scholarly journals DISTRIBUTION OF IRON (II) BETWEEN BUFFERED AQUEOUS SOLUTIONS AND CHLOROFORM SOLUTION OF N,N’-ETHYLENEBIS(4-BUTANOYL-2,4-DIHYDRO-5-METHYL-2-PHENYL-3H-PYRAZOL-3-ONEIMINE)

2012 ◽  
Vol 8 (2) ◽  
pp. 1581-1589 ◽  
Author(s):  
J. Godwin ◽  
U. J. Chukwu ◽  
T. D. Gad
Keyword(s):  
Aqueous Solution ◽  
Organic Phase ◽  
Chloroform Solution ◽  
Slope Analysis ◽  
Mixed Ligands ◽  
Quantitative Extraction ◽  
Before And After ◽  
Extraction Parameters ◽  
Ph Range ◽  
Optimal Ph

The distribution of Fe(II) between buffered aqueous solution and chloroform solution of N,N’-Ethylenebis(4-butanoyl-2-4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-oneimine)(H2BuEtP) was investigated. The effect of 4-butanoyl-2-4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one(HBuP) in the distribution was also studied. Fe(II) concentration in aqueous raffinate was determined colorimetrically and distribution ratios and percentage extractions calculated by difference from Fe(II) in aqueous phase before and after equilibrations. The optimal pH for Fe(II) distribution slightly lowered to 8.00 in mixed ligands(H2BuEtP/HBuP) organic phase from 8.25 in ligand (H2BuEtP) alone organic phase. The pH range at which quantitative extraction of Fe(II) from aqueous buffered solution into both type of organic phases used for the study was very narrow. The extraction parameters; pH1/2, log D from extraction plots, and log Kex calculated using extraction equations derived from slope analysis showed that the values in both type of organic phases were very close even though mixed ligands(H2BuEtP/HBuP) organic phase values were slightly higher and better. Slope analysis also indicated that the Fe(II) complexes extracted into both organic phases were Fe(BuEtP)o and Fe(HBuEtP)(BuP)o respectively.

Preparation of Gold Nanoparticles by Using Cholesteryl Compounds

2013 ◽  
Vol 368-370 ◽  
pp. 795-798
Author(s):  
Zhen Dong Wu
Keyword(s):  
Aqueous Solution ◽  
Gold Nanoparticles ◽  
Organic Phase ◽  
Chloroform Solution ◽  
Reducing Agents ◽  
Liquid Interface ◽  
Gold Nanostructures ◽  
Molar Ratios

Gold nanoparticles were synthesized by two bolaform cholesteryl imide derivatives with different lengths of ethyleneamine spacers at a liquid-liquid interface. By stirring the aqueous solution containing AuCl4- ions with the chloroform solution of bolaform amphiphile, AuCl4- ions were transferred into the organic phase and reduced to gold nanoparticles. Spectral and morphological measurements indicated that both bolaform amphiphiles could serve as both capping and reducing agents. Different gold nanostructures could be obtained depending on the different spacers and the molar ratios of amphiphile to AuCl4- ions.

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 Acids and Anions Effects on the Distrubution of Cadmium Between Buffered Aqeuous Phases and 4,4´-(1e,1e´)-1,1´-(Ethane-1,2-Diylbis (Azan-1-Yl-1ylidene)) Bis(5-Methyl-2-Phenyl-2,3-Dihydro-1h-Pyrazol-3-Ol) Solutions

2019 ◽  
Vol 35 (6) ◽  
pp. 1702-1711
Author(s):  
J. Godwin ◽  
L. S. Tella ◽  
A. N. Ebelegi ◽  
N. Ayawei
Keyword(s):  
Chloroform Solution ◽  
Atomic Absorption Spectrophotometry ◽  
Metal Extraction ◽  
Complexing Agents ◽  
Equilibration Time ◽  
Mixed Ligands ◽  
Flame Atomic Absorption ◽  
Before And After ◽  
The Difference ◽  
High Concentrations

