Mansing A. Anuse

Liquid–liquid extraction of palladium(II) with N-n-octylaniline from hydrochloric acid media

N-n-Octylaniline in xylene is used for the extractive separation of palladium(II) from hydrochloric acid medium. Palladium(II) was extracted quantitatively with 10 ml of 2% reagent in xylene from 0.5-2 M hydrochloric acid medium. It was stripped from the organic phase with 1:1 ammonia and estimated spectrophotometrically with pyrimidine-2-thiol at 420 nm. The effects of metal ion, acids, reagent concentration and of various foreign ions have been investigated. The method affords binary separation of palladium(II) from iron(III), cobalt(II), nickel(II) and copper(II) and is applicable to the analysis of synthetic mixtures and alloys. The method is fast, accurate and precise.

Extraction and separation studies of platinum(IV) with N-n-octylaniline

N-n-octylaniline in xylene is used for the extractive separation of platinum(IV) from acidic media. Platinum(IV) was extracted quantitatively with 10 ml of 3% reagent in xylene from 0.5 to 10 and 2.5 to 10 M hydrochloric and sulphuric acid, respectively. It was stripped from organic phase with water and estimated photometrically with stannous chloride. The effect of metal ion, acids, reagent concentration and of various foreign ions has been investigated. The method affords binary separation of platinum(IV) from iron(III), cobalt(II), nickel(II) and copper(II), and is applicable to the analysis of synthetic mixtures and alloys. The method is fast, accurate and precise.

Dissipation and distribution behavior of azoxystrobin, carbendazim, and difenoconazole in pomegranate fruits.

The dissipation behavior and degradation kinetics of azoxystrobin, carbendazim, and difenoconazole in pomegranate are reported. Twenty fruits/hectare (5 kg) were collected at random, ensuring sample-to-sample relative standard deviation (RSD) within 20-25%. Each fruit was cut into eight equal portions, and two diagonal pieces per fruit were drawn and combined to constitute the laboratory sample, resulting in RSDs <6% (n = 6). Crushed sample (15 g) was extracted with 10 mL of ethyl acetate (+ 10 g Na(2)SO(4)), cleaned by dispersive solid phase extraction on primary secondary amine (25 mg) and C(18) (25 mg), and measured by liquid chromatography tandem mass spectrometry. The limit of quantification was ≤0.0025 μg g(-1) for all the three fungicides, with calibration linearity in the concentration range of 0.001-0.025 μg mL(-1) (r(2) ≥ 0.999). The recoveries of each chemical were 75-110% at 0.0025, 0.005, and 0.010 μg g(-1) with intralaboratory Horwitz ratio <0.32 at 0.0025 μg g(-1). Variable matrix effects were recorded in different fruit parts viz rind, albedo, membrane, and arils, which could be correlated to their biochemical constituents as evidenced from accurate mass measurements on a Q-ToF LC-MS. The residues of carbendazim and difenoconazole were confined within the outer rind of pomegranate; however, azoxystrobin penetrated into the inner fruit parts. The dissipation of azoxystrobin, carbendazim, and difenoconazole followed first + first order kinetics at both standard and double doses, with preharvest intervals being 9, 60, and 26 days at standard dose. At double dose, the preharvest intervals extended to 20.5, 100, and 60 days, respectively.

Extraction of Ruthenium(IV) from Hydrochloric Acid Medium with N-Octylaniline and Its Determination Spectrophotometrically with Pyrimidine-2-thiol

A novel method is proposed for the extraction of microgram level concentrations of ruthenium(IV) from halide medium with N-octylaniline dissolved in xylene as an extractant. The optimum conditions have been determined by making a critical study of acid concentration, extractant concentration, period of equilibration, and effect of solvent on the equilibria. The ruthenium(IV) from the organic phase is stripped with sodium chloride solution and determined spectrophotometrically with pyrimidine-2-thiol as a reagent. The method affords the binary separation of ruthenium(IV) from base metals such as iron(III), cobalt(II), nickel(II), and copper(II), and it is used for analysis of synthetic mixtures of associated metal ions and alloys. It can be successfully applied for the separation and determination of ruthenium(IV) from the constituent elements of a fuel used for Experimental Breeder Reactor II. The method is highly selective, simple, and reproducible.

Removal of Bi (III) with Adsorption Technique Using Coconut Shell Activated Carbon

Abstract In present study, we report the preparation of coconut shell activated carbon as adsorbent and its application for Bi (III) removal from aqueous solutions. The developed adsorbent was characterized with scanning electron microscope (SEM), Fourier Transform Infrared (FTIR), C, H, N, S analyzer, and BET surface area analyzer. The parameters examined include agitation time, initial concentration of Bi (III), adsorbent dose and temperature. The maximum adsorption of Bi (III) (98.72%) was observed at 250 mg·L−1 of Bi (III) and adsorbent dose of 0.7 g when agitation was at 160 r·min−1 for 240 min at (299±2) K. The thermodynamic parameters such as Gibbs free energy (ΔGθ), enthalpy (ΔHθ) and entropy (ΔSθ) were evaluated. For the isotherm models applied to adsorption study, the Langmuir isotherm model fits better than the Freundlich isotherm. The maximum adsorption capacity from the Langmuir isotherm was 54.35 mg·g−1 of Bi (III). The kinetic study of the adsorption shows that the pseudo second order model is more appropriate than the pseudo first order model. The result shows that, coconut shell activated carbon is an effective adsorbent to remove Bi (III) from aqueous solutions with good adsorption capacity.

