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

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 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

Efecto del abonado orgánico y biológico sobre el rendimiento de los frutos y los aceites esenciales del hinojo (Foeniculum vulgare var. dulce)

In order to evaluate the effects of different organic and biological fertilizers on quantity and quality of fennel essentialoil, an experiment was conducted in a completely randomized block design with three replications. The experimentaltreatments included two organic (compost and vermicompost) and two biological (Pseudomonas putida and Azotobacterchroococcum) fertilizers, their all twin combinations (Ps. putida + A. chroococcum, Ps. putida + compost, Ps. putida + vermicompost, A. chroococcum + compost, A. chroococcum + vermicompost and compost + vermicompost) and control (non fertilized). There were significant differences between treatments in terms of seed essential oil percentage, essential oil yield; anethole, fenchone, limonene and stragole content in seed essential oil. Results showed that the highest and the lowest percentages of essential oil were obtained in control (2.9%) and A. chroococcum + vermicompost (2.2%) treatments, respectively. The highest essential oil yield (29.9 L ha–1) and anethole content of essential oil (69.7%) and the lowest contents of fenchone (6.14%), limonene (4.84%) and estragole (2.78%) in essential oil were obtained in compost + vermicompost treatment. It seems that compost + vermicompost treatment compared to other treatments supplied the highest equilibrium of nutrients and water in the root zone of sweet fennel which is led to increasing the anethole content, there upon, decreasing other compounds. Essential oil yield and percentage of anethole content in essential oil were significantly higher in all organic and biological treatments compared with control.Con el fin de evaluar los efectos de diferentes fertilizantes orgánicos y biológicos sobre la cantidad y calidad del aceite esencial de hinojo, se realizó un experimento en un diseño aleatorizado de bloques completos con tres repeticiones. Los tratamientos experimentales incluyeron todas las combinaciones dobles de dos fertilizantes orgánicos ydos biológicos (Pseudomonas putida + Azotobacter chroococcum, Ps. putida + compost, Ps. putida + humus de lombriz, A. chroococcum + compost, A. chroococcum + humus de lombriz, y compost + humus de lombriz) y un control(sin fertilizar). Hubo diferencias significativas entre tratamientos en términos de porcentaje del aceite esencial de las semillas, rendimiento de aceite esencial y contenido en anetol, fenchone, limoneno y estragol en el aceite esencial.Los resultados mostraron que el mayor y el menor porcentaje de aceites esenciales se obtuvieron en los tratamientos control (2,9%) y A. chroococcum + humus de lombriz (2,2%), respectivamente. En el tratamiento compost + humus de lombriz se obtuvo la mayor producción de aceite esencial (29,9 L ha–1) y contenido en anetol (69,7%), así como elmenor contenido de fenchone (6,14%), limoneno (4,84%) y estragol (2,78%). Parece que el tratamiento de compost + humus de lombriz suministró el mayor equilibrio de nutrientes y agua en la zona de la raíz del hinojo en comparación con otros tratamientos, lo que aumenta el contenido de anetol, y por tanto disminuye el de otros compuestos. La producción de aceite esencial y el porcentaje de contenido en anetol en el aceite esencial fue significativamente mayor en todos los tratamientos orgánicos y biológicos que en el control

Study of Complex Formation Between Iodoquinol (IQ) and Co2+ , Mn2+, Cd2+, Pb2+ and Zn2+ Cations in Binary Aqueous / Non-aqueous Solvent Using Spectrophotometry

The complexation reactions between iodoquinol and Co2+, Mn2+, Cd2+, Pb2+ and Zn2+ cations were studied in different DMF/H2O binary mixtures at the ionic strength of 0.1(using NaNO3).The spectrophotometric method was used for the determination of formation constants and the stoichiometries. The stoichiometry of the complexes is established 1:1 by Job's and mole ratio methods. It was found that the stability constants of the complex formed between the ligand (IQ) and the cations in the all cases increase with increasing of the non-aqueous solvent. In the most cases the maximum formation constants between Zn2+ ion and IQ were obtained respect to the other cations

Competitive Bulk Liquid Membrane Transport and Extraction of Cu(II), Ni(II), Zn(II) and Mn(II) Cations Using 5-Methyle-4[thiophen-2-yl-methylen-amino]-3-thio-oxo-1, 2, 4-triazol-5-one and Phthalic Dicarboxaldehyde

The competitive metal ion extraction and transport of Cu(II), Ni(II), Zn(II) and Mn(II) with a S-N donor, i.e. 5-methyle-4[thiophen-2-yl-methylen-amino]-3-thio-oxo-1,2,4-triazol-5-one(ATTT) and oxygen donor, phthalic dicarboxaldehyde(PHDC) compounds was examined and compared each other. Although the extraction and transport behavior of Cu(II) and Zn(II) with both ATTT and PHDC ligands is fundamentally similar, but the transport efficiency for Cu(II) is much better than Zn(II) ion. The transport and extraction results closely parallel for the cations using the present ligands. The experiments were buffered (acetic acid/sodiumacetate and formic acid/sodiumformate) at pH 3-7. The concentrations in the all transport and extraction experiments for the cations and ligands were 0.01 M and 1.0 x10-3 M respectivel

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Modeling and optimal control of a wheel loader in the lift-transport section of th

Selective Extraction and Bulk Liquid Membrane Transport of Cu(II) from Aqueous Nitrate Solution in the Presence of Zn(II), Ni(II) and Mn(II) Cations Using Benzoyl Acetone

The competitive metal ion extraction and transport of Cu(II), Ni(II), Zn(II) and Mn(II) with benzoyl acetone and EDTA was studied. In the experiments the ligand was dissolved in chloroform and the pH and time of extraction or transport were varied. Also the rate of shaking and ligand concentration on the efficiency of extraction and transport was studied. The results revealed that the ligands exclusively extract Cu(II) from the mixture of the above cations