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1.
The sensitized luminescence of europium ion in complexes with thiaprophenic acid has been investigated. It is shown that the luminescence intensity of the Eu (III) increases by 107 times as the result of intramolecular energy transfer from ligand to lanthanide ion. The luminescence properties of the complex have been studied in solutions and a highly sensitive luminescence method for the determination of thiaprophenic acid has been developed. 相似文献
2.
This paper explores an ultra-sensitive luminescence method for the determination of Ketoprofen (KP) in pharmaceutical formulations.
The technique is indirect and exploits the luminescence enhancement of terbium (Tb3+) by complexation with KP (Tb3+–KP), which was monitored at respective excitation and emission wavelengths of λ
ex = 258 nm and λ
em = 549 nm. The effect of varying the Tb3+ concentration and using multiple solvents was examined to determine optimal experimental conditions. Maximum sensitization
was accomplished in the presence of methanol where the most favourable condition for the formation of the complex was recorded
at a level of 1.0 × 10−5 M of Tb3+. Under these optimum experimental conditions, linear calibration curve was obtained in the range of 2.8 × 10−7–3.1 × 10−6 M with a detection limit of 8.7 × 10−8 M. The technique was validated with ‘working’ reference standards and produced relative standard deviations < 2% indicating
that the reproducibility was highly acceptable. The proposed method was successfully applied to assays of KP in pharmaceutical
formulations with average recoveries of 92–98%. The results were found to be in good agreement with those obtained by HPLC.
The method is highly suited for general applications of this nature. 相似文献
3.
The method for the direct determination of norfloxacin, without prior separation, in serum and pharmaceutical formulations, by means of fluorometry and second derivative u.v. spectrophotometry, was developed. Fluorometric assay of norfloxacin in serum was carried in 0.1 M HCl, with the adition of sodium-dodecylsulphate, at emission wavelength 450 nm (excitation 320 nm). Linear calibration curve was obtained in the concentration range 20 – 320 μg/L with the detection limit 2μg/L. The second derivative spectrophotometry was used for the determination of the norfloxacin in tablets at 337 nm using 0.05 M NaOH as solvent. Detection limit was 30μg/L. 相似文献
4.
采用高温固相反应合成了NaZnLa(PO4)2中掺杂Ce3+、Tb3+的荧光体,对其晶体结构、发光行为进行了研究,并尝试对NaZnLa(PO4)2:Ce,Tb荧光体进行调制。NaZnLa(PO4)2是LaPO4的同构物,为单斜晶系独居石结构,从XRD谱数据得到NaZnLa(PO4)2基质的晶胞参数为a=0.6823nm,b=0.7045nm,c=0.6497nm,β=1039°,v=0.303nm3,其晶胞参数与单斜LaPO4的晶胞参数相似。在NaZnLa(PO4)2:Ce,Tb荧光体中,Ce3+对Tb3+有良好的敏化作用,掺杂适量的BO33-、Al3+、Dy3+,可以增强发光亮度。 相似文献
5.
S. V. Bel''tyukova E. I. Tselik A. V. Egorova N. P. Efryushina 《Journal of Applied Spectroscopy》2001,68(4):598-601
The possibility of obtaining new luminescent materials based on the CaA zeolite modified by complex compounds of Eu(Tb) with diphenacylphosphinic acid has been shown. The optimal sorption conditions have been established and the luminescent characteristics of the sorbates have been determined. 相似文献
6.
7.
采用高温固相反应合成了NaZnLa(PO4 ) 2 中掺杂Ce3 +、Tb3+的荧光体 ,对其晶体结构、发光行为进行了研究 ,并尝试对NaZnLa(PO4 ) 2 ∶Ce ,Tb荧光体进行调制。NaZnLa(PO4 ) 2 是LaPO4 的同构物 ,为单斜晶系独居石结构 ,从XRD谱数据得到NaZnLa(PO4 ) 2 基质的晶胞参数为a =0 6 82 3nm ,b =0 70 45nm ,c =0 6 497nm ,β =10 3 9° ,V =0 30 3nm3,其晶胞参数与单斜LaPO4 的晶胞参数相似。在NaZnLa(PO4 ) 2 ∶Ce ,Tb荧光体中 ,Ce3 +对Tb3+有良好的敏化作用 ,掺杂适量的BO3 -3 、Al3 +、Dy3 +,可以增强发光亮度 相似文献
8.
