64 research outputs found
Graphite furnace atomic absorption spectrometric determination of cadmium after solid-liquid extraction with dithizone
A method for the determination of trace amount of cadmium ion after preconcentration by extracting its dithizone complex into molten naphthalene was developed. Several experimental conditions such as pH of the solution, stirring time, the amounts of naphthalene, standing time and volume of the solution were optimized. Trace amount of cadmium ion in aqueous solution of sample was chelated with 5 mL of 0.001 M dithizone at pH 8. After addition of 0.15 g naphthalene, the solution was heated to about 85 oC and stirred (800rpm) for 2 min to reproduce the microcrystalline naphthalene. Cadmium ion was determined by a graphite furnace atomic absorption spectrometer. The interfering effects of diverse concomitant ions (cations and anions) wereinvestigated. Artificial sea water and a standard reference material (SRM) were analyzed by this method. The sensitivity and detection limit of 1.2 ngL-1 and 1.5 ng L-1 were found, respectively
Chemical Composition of the Essential Oil From the Aerial Parts of<i>Artemisia Herba</i>
The aerial parts of the plant artemisia herba were collected in the May 2007 from Babaaman (North Khorassan Province of Iran). The plant was isolated by hydro distillation. A total of 61 constituents, representing more than 98% of the oil were identified by gas chromatograph/mass spectrometry (GC/MS). The main compounds, were alpha-pinene (3.28%), champhene (4.8%), sabinen (5.18%), beta-myrcene (3.04), cis,beta-terpineol (11.31%), camphor (6.11%), 8-hydroxylinalool (2.64%), L-4-terpineol ( 2.5%), alpha- therpineol (2.33%), myrtenol (3.27%), bornyl acetate (6.2%), alpha-terpinol acetate (3.06%), germacrene (2.06%), davanone (8.49%), trans-farnesol (4.27%), cis-fernesol (2.07%) and 1,3,dicyclopentyl cyclopentane (2.29%). This herbal medicine traditionally uses as anti-infectious, anti-bacterial, emmenagogue, parasiticide, digestive and stomachic and gastric tonic in Iran.</jats:p
Selective transport of Ag (I) ion across a bulk liquid and polymer membranes incorporated with di-N-benzylated O3N2 donor macrocycles
Thermodynamic study of complex formation between 3,5-di iodo-hydroxy quinoline and Zn2+, Ni2+ and Co2+ cations in some binary solvents using a conductometric method
AbstractThe complexation reactions between 3,5-di iodo-8-hydroxy quinoline (IQN) and Zn2+, Ni2+ and Co2+ were studied in dimethylformamide (DMF)-ethanol (EtOH) binary solvent systems at different temperatures using a conductometric method. The stoichiometry of complexes was established 1:1. It was found that the stability of complexes formed between cations and this ligand increases with increases temperature. The standard enthalpies and standard entropies of complexes were obtained from the temperature dependence of stability constants. The results obtained by conductometric technique show that there is an inverse relationship between the formation constants of complexes and donor number of solvents. In all cases, the formation constants increased with increasing amounts of EtOH versus DMF in these binary systems. The standard enthalpy and standard entropies of complexes were obtained from the temperature dependence of stability constant. In all cases, ΔH° was positive and ΔS° was negative. The selectivity order for IQN complexes among various neat studied solvents varies in the order: Zn–IQN2+› Ni–IQN2+›Co–IQN2+
Competitive bulk liquid membrane transport of Co(II), Ni(II), Zn(II), Cd(II), Ag(I), Cu(II) and Mn(II), cations using 2,2′-dithio(bis)benzothiazole as carrier
Selective Transport of Silver(I) Ion Through Polymer Membranes Containing Thioether Donor Macrocycles as Carriers
The Preparation of polymer membrane and it's selectivity to silver(I) ion from an aqueous solution containing seven metal cations, Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II), was studied. The source phase contained equimolar concentrations of the above mentioned cations with the source and receiving phases being buffered at pH 5.0 and 3.0 respectively. The effect of variation in the number of the macrocyclic sulfur atom donor set anssd the size of ring 9 and 16 member macrocycles on transport efficiency is presented. Silver(I) ion transport occurred (at 25°C) from the aqueous source phase across the polymer membrane (derived from cellulos triacetate) containing ligands 9-membered, S3-donor and16-membered S4-donor macrocycles as the ionophors in separate experiments into the aqueous receiving phase. Clear transport selectivity for silver(I) ion was observed using both thioether donor macrocycles. The efficiency of transport rate for silver(I) ion with using 9-membered S3-donor macrocycle as carrier was better than 16-membered S4-donor
Thermodynamic study of complex formation between 3,5-di iodo-hydroxy quinoline and Zn2+, Ni2+ and Co2+ cations in some binary solvents using a conductometric method
The complexation reactions between 3,5-di iodo-8-hydroxy quinoline (IQN) and Zn2+, Ni2+ and Co2+ were studied in dimethylformamide (DMF)-ethanol (EtOH) binary solvent systems at different temperatures using a conductometric method. The stoichiometry of complexes was established 1:1. It was found that the stability of complexes formed between cations and this ligand increases with increases temperature. The standard enthalpies and standard entropies of complexes were obtained from the temperature dependence of stability constants. The results obtained by conductometric technique show that there is an inverse relationship between the formation constants of complexes and donor number of solvents. In all cases, the formation constants increased with increasing amounts of EtOH versus DMF in these binary systems. The standard enthalpy and standard entropies of complexes were obtained from the temperature dependence of stability constant. In all cases, ΔH° was positive and ΔS° was negative. The selectivity order for IQN complexes among various neat studied solvents varies in the order: Zn–IQN2+› Ni–IQN2+›Co–IQN2+
Selective oxidation of primary substituted aromatic amines to azoxy products using lacunary catalyses
Selective Transport of Silver(I) Ion Through Polymer Membranes Containing Thioether Donor Macrocycles as Carriers
The Preparation of polymer membrane and it's selectivity to silver(I) ion from an aqueous solution containing seven metal cations, Co(II), Ni(II), Cu(II), Zn(II), Ag(I), Cd(II) and Pb(II), was studied. The source phase contained equimolar concentrations of the above mentioned cations with the source and receiving phases being buffered at pH 5.0 and 3.0 respectively. The effect of variation in the number of the macrocyclic sulfur atom donor set anssd the size of ring 9 and 16 member macrocycles on transport efficiency is presented. Silver(I) ion transport occurred (at 25°C) from the aqueous source phase across the polymer membrane (derived from cellulos triacetate) containing ligands 9-membered, S3-donor and16-membered S4-donor macrocycles as the ionophors in separate experiments into the aqueous receiving phase. Clear transport selectivity for silver(I) ion was observed using both thioether donor macrocycles. The efficiency of transport rate for silver(I) ion with using 9-membered S3-donor macrocycle as carrier was better than 16-membered S4-donor
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