Univariate and Multivariate Optimization of Spectrophotometric Determination of Europium (III) in Pure Form and Synthetic Sample Wasan Abdil-Wahid Jasim Alaá Kareem Mohammed Rafiá Kadori Atawi Department of Chemistry/ College of Education for Pure Science –Ibn Al Haitham /University of Baghdad Received in : 29 December 2013, Accepted in : 2 February 2014 Abstract Two different approaches, univariate and multivariate (simplex method), have been used to obtain the optimum conditions for the quantitative Spectrophotometric determination of Eu3+ using Solochrome violet RS (3-Hydroxy-4-(2-hydroxy phenyl azo) naphthalene -1- sulfonic acid) (SVRS) as a chromogenic reagent. The investigation shows that Eu3+ ion forms a wine-red complex with SVRS in alkaline buffer solution having a maximum absorbance at 464 nm against reagent blank. Calibration graphs obtained under univariate and simplex were found to be linear in the range of (0.30-8.0) µg/ml with detection limit 0.061µg/ml and molar absorptivity of 9877.66 L/mol.cm and (0.40-10.0)µg/ml with detection limit 0.055µg/ml and molar absorptivity of 10759.05 L/mol.cm respectively. The stoichiometric composition of the formed Eu-SVRS chelate complex is 1:4 (Metal:Ligand). Effect of the presence of some metal ions as interferences was studied and the method has been applied successfully to the determination of cited ion in synthetic sample. Key words: Lanthanides, Simplex, Solochrome Violet(SVRS), spectrophotometric. 198 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 Introduction Rare earth of elements have gained a great attention in the last few decades owing to their unique properties and wide range of applications that utilizes these elements in huge quantities, consequently, data on the total Lanthanide content often suffices in practical problems, particularly when all the Lanthanides beingchemically similar to one another, invariably occur together in the source mineral[1]. Europium is one of the rarest and most costly of the rare earth of elements accounting for only about 0.05 - 0.1 % of the rare earthelements present in the mineral monazite[2]Europium oxide is now widely used as a doping agent inred phosphors activatorandeuropium compounds are also used in color cathode-x-ray tube, liquid-crystal displays used in computer monitor, high-intensity mercury vapor lamps, neutron scintillations, charged-particle, detectors and optically red mercury systems[3]. Various methods such as mass spectrometry (MS), inductively coupled plasma atomic emission spectrometry (ICP-AEC)[4], inductively coupled plasma mass spectrometry (ICP-MS)[5-7], isotope dilution mass spectrometry, neutron activation analysis and x-ray fluorescence spectrometry are viable for low-level determination of rare earth ions in solution, these methods are either time-consuming, involving multiple sample manipulations, or too expensive for most analytical laboratories. On the contrary, UV-visible spectrophotometry is the most convenient techniques because of their inherent simplicity, adequate sensitivity, low cost and wide availability in all quality control laboratories. Azo metal chelates have drawn the attention and can offer an inexpensive and convenient analysis method with metal ions in solution, provided that the acceptable sensitivity and selectivity are achieved[8,9]In experimental chemistry the optimization of technical system is the process of adjusting the control variables to find the levels that achieve the best optimization. Usually many conflicting response must be optimized simultaneously. In lack of systematic approaches the optimization is done by trial and error, or by changing on control variable at a time while holding the rest constant, such methods require a lot of experiments to be carried out. Simplex system was first used to determine the optimal conditions for the variables in the testing process by the researcher Deming[10]and then applied in the field of analytical chemistry by Spendley[11]et al., and modified by Nelder and Mead[12]because it offers the capability of optimizing several factors simultaneously depending on a statistical design search to find the maxima or minima of response, by rejecting the point producing the worst response and a replacement of it by the new point which is obtained statistically. [3-Hydroxy-4-(2-hydroxy phenyl azo) naphthalene -1-sulfonic acid] (SVRS) azo dye, used as metal indicator in the chelatometric determination of Al(III) in natural[13]. In addition, SVRS is a reactive azo dye belonging to the largest class of dyes commonly used in textile industry[14]. The present work describes the utility of Solochrome violet (SVRS) for spectrophotometric determination of Eu3+ and the optimization of chemical spectrophotometric variables of the proposed methods namely pH, reagent concentration and reaction time have been studied by using both classical univariate and modified simplex. 