Terbium determination

FLUORIMETRIC DETERMINATION OE KETOROLAC AND KETOPROEEN IN DOSAGE EORMS USING TERBIUM SENSITIZED LUMINESCENCE... 

THE DETERMINATION OF COPPER MICROAMOUNTS ON THE TERBIUM LUMINESCENCE SENSITIZED BY IT IN HETEROBINUCLEAR COMPLEX... 

Time-resolved approaches for multi-analyte immunoassays have been described recently. Simultaneous determination of LH, follicle stimulating hormone (FSH), hCG, and prolactin (PRL) in a multisite manual strip format has been reported. 88 Four microtiter wells are attached to a plastic strip, two-by-two and back-to-back, such that the wells can be read on a microtiter plate reader. In a quadruple-label format, the simultaneous quantitative determination of four analytes in dried blood spots can be done using europium, samarium, dysprosium, and terbium. 89 In this approach, thyroid-stimulating hormone, 17-a-hydroxyprogesterone, immunoreactive trypsin, and creatine kinase MM (CK-MM) isoenzyme are determined from dried blood samples spotted on filter paper in a microtiter well coated with a mixture of antibodies. Dissociative fluorescence enhancement of the four ions using cofluorescence-based enhancement solutions enables the time-resolved fluorescence of each ion to be measured through four narrow-band interference filters. 

I. A. Hemmila, Time-resolved fluorometric determination of terbium in aqueous solution, Anal. Chem. 57, 1676-1681 (1985). 

R. W. Wallace, E. A. Tallant, M. E. Dockter, and W. Y. Cheung, Calcium binding domains of calmodulin. Sequence of fill as determined by terbium luminescence, J. Biol. Chem. 257, 1845-1854 (1982). 

The element was discovered in 1843 by Carl Gustav Mosander. He determined that the oxide, known as yttria, was actually a mixture of at least three rare earths which he named as yttria—a colorless oxide, erbia— a yellow oxide, and terbia— a rose-colored earth. Mosander separated these three oxides by fractional precipitation with ammonium hydroxide. Pure terbia was prepared by Urbain in 1905. The element was named terbium for its oxide, terbia, which was named after the Swedish town, Ytterby. 

An alternate explanation of the emission intensities of terbium in the presence of other ions was given by Peterson and Bridenbaugh (54), that for europium was given by Axe and Weller (52). These authors point out that resonance exchange is a major factor in determining the emission intensities in these cases. This work has shed some doubt on the necessity of phonon-assisted transfer for the terbium and europium ions in the cases considered by Van Uitert and Iida. 

The rates of internal conversion from the 5Z)3 to the 5D4 states were also measured. The backup oxide in this case was yttrium. This information was obtained by determining the rise time of the 5Z)4-state green fluorescence as a function of time, when the 5Z>3 state was excited. The rise time of the 5Z)4 state is, of course, the decay time of the 5Z>3 state. It was assumed that the decay of the 5Z)3 was predominantly due to an efficient internal conversion process to the 5D4. Measurements of the decay time of the 5Z)3 state directly were not possible, since the emission from this state is very weak if not, indeed, absent. The result of this study is shown in Fig. 23, where it can be seen that the internal-conversion time remains constant at about 17 fxsec up to a terbium oxide concentration of 1 mole per cent. At higher concentrations, the internal conversion time falls rapidly, until at 10 mole per cent terbium oxide the value is about 1.7 /xsec. This is down by a factor of 10 over samples containing 1 mole per cent or less of terbium oxide. 

In another study, Kondrat eva (103) made a determination of the luminescent quantum yield of the 5D4 state of the terbium ion in aqueous solution. The method used was based upon fluorescent-lifetime measurements and had previously been used by Rinck (96) and Geisler and Hellwege (96) to determine the quantum yield of rare earths in crystals. Kondrat eva made his studies on chloride and sulfate solutions, using the electronic shutter technique of Steinhaus et al. (66). 

Kleinerman and co-workers (158) reported an enhancement of fluorescent yield of chelated lanthanide ions by Lewis bases. They observed that in liquid, plastic, and glassy solutions containing terbium europium, and samarium chelates, the use of Lewis bases accomplishes the same effect as substituting deuterium for hydrogen. Not all bases, however, are equally effective. The molecular size of the base does not appear to be particularly important, since strong enhancement effects can be obtained with both bulky and small molecules. The nature of the atom of the base having the unshared electron pair is not a determining factor in the enhancement phenomenon. 

M. A. Fotopoulou and P. C. Ioannou, Post-Column Terbium Complexation and Sensitized Fluorescence for the Determination of Norepinephrine, Epinephrine and Dopamine Using High-Performance Liquid Chromatography, Anal. Chim. Acta 2002,462, 179. 

The determination of terbium is discussed under Multi-Metal Analysis of Soils in Sects. 2.55 (emission spectrometry) and 2.55 (neutron activation analysis). 

