甲醛为原料,与苯乙酮(取代苯乙酮)发生羟醛缩合,生成相应的查尔酮,再在冰醋酸中与不同的肼反应,高产率的合成出10种新的5位含1-苯基-3-甲基-5-苯氧基-吡唑基的吡唑啉类衍生物。冰乙酸既是反应溶剂,又是催化剂,产率最高可达72%。目标化合物的结构经元素分析、红外光谱和核磁共振测试技术加以确认。化合物的荧光测定证明,化合物3a~3e发射紫色荧光,λem约为377 nm,化合物4a~4e发射蓝色荧光,λem约为480 nm。在荧光光谱中,不同取代基的联吡唑啉类化合物表现出不同的荧光强度,其中化合物4e具有最强的荧光发射,其强度值可达到4694。所合成出的化合物是一类较好的联吡唑啉类荧光化合物。 相似文献
2.
The combination of remote/standoff sensing and laser-induced fluorescence (LIF) spectroscopy shows potential for detection of uranyl (UO2(2+)) compounds. Uranyl compounds exhibit characteristic emission in the 450-600 nm (22,200 to 16,700 cm(-1)) spectral region when excited by wavelengths in the ultraviolet or in the short-wavelength portion of the visible spectrum. We report a parametric study of the effects of excitation wavelength [including 532 nm (18,797 cm(-1)), 355 nm (28,169 cm(-1)), and 266 nm (37,594 cm(-1))] and excitation laser power on solid-state uranium compounds. The uranium compounds investigated include uranyl nitrate, uranyl sulfate, uranyl oxalate, uranium dioxide, triuranium octaoxide, uranyl acetate, uranyl formate, zinc uranyl acetate, and uranyl phosphate. We observed the characteristic uranyl fluorescence spectrum from the uranium compounds except for uranium oxide compounds (which do not contain the uranyl moiety) and for uranyl formate, which has a low fluorescence quantum yield. Relative uranyl fluorescence intensity is greatest for 355 nm excitation, and the order of decreasing fluorescence intensity with excitation wavelength (relative intensity/laser output) is 355 nm > 266 nm > 532 nm. For 532 nm excitation, the emission spectrum is produced by two-photon excitation. Uranyl fluorescence intensity increases linearly with increasing laser power, but the rate of fluorescence intensity increase is different for different emission bands. 相似文献
3.
A high-performance liquid chromatographic method was developed to measure the concentration of brodimoprim and its metabolite, hydroxybrodimoprim, in small volumes of blood, plasma and urine. The procedure involved a simple extraction step with chloroform, followed by chromatographic separation on a short reversed-phase column deactivated for the analysis of basic compounds. The column effluent was monitored by fluorescence (excitation wavelength 290 nm, emission wavelength 340 nm). The recoveries of both compounds were similar in all three biological fluids, and averaged 84 and 72%, respectively. The detection limit for both compounds reached 5 ng/ml. No endogenous compound interfered in the assay. The linearity of the method and its within- and between-day precision were analytically satisfactory. 相似文献
4.
5.
《Physics and Chemistry of Liquids》2012,50(4):434-452
The absorption and fluorescence spectral characteristics of norepinephrine, epinephrine, isoprenaline, methyl dopa, orciprenaline and terbutaline have been investigated for levels of different pH and β-cyclodextrin (β-CD). The inclusion processes are discussed based on absorption, emission and semiempirical quantum mechanical calculations (CAChe – DFT). The pH study reveals that, deprotonation takes place in the CHOH group and the longer wavelength emission at 450?nm is due to intramolecular proton transfer. The β-CD study shows that the above-mentioned drugs form 1:1 inclusion complexes. Single-emission maximum in water (~316?nm) and dual emission (316?nm, 450?nm) in β-CD is noticed for drugs. In the β-CD solutions, the shorter wavelength fluorescence intensity is regularly decreased and longer wavelength fluorescence intensity is increased. The alkyl chain and the hydroxyl group are present in the interior and hydrophilic parts of the β-CD cavity, respectively. 相似文献
6.
在pH 9.3的氨-氯化铵缓冲溶液中,铽(Ⅲ)能与依诺沙星、十二烷基硫酸钠(SDS)形成荧光配合物(λex=330 nm、λem=545 nm),SDS的存在能增强配合物的荧光强度。研究发现,在该反应体系中加入适量雷公藤红素溶液后,铽(Ⅲ)与依诺沙星络合物的激发、发射峰位置不变,但其荧光强度呈规律性下降。据此,建立了简单、快速、灵敏地测定雷公藤红素的荧光分析方法。雷公藤红素的浓度在5.2×10-6~8.4×10-5 mol/L范围内呈良好线性关系,方法的检出限为4.1×10-8 mol/L。 相似文献
7.
