Open Access Original Research Article

Thermochemistry of Heteroatomic Compounds: Analysis and Calculation of Some Thermodynamic Functions of Saturated Alkanes

Vitaly Ovchinnikov

Chemical Science International Journal, Page 1-13
DOI: 10.9734/ACSJ/2014/4844

The correlation equation Dc,f,vapΨo = i + f *N have been used for the description of thermodynamic functions DΨo of free energy, heat, entropy and heat capacity of the combustion, formation and vaporization processes for alkanes of the different space structure. The i and f are stoichiometric coefficients; they have been determined for 34 equations, which have described the processes in condensed and gaseous phases. The consideration of all presented data allows to draw the main essential conclusion: the all mentioned above functions depend on number of valence electrons in the researched substances.The heat capacities depend on number of valence electrons too.

 

Open Access Original Research Article

Prediction of Retention in Gradient Reversed-Phase Liquid Chromatography for Phenyl Isothiocyanate-Derivatives of Amino Acids

Jelena Golushko, Svetlana Vorslova, Sergey Galushko, Arturs Viksna, Kristine Edolfa

Chemical Science International Journal, Page 14-23
DOI: 10.9734/ACSJ/2014/6299

Aim: To study the applicability of the solvatic retention model for the prediction of retention times in gradient elution of phenylisothiocyanate derivatives of natural amino acids.

Methodology: The solvatic retention model of reversed-phase liquid chromatography has been used to predict retention of phenylisothiocyanate derivatives of 25 natural amino acids under conditions of gradient elution. Retention factors have been calculated from molecular parameters of the structures of analytes and the characteristics of a column and an eluent using the ChromSword software package.

Results: The modeled initial estimation of retention time was found to be within 4% of the experimentally determined retention time. Fine-tuning of the model parameters using data from experimental runs further improved the accuracy of the model.

Conclusion: A step-by-step method which includes the first-guess prediction of initial conditions from structural formula and fine tuning parameters of the retention model using data from successive runs can save time in method development and optimization of the separation of target compounds.

 

Open Access Original Research Article

FT-Raman Spectroscopy and PLS Regression for Quantitative Determination of Captopril in Tablet Powder; Effect of Different Preprocessing Methods

Ahmed Shawky, Ahmed Ibrahim, Maissa Y. Salem, Ahmed E. El Gindy

Chemical Science International Journal, Page 24-37
DOI: 10.9734/ACSJ/2014/6087

Aims: This study was performed to develop a fast and simple method for the quantitative analysis of Captopril in tablet powder by FT-Raman Spectroscopy and PLS regression. The effect of different preprocessing methods on multivariate calibration was studied.

Methodology: Four different preprocessing methods, namely mean center (MC), autoscale (AS), normalization (N1) and orthogonal signal correction (OSC) were applied to reduce the impact of sources of variability, such as instrument drift and sampling variability, correct for path length variation and increase the signal to noise ratio. PLS regression models were fitted and their predictive performance was evaluated by the root mean square error of prediction (RMSEP) and number of latent variables (LVs).

Place and Duration of Study: School of Pharmacy, University of Maryland, between July to November 2012.

Results: N1-AS combination (in this order) was found to give best results as it decreased the RMSEP by 15 % (from 0.92 to 0.77) with  same number of latent variable used in the model (2 LVs). Other preprocessing methods have not yielded good results for this application. The results obtained by the proposed method were compared with those of the reported HPLC method. No significant difference has been observed regarding both accuracy and precision.

Conclusion: FT-Raman Spectroscopy with PLS regression can be used as a reliable alternative for HPLC method, as it is faster and does not require sample pretreatment procedures.