Extraction, Separation and Spectrophotometric Determination of Bismuth(III) Using 1(4′-Bromophenyl) 4,4,6-Trimethyl (1H,4H)-Pyrimidine-2-Thiol

Abstract The operating conditions for the spectrophotometric determination of bismuth(III) with 1-(4′-bromophenyl)-4,4,6-trimethyl-(1H,4H)-pyrimidine-2-thiol (4′bromo PTPT) as a ligand by a liquid-liquid extraction technique are presented. In acidic conditions bismuth(III) forms a yellow complex with the ligand which can be extracted in chloroform with an absorption maxima at 410 nm. The molar absorptivity is 1.5×104 l mole−1 cm−1 and Sandells sensitivity is 14.3 ng cm−2. The difference in the absorbance between the chloroform blank and bismuth(III) sample increases linearly in the concentration range 2-14 ppm at 0.3 M hydrochloric acid. The proposed method is extremely sensitive, rapid, reproducible and has been satisfactorily applied to the determination of trace amounts of bismuth(III) in synthetic mixtures, alloys and pharmaceutical formulations and also provides binary separation of bismuth(III) from selenium, tellurium, lead, antimony, copper and gold. The overall process of extraction and determin...

Rapid extraction of lead(II) from succinate media with n-octylaniline in toluene

Abstract The distribution equilibrium of lead(II) species between aqueous succinate media and n-octylaniline was studied as a function of the concentrations of extractant in organic phase, weak organic acid concentration, different diluents and effect of shaking period on extraction. The quantitative extraction of lead(II) was observed with n-octylaniline in toluene from 0.0035 to 0.0065 M sodium succinate media in the pH range 8.0–8.3. The metal ion was stripped out from organic phase with water and determined complexometrically with disodium salt of EDTA or spectrophotometrically with PAR. The extraction of lead(II) was quantitative in most aromatic solvents, such as benzene, toluene and xylene, and oxygen containing solvents, amyl alcohol and n-butanol, and also in carbon tetrachloride. The stoichiometry of the extracted species was determined on the basis of slope analysis and found to be 1:2:2 (metal: acid: extractant). As an application the system was used for selective extraction of lead(II) from its binary mixture with Zn(II), Tl(I), Tl(III), Bi(III), Al(III), Cu(II), Th(IV), U(VI), Sn(IV), Sb(III) and Ca(II). The distribution coefficient for lead(II) in succinate media was of higher magnitude than salicylate and malonate media. This developed method was successfully applied for the analysis of lead(II) in real samples such as alloys, ores and pharmaceutical materials.

Rapid Solvent Extraction of Gold(III) with High Molecular Weight Amine from Organic Acid Solution

A novel solvent extraction separation method has been developed for the determination of gold in real samples. It involves selective and quantitative extraction of gold by N-n-octylaniline, a high molecular weight amine (HMWA), in xylene from aqueous sodium malonate medium at pH 1.0. The effects of concentration of malonate, extractant, metal ion, and pH and of various diluents, stripping agents and other substances on the quantitative extraction of gold have been assessed. The applicability of the method to binary mixtures, synthetic mixtures, alloys and pharmaceutical samples is discussed.

Solvent extraction separation of rhodium(III) with N-n-octylaniline as an extractant.

Solvent extraction separation method for the determination of rhodium(III) has been described. Selective and quantitative extraction of rhodium(III) by N-n-octylaniline, a high molecular weight amine (HMWA) into xylene takes place from aqueous sodium malonate medium. The effect of concentration of malonate, N-n-octylaniline, role of various diluents, stripping agents and foreign ions on the extraction of rhodium(III) has been studied. The procedure offers distinct improvements in need of real sample analysis and environmental safety as the extraction procedure carried out in weak organic acid media.

SEPARATION OF MOLYBDENUM(VI) BY EXTRACTION WITH N-OCTYLANILINE FROM HYDROCHLORIC ACID MEDIUM

Abstractn-Octylaniline in bezene was used for the extractive separation of molybdenum (VI) from hydrochloric acid medium. Molybdenum(VI) was extracted quantitatively from 10 ml aqueous solution 1.5M in hydrochloric acid and 10M in lithium chloride into 10 ml of 10%n-octylaninline in benzene. It was stripped from the organic phase with 5% aqueous ammonia solution and estimated spectrophotometrically with thiocyanate at 465 nm. The interference of various ions has been studied in detail and conditions have been established for the determination of molybdenum(VI) in synthetic mixtures and alloy samples.