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Stefan Lis Bronisław Marciniak Marian Elbanowski 《Monatshefte für Chemie / Chemical Monthly》1989,120(10):821-826
Summary The Tb(III)-acetylacetone system in ethanol solution has been studied by spectroscopic methods. The formation of a Tb(III)/acetylacetone (1:1) complex in the ground state has been proved and its stability constant determined,K=(0.97±0.06)·104dm3mol–1. The role of this complex in the spectrofluorimetric determination ofLn(III) ions in the presence of acetylacetone has been discussed.
Über die Rolle eines Tb(III)-Acetylaceton-Komplexes im Grundzustand in der sensibilisierten Emission von Tb(III) in Ethanol-Lösung
Zusammenfassung Das Tb(III)-Acetylaceton-System in Ethanol-Lösung wurde mit spektroskopischen Methoden untersuchung. Die Bildung eines Tb(III)-Acetylaceton(1:1)-Komplexes im Grundzustand wurde bestätigt und seine Stabilitätskonstante bestimmt,K=(0.97±0.06)·104dm3mol–1. Die Rolle dieses Komplexes in der spektrofluorimetrischen Bestimmung vonLn(III)-Ionen in Gegenwart von Acetylaceton wurde erörtert.相似文献
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J.M. Cano Pavón A. Garcia de Torres M.E. Ureña Pozo F. Sanchez Rojas E. Cristofol Alcaraz 《Analytica chimica acta》1989
A spectrofluorimetric method, based on the formation of a fluorescent complex with salicyladehyde carbohydrazone, is optimized for the determination of thorium (20–800 μg l?1) at “pH” 1.3–1.7. The relative standard deviation is 2.7% for 100 μg Th l?1. The method is applied to synthetic mixtures containing various amounts of thorium and to the determination of thorium in monazite samples. 相似文献
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Potassium oxalate acts as a specific reagent in enhancing the fluorescence intensity of terbium in aqueous solutions. Maximum fluorescence intensity is obtained by irradiating (at 255 mμ) terbium(III) dissolved in 0.01 M potassium oxalate solution at pH 7.8. The enhancement and quenching phenomena caused by other lanthanides, errors in the determination, and various examples of spectrofluorimetric analysis of traces of terbium in mixtures with other lanthanides are described. The sensitivity of the method is 5·10-2μg/ml of terbium. 相似文献
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Lei Wang 《Analytical sciences》2004,20(8):1237-1239
A new luminescence-enhancement system based on complex formation between europium and sparfloxacin in the presence of lutetium in a sodium dodecyl sulfate solution has been discovered. By adding a suitable amount of Lu3+ to the Eu-sparfloxacin-sodium dodecyl sulfate system, the luminescence can be enhanced by approximately 5-fold compared with that of the system without Lu3+. Under the optimum conditions, the luminescence intensity of the system is a linear function of the concentration of europium in the range of 1.0 x 10(-10) - 5.0 x 10(-7) mol L(-1). The detection limit of europium is 2.0 x 10(-13) mol L(-1) (S/N = 3). The system was used for the determination of trace amounts of europium in rare earth samples with satisfactory results. 相似文献
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Spectrophotometric determination of trace amounts of acetylacetone in aqueous solutions 总被引:1,自引:0,他引:1
A sensitive spectrophotometric method for the determination of trace amounts of acetylacetone in aqueous solution is carried out. In the presence of bicarbonate solution, diazotized anthranilic acid reagent reacts rapidly with acetylacetone to form a yellow-colored compound with maximum absorption at 330 nm, which is water-soluble and reasonably stable. Adherence to Beer's law is observed in the range 20–200 μg of acetylacetone/25 ml, with a molar absorptivity of 19.5 × 103 liters mol−1 cm−1, a sensitivity index of 0.0051 μg cm−2, relative to + 0.3 to −0.9%, and a relative standard deviation of 0.5–1.4%, depending on the concentration level. 相似文献
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The fluorescent reagent 5-bromo-salicylaldehyde salicyloylhydrazone (5-Br-SASH) was synthesized and its ionization constants were established spectrophotometrically. The fluorescent reaction of this reagent with aluminium was studied. Based on this chelation reaction, a spectrofluorimetric method was developed for the determination of aluminium in acetic acid-ammonium acetate buffer solution of pH 5.4. Under these conditions, the A1-5-Br-SASH complex has excitation and emission maxima at 370 and 460 nm, respectively. The linear range of the method is from 0 to 120 ppb and the detection limit is 1.1 ppb of aluminium. The molar ratio of aluminium to the reagent is 1:3. Interferences of other ions were studied. The method was successfully applied to the determination of aluminium in glucose injection and common beverages. 相似文献
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Wei W Wang H Jiang C 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(2):241-246