The effect of some acids, anions and auxiliary complexing agents on the extraction of Cadmium (II) from aqueous solutions buffered to pH 7.5 using a chloroform solution of the Schiff base ligand 4,4´-(1E,1E´)-1,1´-(ethane-1,2-diylbis(azan-1-yl-1ylidene))bis(5-methyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-ol) (H2BuEtP) alone and in the presence of 1-(3-hydroxy-5-methyl-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) butan-1-one (HBuP) after an equilibration time of sixty minutes was investigated. Working concentration of Cd(II) was 50mgL-1, while a range from 0.001M-3.0M was used for acid and 0.001M-1.0M for anions and auxiliary complexing agents. Extraction raffinates were analysed for Cd(II) using Flame Atomic Absorption spectrophotometry and Distribution Ratios. Percentage Extractions (%E) were calculated by difference of Cd(II) concentrations before and after equilibration. The mixed ligands H2BuEtP/HBuP organic phase was a better extractant for Cadmium than H2BuEtP alone but the difference was not significant for all acids, Cl-, Oxalate and Tartrate. The results indicated that at lower concentrations of the acids, anions and auxiliary complexing agents, a releasing effect occurred with improved extraction of Cadmium > 90% in most cases and at high concentrations there was reduced percentage extraction due to masking of Cadmium from formation of stable salts of Cadmium. Comparing results with other those of other metals studied under same conditions showed that multi-metal extraction with the ligand (H2BuEtP) is possible. H3PO4, H2SO4, HCl, PO43-, EDTA and Oxalate all showed theoretical potentials for separating Cadmium from other studied metals with Separation Factors βxy = Dx/Dy close to and above 104.

Evaluation of Metal Contents in Correlation with Phytosanitary Treatments at Vineyard

2017 ◽  
Vol 68 (6) ◽  
pp. 1289-1293
Author(s):  
Oana Mihai ◽  
Octav Pantea ◽  
Daniela Roxana Popovici ◽  
Catalina Gabriela Gheorghe
Keyword(s):  
Soil Samples ◽  
Flame Atomic Absorption ◽  
Mobile Forms ◽  
Before And After ◽  
Phytosanitary Treatment ◽  
Zinc Concentrations ◽  
Zinc Levels ◽  
Ph Range ◽  
In The Beginning ◽  
Short Time

The present work aims with the evaluation of copper, manganese and zinc concentrations (mobile forms) from vineyard soil before and after phytosanitary treatment with Curzate Manox and Dithane M-45 compounds, during and after remanence period. Different vineyard soils types were collected at 0-20 cm and 20-40 cm depths. Flame Atomic Absorption Spectroscopy (FAAS) method was used for measurements of the micronutrients. The soil samples were analyzed after 5 and 21 days after treatment application. Since copper is mainly accumulates in the upper layer following fungicidal sprays application, high levels of copper concentrations are obtained. The soil samples exhibits different behavior in terms of manganese and zinc contents. Manganese and zinc levels are classified as medium in the beginning of the experiment (Mn-M0 and Zn-M0), whereas these levels increased in the soil samples (at moments M1- 5 days and M2- 21 days after treatment). This behavior can be due to the Mancozeb decomposition, knowing that Mancozeb decomposes in the pH range 5-9 and it remains short time into the soil.

Schiff base equilibria. II. Beryllium complexes of N-n-butylsalicylideneimine and the hydrolysis of the Be2+ ion

1965 ◽  
Vol 18 (5) ◽  
pp. 651 ◽  
Author(s):  
RW Green ◽  
PW Alexander
Keyword(s):  
Aqueous Solution ◽  
Schiff Base ◽  
Complex Formation ◽  
Distribution Coefficient ◽  
Dilute Aqueous Solution ◽  
The Stability ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Beryllium Complexes ◽  
Equilibria In Aqueous Solution

The Schiff base, N-n-butylsalicylideneimine, extracts more than 99.8% beryllium into toluene from dilute aqueous solution. The distribution of beryllium has been studied in the pH range 5-13 and is discussed in terms of the several complex equilibria in aqueous solution. The stability constants of the complexes formed between beryllium and the Schiff base are log β1 11.1 and log β2 20.4, and the distribution coefficient of the bis complex is 550. Over most of the pH range, hydrolysis of the Be2+ ion competes with complex formation and provides a means of measuring the hydrolysis constants. They are for the reactions: Be(H2O)42+ ↔ 2H+ + Be(H2O)2(OH)2, log*β2 - 13.65; Be(H2O)42+ ↔ 3H+ + Be(H2O)(OH)3-, log*β3 -24.11.

Effects of Aging on the Solubility of Palladium

1995 ◽  
Vol 412 ◽  
Author(s):  
C. Oda ◽  
H. Yoshikawa ◽  
M. Yui
Keyword(s):  
Aqueous Solution ◽  
Aging Time ◽  
Room Temperature ◽  
High Level Waste ◽  
Anaerobic Conditions ◽  
Dilute Aqueous Solution ◽  
Waste Repository ◽  
Ph Range ◽  
Effects Of Aging ◽  
High Level

AbstractPalladium solubility was measured in a dilute aqueous solution at room temperature in the pH range from 3 to 13 under anaerobic conditions. Crystalline Pd metal was clearly visible and the concentration of palladium in solution decreased gradually with aging time. The palladium concentrations in solution were less than 9.4×10-10M in the pH range from 4 to 10 and increased to 10-7M in the pH range greater than 10. This study suggests that palladium concentrations in certain high-level waste repository environments may be limited by Pd metal and may be less than 10-9M.