The fluorescence system of the norfloxacin-Tb3+- sodium dodecylbenzene sulfonate (SDBS) was investigated in this paper. The experiments indicated that the fluorescence intensity
of the Tb3+-SDBS was greatly enhanced by the norfloxacin. On the basis of the above findings, a sensitive fluorimetric method for determining
the norfloxacin was established. The fluorescence intensity was measured by a 1-cm quartz cell with the excitation wavelength
of 290 nm and the emission wavelength of 545 nm. The enhanced fluorescence intensity of the system (Δ F) showed a good linear
relationship with the concentration of norfloxacin in the range of 5.0×10−9 mol L−1–2.0×10−6 mol L−1, its correlation coefficient was 0.9991 and the detection limit (S/N=3) was 1.2×10−9 mol L−1. The presented method was used to determine the norfloxacin in real pharmaceutical samples. The luminescence mechanism was
also discussed in detail. In the fluorescence system of the norfloxacin-Tb3+-SDBS, the SDBS not only acted as the surfactant, but also acted as the energy donor. 相似文献
9.
采用高温熔融法分别制备了高含量Tb~(3+)单掺和Dy~(3+)/Tb~(3+)共掺的镓硼锗硅酸盐(GBSG)发光玻璃,并分析了其光谱性能。根据Dy~(3+)和Tb~(3+)掺杂的镓硼锗硅酸盐(GBSG)玻璃的激发和发射光谱、荧光寿命衰减曲线等特性,探讨了Dy~(3+)与Tb~(3+)之间的能量传递关系。结果表明:玻璃的发光强度和荧光寿命随着Tb~(3+)、Dy~(3+)含量的增加而减少。与相同摩尔浓度的单掺玻璃相比,共掺玻璃发光强度的衰减速率先减慢而后加快。Tb~(3+)、Dy~(3+)离子之间的能量传递方式为无辐射共振能量传递和~4F_(9/2)+~7F_6→~6H_(15/2)+~5D_4交叉弛豫效应。 相似文献
10.
11.
We have measured the relative luminescence quantum yields and luminescence lifetimes of Tb(III) and Dy(III) ions in complexes
with pyrazole-5-carboxylic acids. Based on study of the time-resolved luminescence spectra of Tb(III) and Dy(III) complexes
with 3-(6-benzodioxanyl)pyrazole-5-carboxylic acid, we have demonstrated the possibility in principle of determining Dy(III)
in the presence of Tb(III) by separating the short-lived component of the luminescence of dysprosium, despite the practically
complete overlap of the analytical bands of dysprosium by the terbium bands. This method was used to determine Dy(III) in
luminescent materials: scandium borates doped with terbium and dysprosium.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 3, pp. 327–331, May–June, 2007. 相似文献
12.
S. V. Bel'tyukova E. I. Tselik A. V. Egorova O. I. Teslyuk 《Journal of Applied Spectroscopy》2003,70(2):307-310
The luminescence of the sorbates of the Eu(III) and Tb(III) complexes on the CaA-type zeolite with derivatives of aliphatic and aromatic carbonic acids has been studied. It is shown that the luminescent materials obtained can be used as light regulators and transformers which absorb energy in the UV spectral region and transform it into visible radiation. 相似文献
13.
14.