A new spectrofluorimetric method was developed for determination of trace amount of heparin (Hep). Using lomefloxacin (LOM)-terbium ion (Tb3+) as a fluorescent probe, in the buffer solution of pH 8.70, Hep can remarkably enhance the fluorescence intensity of the LOM-Tb3+ complex at lambda = 545 nm and the enhanced fluorescence intensity of Tb3+ ion is in proportion to the concentration of Hep. Optimum conditions for the determination of Hep were also investigated. The linear range for the determination of Hep was 0.6-2.0 microg/ml and the detection limit was 45.22 ng/ml. This method is simple, practical and relatively free of interference from coexisting substances and can be successfully applied to assess Hep in biological samples. By the Rosenthanl graphic method, the association constant of Hep with the probe is 4.56 x 10(4) l/mol and binding numbers is 18.2. Moreover, the enhancement mechanism of the fluorescence intensity in the LOM-Tb3+ system and the LOM-Tb3+-Hep system have also been discussed. 相似文献
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The ion-association complex formed between a thiocyanato-iron(III) ion and a benzyltriethylammonium ion is extracted into 1,2-dichloroethane, and its absorbance at 476 nm is used for determination of the iron. Beer's law is obeyed up to about 4 mug/ml iron concentration in the final solution. The molar absorptivity is 2.79 x 10(4) l.mole(-1).cm(-1). 相似文献
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Rapid and sensitive spectrophotometric determination of trace amounts of iron(III) using leuco Xylene cyanol FF 总被引:1,自引:0,他引:1
A new, simple, sensitive, and reliable method is presented for the rapid spectrophotometric determination of trace amounts of iron(III) using leuco Xylene cyanol FF. The method is based on the oxidation of leuco Xylene cyanol FF (LXCFF) to its blue form of xylene cyanol FF by iron(III) in sulfuric acid medium (pH 2.0–3.0), the absorbance of the formed dye is measured in an acetate buffer medium (pH 2.8–4.4) at 615 nm. The method obeys Beer's law over a concentration range of 0.15–0.9 g mL-1 iron, having a molar absorptivity of 5.6×104 L mol-1 cm-1 and a Sandell's sensitivity of 0.0001 g cm-2. The optimum reaction conditions and other analytical parameters have been evaluated. The developed method has been successfully applied to the determination of iron in water, soil, industrial effluent, plant material, pharmaceutical preparations, synthetic mixtures, and aluminum alloys. 相似文献
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The violet fluorescence at 480 mmu of lead in concentrated hydrochloric acid-potassium chloride solution (excitation maximum 270 mmu) provides a method for the spectrofluorimetric determination of 10-60mug of lead. The optimum conditions for the determination have been established, and the effect of 31 foreign ions examined at the 50-fold molar excess level. The interference from iron(III) and vanadium(V) is eliminated by addition of tin(II) chloride, and that of chromium(VI) by treatment with sodium sulphite. 相似文献
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Spectrophotometric determination of trace amounts of iron(III) with norfloxacin as complexing reagent 总被引:2,自引:0,他引:2
P B Issopoulos 《The Analyst》1989,114(5):627-630
The complexation of iron(III) with norfloxacin in acidic solution at 25 degrees C, at an ionic strength of about 0.3 M and a pH of 3.0 has been studied. The water-soluble complex formed, which exhibits an absorption maximum at 377 nm, was used for the spectrophotometric determination of trace amounts of iron(III). The molar absorptivity was 9.05 x 10(3) I mol-1 cm-1 and the Sandell sensitivity 6.2 ng cm-2 of iron(III) per 0.001 A. The formation constant (Kf) was determined spectrophotometrically and was found to be 4.0 x 10(8) at 25 degrees C. The calibration graph was rectilinear over the range 0.25-12.0 p.p.m. of iron(III) and the regression line equation was A = 0.163c - 0.00042 with a correlation coefficient of 0.9998 (n = 9). Common cations, except cerium (IV), did not interfere with the determination. The results obtained for the determination of iron(III) using the described procedure and the thiocyanate method were compared statistically by means of the Student t-test and no significant difference was found. 相似文献
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L. M. Polo Diez M. W. Kabbani J. S. Durand Alegria 《Fresenius' Journal of Analytical Chemistry》1989,334(1):41-44
Summary A spectrofluorimetric method is proposed for the determination of gallium with 1-(2-pyridylazo)-2-naphthol as derivative reagent in sodium dodecyl sulphate micellar medium. Sensitivity is increased by a factor of 20 with respect to that obtained in 20% ethanol medium. The stoichiometry of the complex is 11. Optimum working conditions are about pH 4, 0.3% sodium dodecyl sulphate and absence of ethanol. The calibration graph is linear in the range 5–400 ppb of Ga(III) with a variation coefficient of 1.5% at 210 ppb of Ga for 10 replicates, and detection limit is 0.8 ppb. Main interferences are from copper and cobalt. Results obtained in the determination of Ga(III) in urine and aluminium samples show the validity of the method proposed.