提出了用同步荧光测定法同时测定盐酸普萘洛尔和盐酸氟桂利嗪。试验表明:荧光检测盐酸普萘洛尔的波长宜选定296nm、盐酸氟桂利嗪的波长宜选定263nm、波长差Δλ为50nm条件下进行同步扫描。盐酸普萘洛尔和盐酸氟桂利嗪的质量浓度分别在1.2×10-6~2.8×10-3g.L-1和2.0×10-5~3.6×10-3g.L-1范围内与荧光强度呈线性关系,检出限(3S/N)分别为3.2×10-7g.L-1和6.8×10-6g.L-1。方法用于混合样品中盐酸普萘洛尔与盐酸氟桂利嗪含量的同时测定,回收率在97.5%~101.1%和97.5%~101.7%之间。 相似文献
8.
Zhao Q Wang J Freeman JL Murphy-Jolly M Wright AM Scardino DJ Hammer NI Lawson CM Gray GM 《Inorganic chemistry》2011,50(5):2015-2027
Earlier studies of phosphine-substituted terthiophenes have demonstrated that some of these materials exhibit nonlinear absorption at 532 nm. However, this wavelength is significantly removed from the linear absorption maxima of the complexes, suggesting that better nonlinear absorption might be observed at wavelengths closer to the linear absorption maxima. To investigate this possibility, a library of compounds has been prepared either by varying the group attached to the nonbonding pair of electrons on the phosphorus atoms of 5,5'-bis(diphenylphosphino)-2,2':5',2'-terthiophene (PT(3)P), or by introducing additional substituents on the 5'-position of 5-(diphenylphosphino)-2,2':5',2'-terthiophene (PT(3)). All these compounds have been characterized using multinuclear NMR, UV-vis, and fluorescence spectroscopy. The compounds are strongly fluorescent, and both the fluorescence wavelength and the intensity depend upon the thiophene substituents. The nonlinear optical properties have also been evaluated at various wavelengths in the blue region. Each compound exhibits reverse saturable absorption, and the intensity of the reverse saturable absorption at a particular wavelength depends on the chemical structure of the compound. 相似文献
9.
Chen H Yu H Zhou Y Wang L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,67(3-4):683-686
A simple and sensitive fluorescent quenching method for the determination of trace hydrogen peroxide (H(2)O(2)) has been proposed to determine hydrogen peroxide in rain water sample. The method is based on the reaction of H(2)O(2) with 3,3'-diethyloxadicarbocyanine iodide (DI) to form a compound which has no fluorescence in acetate buffer solution (pH 3.09). The maximum emission wavelength of the system is located at 604 nm with excitation at 570 nm. Under the optimal conditions, the calibration graph was obtained between the quenched fluorescence intensity and hydrogen peroxide concentration in the range of 5.0 x 10(-7) to 9.0 x 10(-4) mol L(-1). The proposed method was applied to determine H(2)O(2) in rain water samples, and the result was satisfactory. The mechanism involved in the reaction was also studied. 相似文献
10.
Hadjmohamadi MR Chaichi MJ Biparva P Alizadeh K 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(2):358-361
Effect of aliphatic amines and their concentration on fluorescence intensity of 4-methyl umbelliferone (4-MU) one of coumarin derivative were investigated. This compound has blue light emission under UV lamp in methanolic solution. Spectral investigation of 4-MU solution containing amine compounds showed lower intensity at 350-410 nm (quenching region) and higher intensity at 430-500 nm (enhancing region) as compared to pure methanolic solution of 4-MU. Fluorescence intensity at isoemitting point was independent from concentration of amines. The variation of fluorescence intensity could be used for determination of aliphatic amines in both quenching and enhancing region. Linear ranges for determination of amines in the quenching region were obtained from Stern-Volmer diagram of 4-MU. Determination of amines at fluorescence enhancing region using inverse fluorescence intensity against inverse amine concentration (bireciprocal plot) were investigated and related equations was also proposed. 相似文献
11.
Qin S 《Annali di chimica》2007,97(1-2):59-67
Hemoglobin (Hb) could be used as a substitute of peroxidase in the catalytic oxidation of tetra-substituted amino aluminum phthalocyanine (TAA1Pc) by H2O2. We found that the fluorescence of TAA1Pc (a red-region fluorescent dye with a maximum excitation wavelength at 606 nm and a maximum emission wavelength at 673 nm) could significantly be quenched by H2O2 in the presence of Hb. The value of F0/F (where the relative fluorescence intensity of blank solution and that of the sample solution containing Hb were given by F0 and F, respectively) is linearly related to the concentration of Hb. Based on this, a novel fluorimetric method was developed for the determination of Hb in aqueous solution. Under optimal conditions, Hb could be determined in the concentration range of 5 x 10(-11) - 12 x 10(-8) mol L(-1) with a detection limit of 1.5 x10(-11) mol L(-1). The relative standard deviation of ten replicate measurements was 1.95% for solution containing 1 x10(-9 ) mol L(-1) Hb. The proposed method has been applied to the analysis of Hb in human blood and the results were in good agreement with those reported by a hospital laboratory. So this is a new, high sensitive and precise fluorescence quenching method to determine Hb. 相似文献
12.