 

Open Access Original Research Article

Kinetics of the Adsorption of Anionic and Cationic Dyes in Aqueous Solution by Low-Cost Activated Carbons Prepared from Sea Cake and Cotton Cake

Tchakala Ibrahim, Bawa L. Moctar, Kodom Tomkouani, Djaneye- Boundjou Gbandi, Doni K. Victor, Nambo Phinthè

Chemical Science International Journal, Page 38-57
DOI: 10.9734/ACSJ/2014/5403

Activated carbons prepared from shea cake (CA-K) and cotton cake (CA-C) were investigated for removal of four dyes in aqueous solutions (0 – 200 mg/L): Reactive Black 5 (RB5), Methylene blue (BM), Reactive Orange 16 (RO16) and Methyl Orange (MO) from water by adsorption. The activated carbons were prepared by chemical activation using phosphoric acid as activation agent. Chemical characteristics of these activated carbons was monitored by Bohem titration and the method of Lopez-Ramon et al. while surface areas of the samples were determined by nitrogen adsorption/desorption isotherm measurement. Activated carbons CA-K and CA-C have the following characteristics: BET surface and the pore volumes are respectively 1148 m2/g and 0.607 cm3/g for CA-K, 584 m2/g and 0.298 cm3/g for CA-C. The two activated carbons synthesized are microporous activated carbon with micropores volume representing more than 70% of the total pore volume. The removal of dyes was studied using batch reactor. The nature of the activated carbon and the dyes are the key factors influencing the contact time. At the equilibrium times (35 to 270 min for CA-K and 60 to 300 min for CA-C), the removal of BM, MO and RO16 was quasi-total while for RB5 the amount adsorbed was about 83%. Based on the adsorption capacity, it was shown that CA-K was more effective than CA-C. Various kinetic models such as pseudo first-order, pseudo second-order and intraparticle diffusion were used to evaluate the mechanism of dyes adsorption on activated carbons. BM, RO16, and MO removal process was found to be governed by second-order kinetic while pseudo-first order kinetic is suitable for RB5 adsorption study. The pHs of the solutions and the amount of activated carbon have strong effect on the adsorption capacity of these dyes. An acid pH (for anionic dyes) and basic pH (for cationic dyes) were favorable for the maximum adsorption of dyes. The isotherm data could be well described by the Freundlich and Langmuir equations in the concentration range of 0–80 mg/L. For the present adsorption process intraparticle diffusion of dyes within the particle was identified to be rate limiting. Both activated carbons were shown to be promising materials for adsorption removal of dyes from aqueous solutions.

 

Open Access Original Research Article

6,11-Bisthia Steroidal Analogues: Synthesis, Characterization, and Evaluation of Antimicrobial-, Antituberculosis-, and Antitumor Activity

Sudalaiandi Kumaresan

Chemical Science International Journal, Page 58-73
DOI: 10.9734/ACSJ/2014/6269

Aims: Synthesis, characterization, antimicrobial-, antituberculosis-, and antitumor activity of a few 6,11-bisthiasteroidal analogues have been carried out.

Methodology: Subsequent reaction of the mixture 3 with phenylhydrazine hydrochloride/hydrazine hydrochloride under reflux in ethanol afforded the pyrazole derivatives 4/5. The isoxazole moiety in compounds 6 was built up from 3 with hydroxylamine hydrochloride. The pyrimidine derivatives 7 and 8 were prepared from the diketoester mixture 3 with urea and thiourea respectively. The benzodiazepine derivatives 9 and 10 were prepared from the condensation of 3 with o-phenylenediamine and 1,2-diphenylethane-1,2-diamine, respectively.

Results: Compound 10 showed higher bioactivity against Klebsiella pneumoniae and Escherichia coli than the standard, chloroamphenicol, and equipotent to clotrimazole in inhibiting the growth of Candida albicans. These compounds were screened for their cytotoxic activity against human colon tumor cell line (HCT116) and human cervical cancer cell line (HeLa). Compound 10 displayed the highest activity among the tested compounds with IC50 equal to 12 µM for HeLa cell, and 11 µM for HCT116 cell, respectively.  Again, compound 10 was found to be the most promising being active against M. tuberculosis (H37Rv) with MIC 7.5 µM.

Conclusion: Compound 10 displayed better antimicrobial-, antituberculosis-, and antitumor activity than the other derivatives.

 

Open Access Original Research Article

Effects of Aqueous Extract of Ocimum gratissimum on Some Haematological Parameters of Albino Rats

O. A. Ojo, O. I. Oloyede, B. O. Ajiboye, O. I. Olarewaju

Chemical Science International Journal, Page 74-81
DOI: 10.9734/ACSJ/2014/5046

Aims: To evaluate the effects of aqueous extracts of Ocimum gratissimum leaves on the haematological responses of albino rats.

