scholarly journals Extraction and separation studies of zinc(II) and copper(II) with D2EHPA and PC-88A from perchlorate media

2002 ◽  
Vol 67 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Rajeev Singh ◽  
Purshottam Dhadke
Keyword(s):  
Phosphoric Acid ◽  
Organic Phase ◽  
Real Samples ◽  
Extraction And Separation ◽  
Ph Range

The extraction behaviors of Zn(II) and Cu(II) from perchlorate media have been investigated using bis-2-ethylhexyl phosphoric acid (D2EHPA) and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester, (PC-88A) in toluene. The extraction of Zn(II) was found to be quantitative in the pH range 2.5 to 3.0 and 3.0 to 4.0 using 1.0 x 10-1 moldm-3 D2EHPAand 1.0x10-2 mol dm-3 PC-88Ain toluene, respectively, while Cu(II) was extracted quantitatively in the pH range 6.0 to 8.0 and 5.5 to 7.0 with 1.0x10-2 mol dm-3 and 1.0 x 10-3 mol dm-3 D2EHPA and PC-88A in toluene, respectively. Zn(II) was stripped with 4.0 moldm-3 HCl, while Cu(II) with 2.0 moldm-3H2SO4 and 3.0 moldm-3 HNO3 from the organic phase containing D2EHPAand PC-88A respectively. The probable extracted species were ascertained by log D vs. log [HR] plot to be ZnR2.2HR and CuR2.2HR for both the reagents. These methods were used for the determination of Zn(II) and Cu(II) in real samples. The separation of Zn(II) and Cu(II) were carried out from each other and with associated metals.

Kinetics of solvent extraction of metal ions with HEDHP. III. The kinetics and mechanism of solvent extraction of Cr(III) from acidic aqueous solutions with bis-(2-ethyl hexyl) phosphoric acid in benzene

1979 ◽  
Vol 57 (23) ◽  
pp. 3011-3016 ◽  
Author(s):  
Muhammad Fakhrul Islam ◽  
Ranjit Kumar Biswas
Keyword(s):  
Solvent Extraction ◽  
Phosphoric Acid ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Forward Rate ◽  
Nitrate Ions ◽  
Rate Determining Step ◽  
Ethyl Hexyl ◽  
Ph Range ◽  
Kinetics Of

The rate of solvent extraction of chromium(III) from aqueous sulphuric acid solutions (containing 0.05 mol dm−3 sulphate ion and 0.25 mol dm−3 acetate buffer, ionic strength, I = 0.40 mol dm−3) with bis-(2-ethyl hexyl) phosphoric acid (HDEHP or H2A2) in benzene has been measured under various conditions. The rate of backward extraction measurement of Cr(III) from organic phase to aqueous phase is not possible due to the inert property of Cr(III)–DEHP chelate. The forward rate is found to be first-order w.r.t. Cr(III) concentration in the aqueous phase and HDEHP concentration in the organic phase. The order w.r.t. H+ concentration varies from −1 to 1 over the pH range 1.5 to 5.25. The rate is found to decrease with increasing sulphate and nitrate ions concentrations in the aqueous phase. At (30 ± 1) °C, the rate expression, in the presence of sulphate, acetate, and nitrate ions, is found to be represented by:[Formula: see text]In the absence of the anions, the formation of CrHA22+ intermediate complex (Cr(OH)2+ + H2A2(0) → CrHA22+ + H2O) is the rate determining step at all acidities. The effects of the anions on the rate are discussed.

scholarly journals Extraction and separation studies of Ga(III), In(III) and Tl(III) using the neutral organophosphorous extractant, Cyanex-923

2003 ◽  
Vol 68 (7) ◽  
pp. 581-591 ◽  
Author(s):  
S.D. Pawar ◽  
P.M. Dhadke
Keyword(s):  
Metal Ions ◽  
Organic Phase ◽  
Acidic Solution ◽  
Sequential Procedure ◽  
Analysis Method ◽  
Effect Of Ph ◽  
Extraction And Separation ◽  
Slope Analysis ◽  
Cyanex 923 ◽  
Ph Range

