Open Access Short communication

A 100% Water Mobile Phase HPLC-PDA Analysis of Tetracycline Antibiotics

Naoto Furusawa

Chemical Science International Journal, Page 500-506
DOI: 10.9734/ACSJ/2013/3868

Aims: To develop a reserved-phase HPLC method for detecting oxytetracycline (OTC), tetracycline (TC), and chlortetracycline (CTC) using a 100% water mobile phase.

Study Design: HPLC conditions.

Place and Duration of Study: Author’s Lab., Osaka City University, Japan, between September and November 2012.

Methodology: Chromatographic separations were performed an Inertsil® WP300 C4 (100×4.6 mm, 5 μm) with a water mobile phase and a photodiode-array detector.

Results: The run time was < 5.5 min.  The method shows high stability, significant linearity and satisfactory sensitivity.  The detection limits were established in the range 0.01 – 0.059 μg/mL.

Conclusion: An organic solvent/reagent-free HPLC method for the simultaneous detection of OTC, TC, and CTC was developed and may be further applied to the quantification in foods.

 

Open Access Original Research Article

Thieno[2,3-d]Pyrimidin-4-Ones. Part 3.* Electrophilic Ipso-Substitution Reactions of Methyl and Methoxycarbonyl Groups

B. Zh. Elmuradov, Kh. A. Bozorov, А. Zh. Kurbanbayeva, I. S. Ortikov, Kh. M. Bobakulov, N. D. Abdullayev, A. Yili2, H. A. Aisa, Kh. М. Shakhidoyatov

Chemical Science International Journal, Page 364-377
DOI: 10.9734/ACSJ/2013/4203

Interactions of 5,6-dimethyl- (1), 3,5,6-trimethylthieno[2,3-d]pyrimidin-4(3H)-ones (2) and 2,3-dimethyl- (5-7), 2-methyl-3-methoxycarbonylthieno[2,3-d]dihydropyrrolo-, -tetrahydropyrido-, tetrahydroazepino[1,2-a]pyrimidin-4-ones (14-16) with nitrating mixture were investigated. For the first time it is shown, that in dependence on the presence of substituent in position 2 and 3 of pyrimidine and thiophene rings reaction goes in various directions; by electrophilic ipso-substitution of methyl groups at C-5 by nitro group, or its oxidation up to carboxyl groups with formation corresponding 5-carboxy derivatives. It is revealed, that at absence of the substituent in position 3 (compound 1) the electrophilic ipso-substitution of methyl group by nitro group with formation of 5-nitro derivative took place. It is found, that at interaction of compounds 2,5-7, 14-16 with nitrating mixture instead of substitution of methyl groups at C-2, goes in an unexpected direction, i.e. there are oxidation of methyl groups or electrophilic ipso-substitution of methoxycarbonyl groups in position 3 by nitro group.

Open Access Original Research Article

Spectrophotometric and Chromatographic Methods for the Estimation of Raloxifene Hydrochloride in Bulk and Pharmaceutical Formulations

Bahia A. Moussa, Ramzia I. El-Bagary, Essam Eldin A. Osman

Chemical Science International Journal, Page 378-386
DOI: 10.9734/ACSJ/2013/4598

Aim: To develop simple, accurate and precise spectrophotometric and chromatographic methods for the estimation of Raloxifene Hydrochloride (RXF) in pure and pharmaceutical dosage forms.

Study Design: Spectrophotometric and chromatographic methods.

Place of Study: Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Egypt.

Methodology: The differential spectrophotometric method was based on the measurement of the absorbance difference (∆A) at 333.4 nm of alkaline raloxifene hydrochloride solutions in 0.1 N NaOH against its acidic solutions in 0.1N HCl. RP-HPLC was developed  using benzophenone as an internal standard, where the mobile phase used was acetonitrile: water (50:50, v/v), delivered at a flow rate of 1.2 ml/min on a stationary phase composed of C18 column; and the detection was carried out at the λmax of RXF (289 nm).

Results: The recovery percentage for RXF was found to be 100.46 ±0.65 and 99.96 ±0.83 for the two methods, respectively. The methods were validated as per ICH guidelines regarding accuracy, precision and system suitability.

Conclusion: All the results obtained were found to be within the acceptable limits. The methods were successful to estimate RXF in bulk powder and pharmaceutical preparation Evista ®.