Study Design: Packed cell volume, hemoglobin level, white blood cells and differential cell counts such as neutrophils, lymphocytes, monocytes and eosinophils.

Place and Duration of Study: Department of Chemical sciences, (Biochemistry laboratory), Afe Babalola University and Department of Biochemistry, Ekiti State University, Ado Ekiti, Nigeria between February 2013 and march 2013.

Methodology: Sixteen albino rats with weight ranging between 100-190g were used. The rats were divided into four groups A, B, C and D; with group D as the control group. Increasing doses (100, 200 and 400mg kg-1 body weight) of the extract were administered orally to the other three treatment group A, B and C for a period of two weeks. Standard chemical procedures were used to analyze for packed cell volume, hemoglobin level, white blood cells and differential cell counts such as neutrophils, lymphocytes, monocytes and eosinophils.

Results: The results show a significantly decrease in the hemoglobin level, packed cell volume, white blood cells, neutrophils and lymphocytes respectively. Significant (P = .05) decreases in the level of hemoglobin (Hb) and packed cell volume were observed, whereas no significant (P > .05) differences were observed in percent neutrophils, lymphocyte and monocyte counts of the Ocimum gratissimum treated animals.

Conclusion: The result suggests that Ocimum gratissimum leaf extracts administered at the dosages used and for the duration of the experiment suppress the haemopoetic system of albino rats.

 

Open Access Original Research Article

Synthesis of Petroleum Polymer Resin by Catalytic Polymerization of Pyrocondensate and Its Fractions

H. J. Ibragimov, K. M. Gasimova, Z. M. Ibragimova, G. F. Gasimova

Chemical Science International Journal, Page 82-96
DOI: 10.9734/ACSJ/2014/6320

Aims: The main aim of the present paper is the application of bimetallic complexes synthesized based on aluminium, 1.2-dichloroethane and transition metals in the refining of pyrocondensate.

Place and Duration of Study: Institute of Petrochemical Processes, Azerbaijan National Academy of Sciences, between January 2011 and September 2012.

Methodology: Oligomerization process was carried out in a three-necked flask equipped with mechanical stirrer, reflux condenser and a thermometer.

Results: On the basis of the results obtained from the study the optimal conditions of polymerization process of pyrocondensate in the presence of bimetallic catalytic complexes were: concentration of catalyst for oligomerization process of pyrocondencate and its fractions – 0,5% wt., temperature  for pyrocondensate and C6-C8 fraction – 70ºC, temperature for C5 fraction – 60ºC, reaction time for pyrocondensate – 1 hour., C5 and C6-C8 fractions - 40 min. Increasing the molecular weight of petroleum polymer resins synthesized in the presence of bimetallic catalytic complexes from 700 to 1200 resulted in film formation.

Conclusion: The best activity of bimetallic catalysts in the oligomerization process of pyrocondensate and its fractions was observed at a ratio Al:Me=8:1, so in that time the concentration of catalyst decreased from 1 % wt. to 0,5 % wt. It was noticed that bimetallic catalysts oligomerized the unsaturated hydrocarbons of pyrocondensate and its fractions and separated benzene-toluene-xylenes fraction and C5 fraction which can used as benzene component with high purity. Also the bimetallic catalytic complex made possible the synthesis of PPR, which can be used as film forming material in lacquer industry as well as modifier for bitumen in road-coating industry.