The neutral extractant, Cyanes-923 has been used for the extraction and separation of gallium(III), indium(III) and thallium(III) from acidic solution. These metal ions were found to be quantitatively extracted with Cyanex-923 in toluene in the pH range 4.5?5.5, 5.0?6.5 and 1.5?3.0 respectively, and from the organic phase they can be stripped with 2.0 mol dm-3 HNO3, 3.0 mol dm-3 HNO3 and 3.0 mol dm-3 HCl, respectively. The effect of pH equilibration period, diluents, diverse ions and stripping agents on the extraction of Ga(III), In(III) and Tl(III) has been studied. The stroichiometry of the extracted species of these metal ions was determined on the basis of the slope analysis method. The reaction proceed by solvation and the probable extracted species found were [MCl3. 3Cyanex-923]?[where M = Ga(III) or In(III)]?and [HTlCl4. 3Cyanex-923]. Based on these results a sequential procedure for the separation of Ga(III), In(III) and Tl(III) from each other was developed.

scholarly journals Extractive Spectrophotometric Determination of Pd(II) with Sodium Salt of Hexamethyleneiminecarbodithioate

2013 ◽  
Vol 23 ◽  
pp. 20-28
Author(s):  
S.D. Dhanavate ◽  
D.J. Garole ◽  
V.J. Garole ◽  
S.R. Tetgure ◽  
A.D. Sawant
Keyword(s):  
Metal Ions ◽  
Spectrophotometric Determination ◽  
Sodium Salt ◽  
Accurate Determination ◽  
Chelating Agent ◽  
Molar Absorptivity ◽  
Real Samples ◽  
Highly Sensitive ◽  
Ph Range

The reagent NaHMICdt·2H2O has found to be a good chelating agent for the spectrophotometric determination of various metal ions. The present investigation deals with spectrophotometric determination of Pd(II) by using NaHMICdt·2H2O. The reagent reacted with Pd(II) to give yellow complex extractable into toluene. Pd (II) was extracted quantitatively in the pH range 0.5-2.0. Pd(II)-HMICdt complex showed λmax at 435 nm. The extracted species has a 1:2 (M:L) stoicheometry. Beer’s law is obeyed in the range of 0.2-0.8 μg ml-1 of Pd (II). The molar absorptivity and the sandells sensitivity were found to be 0.754 x 104 lmol-1cm-1 and 0.0140 μg mol-1 cm-2 respectively. The effect of divers ion on the extraction of Pd(II) has been investigated. The proposed method is highly sensitive, selective, and simple and rapid has been applied for accurate determination of palladium in synthesis mixtures and real samples.

Spectrophotometric determination of zinc with 5-methyl-1,3,4-thiadiazolyl-(2-azo-1)-2-naphthol

1983 ◽  
Vol 48 (2) ◽  
pp. 464-470 ◽  
Author(s):  
Juan Cacho ◽  
Cristina Nerin
Keyword(s):  
Spectrophotometric Determination ◽  
Organic Phase ◽  
Molar Absorptivity ◽  
Beer's Law ◽  
Optimum Ph ◽  
Beer’S Law ◽  
Ph Range ◽  
Optimum Ph Range

The reaction of Zn(II) with 5-methyl-1,3,4-thiadiazolyl-(2-azo-1)-2-naphthol (MTDAN) and extraction of the complex formed in chloroform is studied. The optimum pH range for the extraction and formation of the complex is 10-11.2 and Beer's law is obeyed in the interval of 0-2 ppm of Zn(II) in the organic phase. The molar absorptivity is 5.9 . 104 l mol-1 cm-1 at 568 nm. The stoichiometry of the complex corresponds to the type ML2. Some interferences are studied and an easy way is given to eliminate them. The results are compared with those corresponding to TAN. The reaction is applied to the analysis of synthetic samples of bronzes with satisfactory results.

scholarly journals Liquid Anion Exchange Chromatographic Extraction and Separation of Platinum(IV) with n-Octylaniline as a Metallurgical Reagent: Analysis of Real Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ashwini P. Gaikwad ◽  
Ganesh S. Kamble ◽  
Sanjay S. Kolekar ◽  
Mansing A. Anuse
Keyword(s):  
Back Extraction ◽  
Extractant Concentration ◽  
Selective Method ◽  
Real Samples ◽  
Extraction And Separation ◽  
Slope Analysis ◽  
Masking Agents ◽  
Comparison Of The Results ◽  
Chromatographic Extraction