Spektrofluorimetrische Bestimmung von Spuren Ga(III) in Aluminium und biologischen Proben mit 1-(2-Pyridylazo)-2-naphthol in micellarem Natriumdodecyl-sulfatmedium相似文献
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Mohammad Reza Ganjali Farhang Mizani Masoud Salavati-Niasari Mehran Javanbakht 《Analytical sciences》2003,19(2):235-238
A plasticized Cr3+ ion sensor by incorporating 2,3,8,9-tetraphenyl-1,4,7,10-tetraazacyclododeca-1,3,7,9-tetraene (TTCT) ionophore exhibits a good potentiometric response for Cr3+ over a wide concentration range (1.0 x 10(-6)-1.0 x 10(-1) M) with a slope of 19.5 mV per decade. The sensor response is stable for at least three months. Good selectivity for Cr3+ in comparison with alkali, alkaline earth, transition and heavy metal ions, and minimal interference are caused by Li+, Na+, K+, Co2+, Hg2+, Ca2+, Pb2+ and Zn2+ ions, which are known to interfere with other chromium membrane sensors. The TTCT-based electrode shows a fast response time (15 s), and can be used in aqueous solutions of pH 3-5.5. The proposed sensor was used for the potentiometric titration of Cr3+ with EDTA and for a direct potentiometric determination of Cr3+ content in environmental samples. 相似文献
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The reaction of 16α-hydroxyestrone with hexacyanoferrate(III) and arginine in alkaline solution at 95°C produces a fluorescent compound that is measured at 490 nm (λ(ex) = 395 nm). Most other steroids do not interfere. The calibration is linear for 0.5–50 μg of analyte. 相似文献
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Summary The fluorescent chelate formed between 1-hydroxy-2-carboxy-anthraquinone and gallium(III) at pH 3.9 has been studied spectrofluorimetrically in an ethanol-water mixture (70/30% V/V). A new method for the fluorimetric determination of gallium(III) is described. The fluorescence is monitored at 580 nm (wavelength of excitation 465 nm) and the range of application of the method is between 50 and 500 ng ml–1. The stoichiometry of the complex has been found to be 11.
Spektralfluorimetrische Bestimmung von Ga(III) mit 1-Hydroxy-2-carboxyanthrachinon
Zusammenfassung Ein neues Verfahren zur fluorimetrischen Bestimmung von Ga(III) mit 1-Hydroxy-2-carboxyanthrachinon bei pH 3,9 in wäßrigem Ethanol wurde ausgearbeitet. Die Fluoreszenz wurde bei 580 nm gemessen (Anregung bei 465 nm). Das Verfahren eignet sich für 50–500 ng/ml. Die Zusammensetzung der Komplexverbindung entspricht dem Verhältnis 11.相似文献
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Summary
Spectropbotometric Determination of Trace Amounts of Iron(III) by Extraction of Mixed-Ligand Iron-Tartrate-Purpurin or Iron-NTA-Purpurin Complex
A selective method is described for the determination of microgram amounts of iron(III) by means of its reaction at pH 9.0 with purpurin (1,2,4-trihydroxyanthraquinone) and tartrate or NTA and extraction into methyl isobutyl ketone. The molar absorptivity of the 112 iron(III)-auxiliary ligand-purpurin complex is 4.8×104 1·mole–1·cm–1 at 595 nm. Beer's law is obeyed from 0.05 to 0.25 ppm of iron in the aqueous phase. Procedures for determination of iron in tartrate or NTA medium, and fluoride-tartrate-NTA medium are given. The method is suitable for determining iron in Zn metal, W metal, NTA, drinking water, wines, urine and tartrates. 相似文献
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Gündüz SB Küçükkolbaşý S Atakol O Kýlýç E 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(5):913-921
In this study, a spectrofluorimetric method has been developed for the determination of aluminum based on the formation of an aluminum complex with N,N'-disalicylidene-1,3-diamino-2-hydroxypropane (DSAHP). The most suitable pH, solvent medium, complex formation time, Schiff base concentration and temperature were determined. The excitation and emission wavelengths were 270 and 437 nm, respectively, in which the DSAHP-Al complex gave the maximum fluorescence intensity at pH 3.0 and 6.0 in 50% dioxan-50% water medium. Under these conditions, calibration curves were obtained in three different linear limits, and was found that aluminum could be detected within the concentration limit of 0-10.0 microM and the lowest detection limit being 0.27 ng ml(-1). The stoichiometry of the DSAHP-Al complex was also determined spectrofluorimetrically under optimal conditions and the molar ratio of DSAHP-Al was calculated as 2:1. Using the developed method, aluminum was detected in hemodialysis solutions, and the results obtained were similar and comparable with those obtained using the method described in the British Pharmacopoeia within 95% confidence limits. This method can be used successfully for the routine determination of aluminum because it is quick, requires less amount of reactives, is sensitive, reliable and reproducible. 相似文献