Micellar catalysis of organic reactions. VIII. Kinetic studies of the hydrolysis of 2-acetyloxybenzoic acid (aspirin) in the presence of micelles

1982 ◽  
Vol 35 (7) ◽  
pp. 1357 ◽  
Author(s):  
TJ Broxton
Keyword(s):  
Aqueous Solution ◽  
Cetyltrimethylammonium Bromide ◽  
Cetylpyridinium Chloride ◽  
Kinetic Studies ◽  
Base Catalysis ◽  
Plateau Region ◽  
General Base ◽  
Mechanism Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of 2-acetyloxybenzoic acid in the pH range 6-12 has been studied in the presence of micelles of cetyltrimethylammonium bromide (ctab) and cetylpyridinium chloride (cpc). In the plateau region (pH 6-8) the hydrolysis is inhibited by the presence of micelles, while in the region where the normal BAC2 hydrolysis (pH > 9) occurs the reaction is catalysed by micelles of ctab and cpc. The mechanism of hydrolysis in the plateau region is shown to involve general base catalysis by the adjacent ionized carboxy group both in the presence and absence of micelles. This reaction is inhibited in the presence of micelles because the substrate molecules are solubilized into the micelle and water is less available in this environment than in normal aqueous solution.

scholarly journals An Investigation into the Adsorption of Aniline from Aqueous Solution Using H-Beta Zeolites and Copper-Exchanged Beta Zeolites

2005 ◽  
Vol 23 (3) ◽  
pp. 255-266 ◽  
Author(s):  
J. O'Brien ◽  
T. Curtin ◽  
T.F. O'Dwyer
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Zeolite Beta ◽  
Langmuir Model ◽  
Beta Zeolite ◽  
Copper Leaching ◽  
Beta Zeolites ◽  
The Stability ◽  
Ph Range ◽  
Adsorbent Materials

Zeolite beta, a large-pore zeolite, was investigated in this study with a view to examining it as a potential adsorbent for the removal of aniline from aqueous solutions. Two different metal-loaded zeolites were prepared by exchanging H-beta zeolite (SiO2/Al2O3 = 75:1) with copper. The influence of exchanged copper on the uptake level was assessed. The effect of varying the silica-to-alumina ratio of the H-beta zeolite on the aniline uptake level was also examined, using three different H-beta zeolites with ratios of 25:1, 75:1 and 150:1 as adsorbents. The sorption experiments indicated an uptake level of ca. 110–120 mg/g for each zeolite and this level was also adsorbed by the copper-modified H-beta zeolites (SiO2/Al2O3 = 75:1). In all cases, the adsorption process followed the Langmuir model for adsorption and the level of aniline adsorbed was largely unaffected by a change in temperature or the presence of extra framework copper. The stability of the exchanged copper on these zeolites was then examined by measuring the quantity of copper leached from each zeolite into solution as a function of pH. Minimum copper leaching was observed in the pH range 5–11. This provided a stable pH working range for the adsorbent materials.

Preparation and Microanalysis Study of Nano-Hap/Cs-Chs Composites Materials

2012 ◽  
Vol 581-582 ◽  
pp. 463-466 ◽  
Author(s):  
Man De Qiu ◽  
Xiao Yan Wang ◽  
Yong Qing Zhai ◽  
Zi Hua Yao
Keyword(s):  
Chondroitin Sulfate ◽  
Organic Phase ◽  
Nano Particles ◽  
Precipitation Method ◽  
Composites Materials ◽  
Before And After ◽  
Calcium And Phosphorus ◽  
Co Precipitation

Nano-hydroxyapatite/chitosan-chondroitin sulfate composites materials with different weight ratios were prepared through liquid co-precipitation method. The nano-Hap、Hap/Cs and Hap/Cs-Chs composites materials under the same conditions preparation materials were researched By XRD, SEM and EDS respectively. The results show that nano-Hap particles with poorly crystallinity, the size is about 20nm, nano-Hap particles are spherical in sHape and dispersed uniformly, combined with relatively loose between particles, the small nano-particles aggregate into larger particles when the Hap composite with the Cs and Chs, nano-Hap were dispersed uniformly in the organic phase Cs and Chs, Hap particles have the trend to grow large in composites materials,crystal become more perfect, combination become relatively dense between particles, The composites materials were annealed at 700°C,Hap crystal particles become more perfect clear and larger with relatively loose between particles.EDS analysis showed that the compound before and after annealing of the material ratio of calcium had no influence, material does not contain any impurities,The ratio of calcium and phosphorus is about 1.75:1,Hap belonging to the type of calcium-rich

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