199 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 Experimental Apparatus A Shimadzu (Model 1601 UV-visible spectrophotometer from Shimadzu, Kyoto, Japan) with 1cm quartz cells was used for the absorbance measurement and a pH-meter model BP 3001, (professional benchtop pH meter) was used for all pH measurements. Material and Reagent All chemicals used were of analytical reagent grade or chemically pure grade and double distilled water was used for all dilution of reagents and samples. Preparation of Standard Solution 1. Standard Eu3+ (100 μg.mL-1) was prepared by dissolving 0.0243 gm of Eu2O3 purity (99.5%) Fluka in 20 mL 5 M HNO3 and then then diluted to 200 mL with distilled water. 2. Reagent Solochrome Violet (SVRS) purity (99.5%) Fluka, 1 × 10-3 M solution was prepared by dissolving 0.0367 gm in 100 mL distilled water by using a volumetric flask . Preparation of Buffer Solution Buffer solution (pH=10.4) was prepared by mixing 3.21 gm NH4Cl with 2.24 gm KCl then 22.5 mL of concentrated NH4OH solution was added and diluted to 100 mL with distilled water. Preparation of Synthetic Europium Sample 1. 0.0243 gm of Eu2O3 purity in 20 mL 5 M HNO3 and then then diluted to 200 mL with tap water (100 μg.mL-1 Eu3+). 2. 10 mL of stock 100 μg.mL-1 Eu3+ was diluted to obtain 100 mL of 10 μg.mL-1 Eu3+ working solution. General Procedure According to Univariate Optimization An aliquot of the standard solution containing no more than ( 3 - 80 µg) was transferred into a series of 10 mL volumetric flasks, to each flask 1mL of 2.6 × 10-3 M of (SVRS) complexing agent followed by the addition of 1 mL of buffer solution (pH=10.4), then the resultant solutions was made up to 10 mL with distilled water. The absorbance was measured at 464 nm after 10 min against a reagent blank. All measurements were made at room temperature (25.0 ± 0.5). A calibration graph of the absorbance versus the concentration of Eu+3 was plotted. General Procedure According to Simplex Optimization Accurately measured aliquot of Eu3+ solution containing(4 – 100 µg) were transferred into 10 mL volumetric flask, 1mL of( 3 × 10-3 M) of SVRS-reagent was added followed by( 1.4 mL) of buffer solution (pH=10.4), then the mixture was completed to final volume and the resultant solution was measured at 464 nm after 15 min against a reagent blank treatedsimilarly. 200 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 Results and Discussion The optimization of the method was carefully studied in order to achieve complete reaction formation, highest sensitivity and maximum absorbance. Spectral Characteristics of Eu3+ –SVRS Complex Under the conditions used, Eu+3 ions and RS reagent form a red-pink complex with an absorption maximum at 464 nm at pH = 9.42 against the reagent blank (Fig. 1). The reaction between Eu3+ ion and the SVRS-reagent is rapid and instantaneously and the color obtained remained strictly stable for at least 2 hours. Optimization of Experimental Variable i. Univariable Method The goal of this investigation was to find a simple, reliable and accurate method for the determination of the cited ion under study, so several parameters such as pH, reaction time reagent concentration, and order of mixing were optimized to achieve the best results. For this reason a variable was modified while maintaining the other variable at their constant value, then by maintaining that variable at its optimized value another was modified, all variable were optimized via this method. Effect of Volume of Buffer To study the effect of the volume of the pH on the absorbance of the complex formation, varying volumes of standard buffer (pH =10.4) in the range (0.2 - 1.2 mL) were added and measuring the