 

Open Access Original Research Article

Consequence Modeling of Chlorine Release from Water Treatment Plant

Naimeh Setareshenas, Mir Mohammad Khalilipour, Farhad Shahraki, Mohsen Mansouri

Chemical Science International Journal, Page 97-104
DOI: 10.9734/ACSJ/2014/5961

In the recent years, world has seen a wide range of major accidents with a number of fatalities, economic losses, and damage to the environment. These accidents can lead to serious danger to human health and the environment which can be occurred inside or outside the establishment. Consequence assessment is very important to predict and prevent deleterious effects of these events. Chlorine is a toxic material that is used in Water Treatment Plants as disinfectants. The aim of this study is to determine and identify the locations with high risk near the water treatment plant of Rasht, in the north of Iran. In this paper the modeling of chlorine release has been investigated for water treatment plant by using PHAST (Process Hazard Analysis Software Tool) software. According to the result of modeling the rupture of chlorine vessel in F stability class is the worst possible Release scenario because it has been affected more distance than other scenarios. The probability of fatality is %100 in each 3 stability class for the point located at 100 meter downwind. Thus the surrounding land of this plant is non-residential for this distance and the suitable recommendation should be considered to decrees risk of chlorine release.

 

Open Access Original Research Article

Bioglycerol Conversion in the Reverse Vortex Gas Flow Plasma-Liquid System (Tornado-Type) with Liquid Electrode and Addition of CO2

V. Ya. Chernyak, O. A. Nedybaliuk, O. V. Solomenko, E. V. Martysh, Iu. P. Veremii, I. I. Fedirchyk, T. E. Lisitchenko, L. V. Simonchik, V. I. Arhipenko, A. A. Kirilov, A. I. Liptuga, V. P. Demchina, S. M. Dragnev

Chemical Science International Journal, Page 105-116
DOI: 10.9734/ACSJ/2014/4352

Bioglycerol (crude glycerine) usually consists of – 35-50% glycerine, 10-20% methanol and soap mixture and the initial vegetable oil esters. It is a by-product of the biodiesel production. However, the direct combustion of bioglycerol is dangerous, because this combustion has by-product – acrolein (acrylic aldehyde). Acrolein is very toxic and flammable substance. Along with this, bioglycerol can be used to generate syngas. In this paper describes the bioglycerol reforming, which uses the combined system that includes plasma processing and handling in the pyrolysis chamber. The studied plasma source is the "tornado" type reverse vortex gas flow plasma-liquid system with a liquid electrode. The working gas is a mixture of air and CO2. The bioglycerol or mixture of bioglycerol and distilled water have been used as the working liquids. The present article describes the stable operation regime: current-voltage characteristics of the discharge, emission spectrum of the plasma, transmission spectra and composition of gas at the outlet of the system. It is shown that the energy efficiency under bioglycerol reforming is higher than during the ethanol reforming at the same CO2/air flow ratios in the input gas.

 

Open Access Original Research Article

Synthesis, Characterization, Spectral (FT-IR, 1H, 13C NMR, Mass and UV) and Biological Aspects of the Coordination Complexes of Sulfur Donor Ligands with Some Rare Earth Elements

R. V. Singh, Pradeep Mitharwal, Ritu Singh, S. P. Mital

Chemical Science International Journal, Page 117-137
DOI: 10.9734/ACSJ/2014/6929

Bio-potent ligands, 2-hydroxy-N-phenylbenzamide hydrazinecarbothioamide(HPHTSCZH2) and 2-hydroxy-N-phenylbenzamide hydrazine carbodithioic benzyl ester (HPHCBESH2) have been synthesized by the condensation of 2-hydroxy-N-phenylbenzamide with hydrazinecarbothioamide and hydrazine carbodithioic benzyl ester, respectively and reacted with hydrated lanthanide chlorides.  The coordination moieties of the ligands have been confirmed by various spectral studies. Elemental analyses suggested  that the complexes have 1:2 stoichiometry which were characterized further by magnetic moment, infrared, EPR, electronic, 1H NMR, 13C NMR and mass spectral studies. TGA studies were also conducted for one of the representative compound to analyze the presence of water molecule. The spectral studies confirmed the proposed framework of the new lanthanide complexes and indicated an octahedral geometry around the central metal atom. On the basis of X-ray powder diffraction study one of the representative  Sm complex was found to have Hexagonal Lattice type, having Lattice Parameters: a = 18.528 Aº,   b = 18.528 Aº and  c = 20.675 Aº and α = 90º, β = 90º and γ =120º. The free ligands and their metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties and in vivo for antifertility activity on male albino rats. Both the ligands and their complexes were found to possess appreciable fungicidal, bactericidal and antifertility activities.