Jun-Gill Kang Tack-Jin Kim Hee-Jung Kang Younbong Park Min-Koo Nah 《Journal of luminescence》2008,128(12):1867-1872
Two novel complexes of Sm(III) and Dy(III) with mixed oxydiacetate (ODA) and 1,10-phenanthroline (phen) ligands were synthesized and their structure and luminescence properties were characterized. The complexes of [Ln(ODA)(phen)·4H2O]Cl·5H2O [Ln=Sm and Dy] crystallize in the monoclinic space group P21/n with Sm: a=12.3401(14) Å, b=16.821(2), c=12.6847(11) Å, β=107.939(10)°, V=2505.0(5) Å3, Z=4 and ρ=1.841 mg/m3, and with Dy: a=12.289(7) Å, b=16.805(6) Å, c=12.705(4) Å, β=108.144(18)°, V=2493.4(19) Å3, Z=4 and ρ=1.786 mg/m3. The complexes of [Sm(ODA)(phen)·4H2O]+ and [Dy(ODA)(phen)·4H2O]+ excited by UV light produce orange red and lightly white emissions, respectively, via the nonradiative energy transfer from phen to the metals. The quantum yield of the sensitized luminescence of [Dy(ODA)(phen)·4H2O]+ (Q=19%) is much greater than that of [Sm(ODA)(phen)·4H2O]+ (Q=1.4%). The luminescence decay times of the complexes were in a few microsecond range and independent of temperature. 相似文献
15.
N. V. Gaponenko I. S. Molchan S. V. Gaponenko A. V. Mudryi A. A. Lyutich J. Misiewicz R. Kudrawiec 《Journal of Applied Spectroscopy》2003,70(1):59-64
We have investigated the luminescence, luminescence excitation, and transmittance of europium- and terbium-doped xerogel films formed on smooth, nanotextured surfaces and in the pores of anodic aluminum oxide. Some factors responsible for enhancement of luminescence in the structure lanthanide-doped xerogel/mesoporous anodic aluminum oxide have been analyzed. It is assumed that the optical excitation of lanthanide ions can be realized directly, through a xerogel matrix, and due to the multiple scattering of exciting radiation by the matrix of mesoporous anodic aluminum oxide. 相似文献
16.
A novel light conversion agent (NLCA) has been synthesized that is applicable to polyethylene (PE) film. The composition and structure of the NLCA was characterized by elemental analysis, Fourier transform infrared (FT‐IR) spectroscopy, and nuclear magnetic resonance (NMR) spectrometry. The morphology, particulate dimensions, dispersion property and compatibility of the NLCA were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results indicate that the average particulate dimension was about 60–100 nm and they were dispersed well in the PE film. The luminescence property of the NLCA was studied via fluorescent spectrometry. The fluorescence spectra of the NLCA show that the NLCA has a highly efficient luminescence. 相似文献
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19.
In a suitable pH buffer solutions, sodium diethyldithiocarbamate (DDTC) reacts with some divalence metal ions M(II) to form
(M–DDTC)
n
chelate complex nanoparticles, which exhibit different luminescence properties. There is a strongest luminescence peak at
470 nm for the Co(II)–DDTC system, three peaks at 330, 470, and 630 nm for the Cu(II)–DDTC system, three peaks at 420, 470,
and 630 nm for the Cd(II)–DDTC system, four peaks at 350, 400, 435, and 470 nm for the Ni(II)–DDTC system, two peaks at 408
and 470 nm for the Pb(II)–DDTC system, two peaks at 415 and 470 nm for the Fe(II)–DDTC system. The different luminescence
properties of (M–DDTC)
n
chelate complex nanoparticles was explained. Under the optimal conditions, the luminescence intensity of (Co–DDTC)
n
chelate complex nanoparticles at 470 nm (F
470 nm) is linear to Co(II) concentration in the range of 0.012–1.44 μg/mL. The detection limit is 0.0023 μg/mL. A novel luminescence method has been proposed for the determination of cobalt in Vitamin B12 samples, with satisfactory results. 相似文献
20.
Yu. V. Korovin N. V. Rusakova Yu. A. Popkov V. P. Dotsenko 《Journal of Applied Spectroscopy》2002,69(6):841-844
We have studied the spectral-luminescent characteristics of ytterbium and neodymium ions in complexes with new polydentate bis-crown-ether and bis-azacyclic ligands both of whose parts are bound by 2,9-substituted 1,10-phenanthroline. The relationship between the intensity, rare-earth ion luminescence lifetime, and the composition of the coordination sphere of the complexes is established. Using the considered compounds as an example, we show the advantage of the joint influence of screening of the central ion from the effect of high-frequency O–H- and C–H vibrations of the solvent molecules and of the photoantenna effect in improvement of the luminescent characteristics of lanthanides. 相似文献