A simple and selective method was developed for the determination of platinum(IV) with n-octylaniline in toluene. In present study, the use of n-octylaniline in toluene for the extraction of platinum(IV) from ascorbate media was carried out. The effect of various parameters, such as pH, equilibrium time, extractant concentration, and organic solvent on the extraction has been discussed. The back extraction of platinum(IV) has been performed. On the basis of slope analysis, the composition of the extracted species was determined as [RR′NH2+Pt(Succinate)2−](org). The interfering effects of various cations and anions were also studied, and the selectivity of the method is enhanced by using suitable masking agents. The proposed method is rapid, reproducible and successfully applied for the determination of platinum(IV) in binary and synthetic mixtures. The separation of pt(IV) from other associated metals has been studied. Comparison of the results with those obtained using an atomic absorption spectrophotometer also tested the validity of the method.

EINE CHEMISCHE METHODE ZUR BESTIMMUNG VON 16-EPI-ÖSTRIOL IM URIN DES MENSCHEN

1963 ◽  
Vol 44 (1) ◽  
pp. 47-66 ◽  
Author(s):  
W. Nocke ◽  
H. Breuer
Keyword(s):  
Melting Point ◽  
Phosphoric Acid ◽  
Aqueous Alkali ◽  
Percentage Error ◽  
Organic Layer ◽  
Maximum Percentage ◽  
Chemical Determination ◽  
Routine Assay ◽  
Hydrolysis Of

ABSTRACT A method for the chemical determination of 16-epi-oestriol in the urine of nonpregnant women with a qualitative sensitivity of less than 0.5 μg/24 h is described. The separation of 16-epi-oestriol and oestriol is accomplished by converting 16-epi-oestriol into its acetonide, a reaction which is stereoselective for cis-glycols and therefore not undergone by oestriol as a trans-glycol. Following partition between chloroform and aqueous alkali, the acetonide of 16-epi-oestriol is completely separated with the organic layer whereas oestriol as a strong phenol remains in the alkaline phase. 16-epi-oestriol is chromatographed on alumina as the acetonide and determined as a Kober chromogen. This procedure can easily be incorporated into the method of Brown et al. (1957 b) thus making possible the simultaneous routine assay of oestradiol-17β, oestrone, oestriol and 16-epi-oestriol from one sample of urine. The specificity of the method was established by separation of 16-epi-oestriol from nonpregnancy urine as the acetonide, hydrolysis of the acetonide by phosphoric acid, isolation of the free compound by microsublimation and identification by micro melting point, colour reactions and chromatography. The accuracy of the method is given by a mean recovery of 64% for pure crystalline 16-epi-oestriol when added to hydrolysed urine in 5–10 μg amounts. The precision is given by s = 0.24 μg/24 h. For the duplicate determination of 16-epi-oestriol the qualitative sensitivity is 0.44 μg/24 h, the maximum percentage error being ± 100% The quantitative sensitivity (±25% error) is 1.7 μg/24 h.

Determination of trace amounts of cobalt by homogeneous isotope exchange in an organic phase

1980 ◽  
Vol 45 (12) ◽  
pp. 3332-3337
Author(s):  
Václav Jiránek
Keyword(s):  
Organic Phase ◽  
Isotope Exchange ◽  
Radiochemical Method

A new radiochemical method for determining trace amounts of cobalt has been worked out. It is based on a homogeneous isotope exchange between cobalt(III) diethyldithiocarbamate and cobalt(III) caprate in an organic phase. The method, tested in the range 0.005-8 μg Co, has proved to be selective.

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

Sorption of Lead by the Selective Ion Exchanger Ostsorb DETA

1992 ◽  
Vol 57 (7) ◽  
pp. 1393-1404 ◽  
Author(s):  
Ladislav Svoboda ◽  
Jan Uhlíř ◽  
Zdeněk Uhlíř
Keyword(s):  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Ion Exchanger ◽  
Preconcentration Procedure ◽  
Bead Cellulose

The properties of Ostsorb DETA, a selective ion exchanger based on modified bead cellulose with chemically bonded diethylenetriamine functional groups, were studied, and its applicability to the preconcentration of trace amounts of lead from aqueous solutions was verified. The conditions of the preconcentration procedure in the column and batch modes were optimized for this purpose. The results obtained were applied to the determination of lead in phosphoric acid.

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