Metal complexes like lanthanide chelates (mainly europium or terbium), ruthenium phenanthrolines or bipyridyls, and platinum porphyrins can be used as fluorescent labels for biomolecules. Their long decay times are perfectly suited for a detection by time-resolved imaging, and the labeled target molecules can be used for the determination of intracellular recognition processes or for the screening of DNA and protein arrays. Ratiometric lifetime-based imaging methods in combination with sophisticated data acquisition and evaluation tools can substantially contribute to the development... 

Bacigalupo, M.A., G. Meroni, and R. Longhi. 2006. Determination of carbofuran in water by homogeneous immunoassay using selectively conjugate mastoparan and terbium/dipicolinic acid fluorescent complex. Talanta 69 1106-1111. 

Ioannou et al. [41] reported the use of terbium sensitized fluorescence to develop a sensitive and simple fluorimetric method for the determination of the anthranilic acid derivative, mefenamic acid. The method makes use of radiative energy transfer from anthranilate to Tb(III) in alkaline methanolic solutions. Optimum conditions for the formation of the anthranilate-Tb(III) complex were investigated. Under optimized conditions, the detection limit was 1.4 x 10-8 mol/L, and the range of application was 2.5 x 10 8 to 5.0 x 10 5 mol/L. The method was successfully applied to the determination of mefenamic acid in serum after extraction of the sample with ethyl acetate, evaporation of the organic layer under a stream of nitrogen at 40°C, and reconstitution of the residue with alkaline methanolic terbium solution prior to instrumental measurement. The mean recovery from serum samples spiked with mefenamic acid (3.0 x 10-6, 9.0 x 10-6, 3.0 x 10-5 mol/L) was 101 5%. The within-run precision (RSD) for the method for the two serum samples varied from 2 to 8%, and the day-to-day precision for two concentration levels varied from 2 to 13%. 

Chauvin, A.-S., Gumy, F., Imbert, D., and BunzU, J.-C.G (2004) Europium and terbium tris(dipicolinates) as secondary standards for quantum yield determination. Spectroscopy Letters, 37 (5), 517-532. 

Early in 1999, the properties of a series of terbium complexes based on l-phenyl-3-methyl-4-R-5-pyrazolone were analyzed to determine how both the central ligand and the neutral ligand significantly affect the PL and EL quanmm efficiency [63]. Of the materials listed in Figure 11.22, PMIP-Tb-TPPO shows the highest EL efficiency and luminance, corresponding to its high PL efficiency. 

The complex of A-(2-pyridinyl)-3-ketobutyramide with Tb + in methanol solution can emit the intrinsic fluorescence of Tb +. When EtsN and Zn + are added to the solution, the fluorescence (kex = 329 nm, ka = 546 nm) is significantly enhanced. This sensitive fluorescence enhancement system can be used for the determination of terbium ion ". ... 

Some lanthanide /3-diketonate complexes (11, M = Pr, Eu, Dy, R = n-Pr, R = f-Bu) have selectivity for further coordination with Cl ions, over F , Br , I , C104, SCN , OH, AcO , HCOs, N03 and SOa ", and are the active component of ion-selective electrodes (ISE) for CG. It was proposed to take advantage of the luminescence in the visible range associated with CH complexation, for the development of specific naked eye optodes (M = Eu) for this ion . A sensitive fiuorescence enhancement system for the determination of terbium was developed and studied. This method was applied to... 

Contrary to the previous case, parvalbumin binds only two Ca ions. Compared to the technical difficulties encountered at the K-absorption edge of calcium due to increased absorption of 3 A wavelengths, the quantitative replacement of Ca by terbium ions (Lj-edge at 1.648 A) offers an ideal way to obtain structural information about the ion binding sites of parvalbumin by resonance scattering experiments. In fact, Miake-Lye, Doniach and Hodgson were able to determine for the first time the distance between the center of mass of the parvalbumin and its two terbium ion binding sites in solution. 

The aqueous colloidal solutions of activated lanthanide orthophosphate nanocrystals stable for more than 3 months have been prepared and optimal activator concentration for such systems has been determined. It is 15 mol.% of terbium in CeP04 Tb, 20 mol.% of europium for LaP04 .Eu and 35 mol.% of cerium for LaP04 Ce. Non-toxicity within the limits of working concentrations allows such colloidal solutions to be proposed as new multifunctional luminophores for biological applications. 

Brunfelt, A. O., Steinnes, E. Determination of lutetium, ytterbium and terbium in rocks by neutron activation and mixed solvent anion-exchange chromatography. Analyst 94, 979 (1969)... 

Only one isotope of terbium occurs in nature terbium-159. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element s name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. 

Fotopoulou, M. A. Ioannou, P. C., Post-column terbium complexation and sensitized fluorescence detection for the determination of norepinephrine, epinephrine and dopamine using high-performance liquid chromatography, Anal. Chim. Acta 2002, 462, 179-185... 

---