Zhao HC Ding F Wang X Ju H Li A Jin LP 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(2):332-336
Fluorescence of terbium(III) is sensitized when excited in the presence of ciprofloxacin (CPLX) in the aqueous solution because a Tb(III)-CPLX complex is formed and the maximum fluorescence peak locates at 545 nm. The second-order scattering (SOS) peak at 545 nm also appears for the Tb(III)-CPLX complexes with the excitation wavelength of 272 nm. The intensity at 545 nm obviously increases when the silver nanoparticles are added to the Tb(III)-CPLX system, and the relative intensity is proportional to the concentration of CPLX. Based on this phenomenon, a new method for the determination of CPLX has been developed by using a common spectrofluorometer to measure the intensity of fluorescence and SOS. The intensity is enhanced most by silver nanoparticles at pH 6.0. The calibration graph for CPLX is linear in the range of 3.0 x 10(-9) to 1.0 x 10(-5) mol l(-1). The detection limit is 8.5 x 10(-10) mol l(-1). The method was applied satisfactorily to the determination of CPLX in tablets and capsules. The results show that silver nanoparticles with certain size and concentration can enhance the fluorescence and SOS intensity of the system. 相似文献
13.
Determination of ranitidine, nizatidine, and cimetidine by a sensitive fluorescent probe 总被引:1,自引:0,他引:1
A validated, simple, and sensitive fluorescence quenching method for the determination of ranitidine, nizatidine, and cimetidine in tablets and biological fluids is presented. This is the first single fluorescence method reported for the analysis of all three H(2) antagonists. The competitive reaction between the investigated drug and the palmatine probe for the occupancy of the cucurbit[7]uril (CB[7]) cavity was studied using spectrofluorometry. CB[7] was found to react with the probe to form a stable complex. The fluorescence intensity of the complex was also enhanced greatly. However, the addition of the drug dramatically quenched the fluorescence intensity of the complex. Accordingly, a new fluorescence quenching method for the determination of the studied drugs was established. The different experimental parameters affecting the fluorescence quenching intensity were studied carefully. At optimum reaction conditions, the rectilinear calibration graphs between the fluorescence quenching values (ΔF) and the medicament concentration were obtained in the concentration range of 0.04-1.9 μg mL(-1) for the investigated drugs. The limits of detection ranged from 0.013 to 0.030 μg mL(-1) at 495 nm using an excitation wavelength of 343 nm. The proposed method can be used for the determination of the three H(2) antagonists in raw materials, dosage forms and biological fluids. 相似文献
14.
利用荧光光谱研究了脱落酸(Abscisic acid)与伊文思蓝(Evans blue)的相互作用。用266 nm激发光激发时,伊文思蓝的最大发射波长为396 nm。伊文思蓝与脱落酸相互作用,使伊文思蓝发生荧光猝灭,根据Stern-Volmer方程研究了荧光猝灭的类型及机理,实验证明脱落酸与伊文思蓝发生的静态猝灭,即脱落酸和伊文思蓝形成了一种稳定的复合物。伊文思蓝的相对荧光强度与脱落酸的浓度线性相关,线性方程为F0/F=0.78153+3.9153×104c,线性相关系数为0.9976。通过实验求算了脱落酸与伊文思蓝的结合点常数KABA-EB=1.838×105L/mol和结合点数n=1.171,由此建立了测定植物中脱落酸的新方法。 相似文献
15.
新型近红外试剂的合成及其现场二聚体与DNA作用的研究 总被引:6,自引:0,他引:6
合成了一种新型近红外阴离子染料,并对其水溶液及阳离子表面活性剂CTAB存在下的吸收荧光光谱进行了研究。结果表明,低浓度的CTAB与该近红外阴离子染料形成离子缔合物而使阴离子染料的荧光强度降低,当CTAB的浓度进一步加大时,其胶束前预聚集促使该染料形成非荧光二聚体,导致荧光急剧猝灭。 相似文献
16.
