Journal of Applied Chemical Research
Volume:7 Issue: 3, Summer 2013

The color developing reaction between ambrisentan and 2,3-dichloro-5,6-dicyano-1,4- benzoquinone (DDQ) or 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (CLA) was successfully employed in the development of two simple and sensitive spectrophotometric methods (M1 and M2) for the determination of ambrisentan in its pharmaceutical dosage forms.The methods are based on the charge transfer reaction of ambrisentan with DDQ (M1) or CLA (M2), to give colored radical anions. The colored products are measured at 560 nmin methanol and at 520 nm in acetonitrile for the methods M1 and M2, respectively.Under the optimized reaction conditions, Beer’s law is obeyed in the range of 5–50 μg ml−1 for both the methods. The limit of detection, limit of quantification, molar absorptivity and Sandell’s sensitivity were also reported for both the methods. Intra- and inter-day precision and accuracy of the methods were satisfactory. The proposed method was successfully applied to the quantification of ambrisentan in its tablet dosage forms with good accuracy and precision.

The magnetic properties of calcined cobalt ferrite formed by nano-crystalline powders have been compared by two different methods (co-precipitation and hydrothermal). The structural properties of the produced powders were investigated by X-ray Diffraction (XRD), scanning electron microscopy (SEM). The results show that the formation of cobalt ferrite spinel structures is effected by changing methods. Both techniques were effective and led to the production of spinel phase and crystalline nano-powders. Magnetic hysteresis was measured by using a vibrating sample magnetometer (VSM) in a maximum field of 10 kOe. The saturation magnetization (Ms), remanence (Mr) and coercivity (Hc) were derived from the hysteresis loops. The results revealed that the magnetic properties of nano-particles depend on the structure, composition and size of particle.

A spectrophotometric study concerning the interaction between Trimethoprim (TMP) ,Sulfamethoxazole (SFMx), as n-donor and 2,3-dichloro-5,6- dicyano-P-benzoquinine (DDQ) and chloranilic acid (CA) as π-acceptor were been performed at 25°C. The results of interaction of CA and DDQwith TMP indicate the formation of a 1:1, 1:2, charge transfer complexes through non equilibrium reactions. In the case of SFMx, the formation of 1:2 (SFMx/DDQ, SFMx /CA) charge-transfer complexes is confirmed. The formation constantsof the equilibrium step were evaluated from the computer fitting of the absorbance-mole ratio data. Also, this study was carried out to simultaneously determine quantitatively TMP in Cotrimoxazole. The complexes of TMP with DDQ and chloranilic acid absorbed maximally in 512 and 585, respectively.

Many strategies have been developed to improve vaccine delivery in the past decade. The aim of the current study was to develop a nanoparticulate system based on ionic gelation between chitosan and tripolyphosphate in order to load Androctonus Crassicauda scorpion venom. The best formulation was selected according to the highest association efficiency, loading capacity, optimum particle size and zeta potential. Venom release studies were carried out on the optimum formulation F3. The highest association efficiency (77%) and loading capacity (48%) were obtained from formulation containing chitosan (2.0mg/ml), TPP ( mg/ ml) and scorpion venom concentration of 250μg/ml. The average size of nanoparticles in optimum formulation was about 230 nm with a polydispersity index of 0.479 and a positive zeta potential value. The FTIR results also confirmed the binding of TPP and chitosan with the venom peak present in the nanoparticle formulation. The in vivo release of venom from nanoparticles at pH 7.2 showed an initial burst release of about 69% in the first 24 hours followed by a sustained and much slower release in the next 96 hours. The result suggested that this nanoparticulate system maybe suitable as an antigen carrier with anti- venom activity for further in vivo studies.

Polyaniline-cobalt nanocomposites were synthesized bysalt of cobalt with ammonium persulphate as an oxidizing agent and aniline.This paper reports on hydrothermal technique using for synthesis and size control of cobalt nanoparticles in the composite bridge is aniline. Electrical conductivity of polyaniline alone in acidic environments, without and with cobalt nanoparticles measured.Increasing amounts of cobalt nanoparticles in the sample equivalent to the highest electrical conductivity. We also studied morphology of polyanilinecobalt nanocomposite. Sizeofcobalt particles were conformed~33 nm in the structure of nanocomposite.

The present work investigates an appropriate way to calculate the 1700 atomic density changes in the reactor operations. To automate this procedure, a computer program has been designed by C#. This program suggests a way to solve this problem which is based on the solution system of differential equations (Bitman) that it is designed according to Runge Kutta Fehlberg method. The designed software is based on the high ability to calculate the material depletion with constant flux and constant power condition. The software inputs included, reactor power, computation time, initial and final time, determine of Taylor series order in calculation time depended flux, determination of time unite, specifyingmaterial composition of the reactor core at initial condition consist of light radioactive material, heavy and fission products, determining the order in the accuracy of calculations, applying the decay constants library, cross section database, the amount of generated thermal energy by various material decay ,determining the type of calculations at point of view constant flux or constant power. Finally, the atomic density of light, heavy materials and fission products at various times of reactor operation were calculated with high accuracy as the out puts of this program. At last, it is worth to say that we proposed a new approach for the use the Runge-Kutta Fehlberg method to compute atomic density changes of material composition of the reactor core which lead us to achievement a high ability tool to solve the above problem.

Ultrasonic technology and response surface methodology (RSM) wereused for optimization of extraction of condensed tannins from the leaf, acron, gland and gall of oak. Three independent variables such as solvent percentage (%), temperature (°C) and time (min) were studied. Effect of methanol concentration was found to be significant on all responses. Optimal ultrasonicassisted extraction (UAE) conditions were identified as 74–82% methanol, 60°C and45 min.The experimental values agreed with those predicted by RSM models, thus indicating suitability of the models employed and the success of RSM in optimizing the extraction conditions. Condensed tannins can be used as wood adhesives.

The present investigation assesses the application of ceric sulfate for the removal of the colorant reactive blue19 (R.B19) from synthetic wastewater. The adsorption characteristics and dye removal efficiency of adsorbent have been determined by investigating factors such as effect of pH (pHOptimum