absorbances of the solutions (Fig 2). Maximum color intensity of the complex was achieved with 1mL of the buffer solution, which remained unaffected by further volume additions of buffer solution due to completeness of the reaction. Effect of Reagent Concentration The influence of the concentration of reagent on the development of color was investigated by treating varied concentrations (1 × 10-3 - 3.2 × 10-3M) of reagent solution (Fig. 3). It was observed that the absorbance measured at 464 nm increased with the increase of concentration of reagent and became constant at 2.6 × 10-3 M due to the high stability of the complex, above this concentration no more increase in absorbance values was obtained, therefore, the cited concentration of reagent solution were used. Effect of Time on the Stability of the Formed Complex The reaction is instantaneous ,and the Eu+3-reagent complex attained maximum and constant absorbance at 10min and remained constant up to 30min (Fig 4); therefore ,10 min of development time was selected as optimum through out the determination process. 201 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 Effect of Order of Addition Different orders were used to mix the solutions of the reagent used in this investigation. It was found that the addition of the reagent solution followed by the buffer solution to the Eu3+ solution (order 1 in table 1) gave the best results. ii. Simplex Method Simplex method is used to confirm the optimum conditions, which were obtained by the univariate procedure. To set the simplex optimization of the three major studied variables (reagent concentration, volume of buffer and standing time). Four experimental conditions should be chosen and the values of these variables were selected within specified boundaries for each at which it affects the absorption signal of the colored product (Table 2). The absorbances of these four initial experiments were measured and the results were fed to the computer program (Table 3). The program then started simplex by searching the worse absorption signal and reflected it in hyper-plane of the remaining points to produce a new set of experimental conditions, which were applied to carry out experiment and the measured absorption signal was fed again to the program. The process is repeated successively until optimum conditions were obtained (i.e. conditions yielding highest absorption signal). The procedure continued for further few experiments to ensure that the optimum conditions are reached similarly to those obtained by the univariate method. Stoichiometry of the Complex The stoichiometry of the complex was studied by the mole ratio method. A series of solutions were prepared by addition of varying amounts of reagent (SVRS) 6.026 - 60.26 µg to a constant amount of Eu3+ 50 µg. To each solution 1.4 mL of standard buffer solution was added and the resulted solutions were diluted up to the 10 mL with distilled water, then the absorbances were measured at 464 nm after 15 min against the reagent blank solution and plotted against the ratio of [Reagent SVRS ] / [Eu3+] (Figure 5). Figure 5, shows that the mole ratio of Eu3+: SVRS in the complex is 1:4, therefore a structure of the complex could be proposed as shown in the following scheme. Analytical Data and Calibration Graph Employing the optimum experimental condition (under univariate and simplex conditions), two calibration graphs, Figures 6 and 7 respectively, for the determination of Eu3+ at 464 nm were obtained. Table (4) shows a brief comparison between the two recommended procedures. It is obvious, that the conditions obtained under multivariate simplex optimization gave better results; therefore these conditions were followed in subsequent work. Accuracy and Precision The accuracy of the proposed method was confirmed by performing five replicate analysis for three different amounts of Eu3+ (selected within Beer’s Law) by calculating the relative error percentage (Table 5). The results indicated good accuracy of the method at each concentration level. The precision was determined in each case by calculating the percentage relative standard deviation (RSD %) for three 202 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 determinations at each of the studied concentrations and level and were found to be in the range