The aim of the present work was to develop a new method using synchronous fluorescence spectrometry (SFS) to determine the concentration of isoliquiritigenin (ISL) in mouse blood and tissues, and to investigate ISL's distribution among organs after an intraperitoneal (IP) dose of ISL. The synchronous fluorescence method was optimized with the sample pH, stability, metal ions, concentration of Al(3+), and surfactants. The proposed method was used to determine the ISL concentration in mouse blood, brain, heart, kidney, liver, spleen and lung after an IP injection of ISL. The optimal conditions for the determination of ISL using SFS were found to be: excitation and emission wavelengths of 469 and 557 nm, respectively; the use of 3% AlCl(3) as a fluorescence intensity enhancer; measuring samples within 1 h of collection, sample pH 7-8, isolation of samples from surfactants; and wavelength interval (Δλ) = 70 nm. After IP injection, the distribution of ISL in mouse organs was: liver > kidney > spleen > blood > lung > brain > heart. The blood concentration of ISL peaked at 60 min; concentrations of ISL in liver, kidney and spleen achieved maxima at 120 min. SFS provides a simple, but effective analytical method that will benefit the study of in vivo biological effects of ISL, including absorption, distribution, metabolism, and excretion. 相似文献
17.
13-Hydroxyacenaphtho[1,2-b]quinolizinium bromide (13-HQBr)was selected as a fluorescence indicator to determine basic compounds in non-aqueous media. This compound possesses an acidic phenolic hydroxyl group. It presents varying absorption (ROH, 408, 430 nm; RO(-) 456, 478 nm) and excitation spectra (ROH, 425 nm; RO, 471 nm) depending on the pH of the media, but the same emission fluorescence spectrum (ROH = RO(-), 526 nm) at different pH in buffered aqueous solutions. However, in acidic non-aqueous media (acetic, formic and trifluoroacetic acids), it can be observed that the fluorescence emission spectra differ for the ionized (lambda(em) = 530 nm) and non-ionized (lambda(em) = 440, 470 nm) forms. The fluorescence intensity at the characteristic peaks depends on the acid-base equilibria in the ground and excited states. Therefore, this property could be used to evaluate the concentration of basic compounds, showing a good linearity range between fluorescence intensity and basic sample concentration. 相似文献
18.
构建了一种新型免标记的双发射荧光比率核酸探针(GelRed/[G40]/Tb^3+)并用于Ag+的检测。对于GelRed/[G40]/Tb^3+探针,GelRed作为一种核酸染料嵌入到单链DNA-[G40]中,形成的GelRed/[G40]作为稳定的内置参照标准,在激发波长290 nm处,发射荧光强度固定不变的红色荧光(发射波长为635 nm),而[G40]/Tb^3+作为敏感的响应信号,随着Ag^+浓度的增加,产生的绿色荧光逐渐增强(发射波长为545 nm),[G40]/Tb3+与GelRed/[G40]发射的荧光强度比值也发生相应的改变,从而实现对Ag^+的定量检测。在优化的实验条件下,[G40]/Tb^3+与GelRed/[G40]荧光强度比值和Ag^+浓度在0~7.5μmol/L的范围内具有较好的线性关系,Ag^+检出限为0.156μmol/L。本传感器在10 min内就可完成对Ag^+的分析。方法已用于自来水样中Ag^+的检测,与ICP-MS法检测结果一致。 相似文献
19.
A highly sensitive fluorescence-quenching method for the determination of phosphorus based on the formation of an ion associate between molybdophosphate and Rhodamine B (RB) was developed. A simple flow-injection system coupled with a fluorescence detector was used to measure the fluorescence intensity at 560 nm and 580 nm as an excitation and an emission wavelength, respectively. The calibration graph for phosphorus showed a good linearity in the range of (0 - 1) x 10(-7) M (1 M = 1 mol L(-1)), and a detection limit of 1 x 10(-9) M (S/N = 3). The proposed method was successfully applied to the determination of ultratrace amounts of phosphorus in ultrapurified and purified water samples, and to the determination of trace amounts of phosphorus in commercially-available hydrogen peroxide solutions with satisfactory results. 相似文献
20.
通过双Suzuki偶联反应一步合成了2种含硫甲基的芴-苯结构化合物2,7-二(4-硫甲基苯基)-9,9-二己基-芴(a)和2,7-二(2,6-二甲基-4-硫甲基苯基)-9,9-二己基-芴(b).紫外-可见和荧光光谱以及分子轨道理论计算表明,位阻较小的化合物a具有更好的共轭性能,其最大紫外-可见吸收波长达到351nm,比两端苯基含4个邻位取代基的化合物b红移了38nm;化合物a的最大荧光发射波长达到410nm,为典型的蓝光化合物,比化合物b红移了43nm.化合物a和b都具有较高的荧光量子产率,分别为59%和65%,在光电材料方面具有潜在的应用前景. 相似文献