of 0.63- 1.68. Effect of Foreign Ions: The effect of presence of some foreign ions on the trace level determination of Eu3+ has been studied. The results are depicted in table 6 which indicate that the studied ions have significant effect on the determination of the cited ion, so that prior separation would be essential. Otherwise, standard addition method must be followed for such purpose. Standard Addition Method The proposed method was applied to determine synthetic europium sample by standard addition technique according to following procedure: Varying aliquots (0, 0.2, 0.4, 0.8, 1.0, 1.4, 2.0 mL) of standard 10 μg.mL-1 Eu3+ solution were added to seven 10 mL volumetric flasks each of them contains 0.5 mL of the unknown (the synthetic europium sample solution), followed by addition of 1mL of 3 × 10-3 M of SVRS-reagent and 1.4 mL of buffer solution (pH=10.4). Each mixture was then diluted to final volume via distilled water and the absorbance was measured at the recommended wavelength after 15 min against its reagent blank (Fig. 8)-. References 1. Gschneidner,K.A. and Eyring,L.(1981) Handbook on the physics and chemistry of Rare earth , Elsevier ,Amsterdam. 2. Per Enghag,(2004) Encyclopedia of the elements: Technical data, history, processing, and applications. John Wiley and sons, page 450. 3. Haxel,G.; Hedrick and Orris, J. (2008) Rare earth elements critical resources for high technology. Reston(A):United states Geology survey .USGS Fact sheet . 4. Pei Liang and Yan. Li Guo. (2005) Determination of trace rare earth elements by inductively coupled plasma atomic emission spectrometry after preconcentration with multiwalled carbon nanotubes. Fuel, vol. 60, issue 1, 10 January, pages 125-129. 5. Zhang, N.; Huang, C.and Hu, B. (2007) ICP-AES.,Determination of trace rare earth elements in environmental and food samples by on-line separation and preconcentration with acetylacetone modified silica gel using microgram. Anal.sci,23(8):997-1002. 6. Akinluam, J.A.;Torto,N.and Ajayi,T. R.(2008) Determination of rare earth elements in Niger Delta cmde oils by inductively coupled plasma-mass spectrometry. Fuel, vol 87, issue 8, July, page 1469-1477. 7. Zhang ,A.; Liu, y.and Zhang, W. (2004) Determination of rare earth impurities in high purity europium Dxide by inductively coupled plasma –mass spectrometry and evaluation of concentration values for europium oxide standard material, Eur. J. Mass spectro., 10 (5), page 589-598. 8. Wang, S.P.; Shen, S. and Xu, H. (2000) Synthesis spectroscopic and therma (properties of a series. Fazo metal chelate dyes pigments. 44, P; 195. 9. Wanger, J. B.; Sonia, R. G.; Ieda, S. S.; Dilson, N. I.and Miriam, de. F. (2010) Determination of Ni2+ in metal alloys by spectrophotometry UV–visible using Dopasemi-quinone, Quim. Nova, Vol. No ,1 ,109-113 . 203 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 10. Deming, S. N.and Morgan ,S.L. (1973) Simplex optimization of variables in analytical chemistry, Anal. Chem.; 45 (3); 278-283. 11. Spendly, W.; Hext, G.R.and Himswarth, F.R. (1962) Sequential application of simplex design in optimization and evolutionary operation, Technomertics; 4; 441-402 . 12. Nelder, J. A.and Mead, R. A. (1965) A simplex method for function minimization, Computer J .7; 308-313 . 13. Wang ,X.; Lei, J.and Gan, S. (2001) Determination of the speciation of Al3+ in natural waters by adsorption stripping voltammetry and complexation with Solochrome Violet RS, Analytica Chimica Acta,1, page 499 (2001). 14. Mrowetz, M.and Selli, E., Enhanced photocatlytic formation of hydroxyl radicals on fluorinated TiO2. phys. Chem:7:1100. Figure( 1): Absorption spectra of (a) 10 µg.mL-1 Eu3+, 3 × 10-3 M reagent at pH 9.40 against blank reagent, (b) 3 × 10-3M reagent at pH 9.40 against distilled water. Figure( 2): Effect of buffer volume. 0.54 0.56 0.58 0.6 0.62 0.64 0 0.5 1 1.5 A bs or ba nc e Buffer volume (mL) Figure( 3 ) : Effect of reagent Concentration Figure (4): Effect of time on the stability of the formed complex. Figure( 5): Mole ratio method for 3.29 × 10-5 M Eu3+ with variable concentrations of reagent at pH = 9.4. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 0.001 0.002 0.003 0.004 A bs or ba nc e Reagent Concentration (M) 0.58 0.59 0.6 0.61 0.62 0 10 20 30 40 A bs or ba nc e Time (min.) 205 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 Figure (6): Calibration curve for the determination of Eu 3+ under optimum conditions obtained via univariate optimization. Figure (7): Calibration curve for the determination of Eu 3+ under optimum conditions obtained via multivariate simplex optimization. Figure (8): Standard addition plot for the determination of Eu3+ in synthetic sample. y = 0.0671x + 0.0102 R² = 0.9 0 0.1 0.2 0.3 0.4 0.5 0.6 0 2 4 6 8 10 A bs or ba nc e Concentartion (μg.mL-1) y = 0.0708x + 0.0031 R² = 0.9 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 2 4 6 8 10 12 A bs or ba nc e Concentartion (μg.mL-1) y = 0.0298x + 0.0784 R² = 0.9993 y = 0.0298x + 0.0784 R² = 1 A bs or ba nc e Volume of standard (mL) Vs = - 2.6308 mL 206 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 Table ( 1): Effect of sequence of addition on the absorbances of 10µg.mL-1 (Eu+3), 2.6x10- 3M at pH=9.4. Absorbance Types of mixing 0.613 Buffer Reagent Metal Order 1 0.569 Reagent Buffer Metal Order 2 0.609 Metal Buffer Reagent Order 3 Table ( 2):Boundary conditions for the studied variables. Table (3):Absorbance of each of the simplexes in the optimization of color development for determination of Eu3+. Range Variable 1.2 - 3.0 Reagent concentration M ×10-3 0.1 - 1.4 Buffer volume (mL) 0.0 – 30 Standing time (min) Absorbance Time (min) Vol. of buffer ( mL) Reagent Conc. ×10-3 M Exp. No. 0.2888 5 0.5 1.2 1 0.5142 0 1.4 2.0 2 0.6330 30 0.8 2.6 3 0.6524 10 1.0 3.0 4 0.6607 20 1.4 3.0 5 0.6802 30 1.0 3.0 6 0.7127 15 1.4 3.0 7 0.6743 30 1.4 3.0 8 0.6925 25 1.2 3.0 9 0.6848 10 1.2 3.0 10 0.6610 5 1.4 3.0 11 0.7002 30 1.4 3.0 12 0.6607 20 1.2 3.0 13 207 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 Table (4): comparison between the two recommended procedures. Simplex optimization Univariate optimization Condition 3.0x10-3 2.6x10-3 Conc. of reagent(mol.L -1) 1.4 1.0 Volume of buffer (mL) 15 10 Stability of complex(min) A=0.0708[Eu3+]µg.mL-1+0.0031 A=0.065[Eu3+]µg.mL-1 +0.013 regression equation 0.055 0.3013 Detection limit (µg.mL-1) 10759.051 9877.66 ε (L.mole -1cm-1) 0.4-10 0.3-8.0 Calibration range (µg.mL-1) Table (5): Evaluation of accuracy and precision of the proposed method. Concentration (µg/mL) R.E. % R.S.D % Taken Found 1 0.96 -3.78 1.68 5 5.11 2.17 0.93 8 8.22 2.78 0.63 Table (6):Determination of (6.0µg/ml) of Eu3+ in the presence of foreign ions. Interfering ion Eu+3 (6 µg.mL-1) Taken (µg.mL-1) Ratio RE% Cr3+ 6 1:1 -20.44 60 10:1 -86.94 Fe3+ 6 1:1 -82.71 60 10:1 -77.95 Co2+ 6 1:1 -64.46 60 10:1 -70.38 Cu2+ 6 01:1 -64.46 60 10:1 -70.38 Mg2+ 6 1:1 -13.60 60 10:1 -75.09 Na+ 6 1:1 -5.02 60 10:1 0.52 300 50:1 -3.26 600 100:1 -1.58 208 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 N O NHO S OO O Na N O N OH S O O O Na N O NHO S OO O Na N O N OH S O O O Na Eu Scheme (1): The proposed structure of Eu3+ –SVRS complex. 209 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014 االحادیة والمتعددة للتقدیر الطیفي الیون الیوربیوم الثالثيیات الظروف الفضل مصنعنموذج أالنقیة وفي ھفي حالت وسن عبد الواحد جاسم عالء كریم محمد رافع قدوري عطیوي ابن الھیثم/جامعة بغداد-قسم الكیمیاء/كلیة التربیة للعلوم الصرفة 2014شباط 2 ، قبل البحث في : 2013كانون األول 29استلم البحث في : الخالصة للتقدیر الطیفي الكمي الیون الیوربیوم الثالثي باستخدام الكاشف یاتللوصول الى الظروف الفضل اناسلوبأُتبع مع اً شرابی اً احمر اً .اظھرت الدراسة ان ایون الیوربیوم یكون معقد Solochrome Violet(SVRS)الكروموجیني .امكن خلبنانومیتر مقابل المحلول ال464 الكاشف في وسط قلوي ویظھر محلولھ امتصاص اعظم عند الطول الموجي المتغیر الواحد والسمبلكس ھما التي تم الحصول علیھا باسلوبین یاتالحصول على منحنیي معایرة باتباع الظروف الفضل وامتصاصیة موالریة مقدارھا ،مایكروغرام/مل 0.3) مایكروغرام/مل وحد كشفي مقدارة 0.3-8.0( هوبمجال خطي مقدار ه مایكروغرام/مل وحد كشفي مقدار )(0.40-10.0 هالسلوب االول وبمدى خطیة مقدارالى التر/مول.سم بالنسبة 9877.66 سمبلكس.لتر/مول.سم باسلوب ال10759.05مایكروغرام/مل وامتصاصیة موالریة مقدارھا 0.055 درس تاثیر وجود ایونات ثم ، 1:4ان نسبة الكاشف الى العنصر كانت ،اظھرت دراسة تكافؤیة المعقد الكلیتي المتكون نموذج مصنع.أتقدیر العنصر وطبقت الطریقة المقترحة لتقدیر كمیتھ في في مختلفة المطیافیة.الالنثانات، السمبلكس، سولوكروم فایولیت، الكلمات المفتاحیة: 210 | Chemistry @a@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@Ü‹127@@ÖÜ»€a@I2@‚b«@H2014 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 27 (2) 2014