 

Open Access Original Research Article

Photocatalytic Activity of Titanium Oxide – Iron Oxide Coatings Prepared by Plasma Spraying

P. Ctibor, V. Stengl, Z. Pala

Chemical Science International Journal, Page 387-400
DOI: 10.9734/ACSJ/2013/4745

This study examines the photocatalytic activity of coatings produced by atmospheric plasma spraying (APS). The spraying tool used is a water-stabilized plasma gun WSP. The TiO2– Fe2O3 powder with and without Na2SiO3 additive was agglomerated to build particles suitable for feeding into the plasma jet and spraying. The coatings are analyzed by scanning electron microscopy, X-ray fluorescence and X-ray diffraction. Photocatalytic degradation of acetone as well as the growth kinetics of the products - carbon dioxide and carbon monoxide - is quantified for both coating types and compared with a pure TiO2 coating. The coatings show a lamellar structure, as is typical for this technological process. However the porosity is rather high. Anatase titania from the feedstock powder is converted to rutile phase whereas a presence of FeTiO3 is detected in the coating without Na2SiO3. The coating from powder with Na2SiO3 admixture is amorphous. Both coatings are more photocatalytically active than the reference TiO2 coating.  

 

Open Access Original Research Article

Synthesis and Studies on Some Spiro and Fused of Quinone Derivatives

H. A. Soleiman, A. K. Khalafallah, A. M. H. Sorry

Chemical Science International Journal, Page 401-418
DOI: 10.9734/ACSJ/2013/3213

Some new Spiro β-lactam, Spiro thiazolidine derivatives were synthesized by the reaction of new Schiff bases (5a-c, 8a-c ) with chloroacetyl chloride and/or mercaptoacetic acid to give new Spiro β-lactam (6a-c, 9a-c ) and new Spiro thiazolidinone derivatives (7a-c, 10a-c ) . Also, new fused pyrazolo derivatives (12a-c, 13a-c) fused isoxazolo derivatives (14a-c) and pyrimidine derivatives (15a-c, 16a-c) were synthesized by the reaction of new arylidine derivatives (11a-c) with hydrazine hydrate, phenyl hydrazine, hydroxylamine hydrochloride, urea and thiourea, respectively.

Open Access Original Research Article

A Combined Experimental Green Flow-Injection Procedure and Computational Analysis to Determine Amino Acids

Samy Emara, Tarek Aboul-Fadl, Abdel Nasser El-Shorbagy, Maha Kamal, Walaa Zarad, Mohamed Abdel Kawi

Chemical Science International Journal, Page 419-433
DOI: 10.9734/ACSJ/2013/4923

Aim: Methods of pollution reduction and human health protection would be more successful if the fields of green analytical chemistry and computational analysis could come together. This overlap would help to minimize, or even eliminate the use and generation of hazardous substances. The goal of this study was to identify a way of further developing the fields of green analytical chemistry and computational analysis.

Place and Duration of Study: Misr International University, between April 2011 and November 2012.

Methodology: A single-line flow-injection (FIA) packed-reactor technique has been developed for the analysis of amino acids. Amino acids were injected into a flowing stream of distilled–deionized water, carried through the packed reactor of CuO followed by UV detection. The flow rate was 1.25 mL/min and the column temperature was ambient (25 °C). New mathematical models for correlations of the physicochemical parameters of the CuII-amino acid complexes with analytical parameters such as lower limit of detection (LOD), lower limit of quantitation (LOQ) as well as lower limit of linearity range (LL) and higher limit of linearity range (HL) were employed.

Results: The developed procedure can accommodate sample frequency of 60 sample/hrand a recovery% ranging from 98.800% to 100.260%. A good accordance was observed between the computed values of LOD, LOQ, LL and HL and the observed results.

Conclusion: An extremely simple environmentally friendly analytical procedure including packed-reactor FIA technique has been developed and evaluated for the routine quality control of amino acids. The developed method has excellent sensitivity and accuracy, as well as, it required relatively simple and inexpensive instrumentation. A good correlation between the computed values and the FIA results suggests that the mathematical models are reliable, and hence provide a theoretical basis for the determination of amino acids.

 

Open Access Original Research Article

Persistent Organochlorine Compounds in the Water and Sediment Samples from the Lake Bosomtwe in Ghana

Samuel Afful, Johannes A.M. Awudza, Shiloh Osae, Stevester K. Twumasi

Chemical Science International Journal, Page 434-448
DOI: 10.9734/ACSJ/2013/3913

Aims: To investigate the burden of organochlorine pesticides (OCPs) and its degradation products as well as indicator polychlorinated biphenyl (PCBs) in the water and sediments.

Study Design: This investigation involved one year monitoring of the Lake.

Place and Duration of Study: Lake Bosomtwi was the study area and analysis of samples was carried out at the Nuclear Chemistry and Environmental Research Centre of Ghana Atomic Energy Commission from January 2012 to February 2013. Samples were collected three times during dry, wet and minor wet seasons.

 Methodology: Liquid-liquid extraction with hexane was used for the water samples while sediment samples were sonicated on ultrasonic bath with hexane/acetone mixture (3:1). The extracts were then cleaned up with florisil and quantified on a micro-capillary gas chromatography equipped with electron capture detector.

 Results: Eight OCPs and four indicator PCBs were detected in water while sixteen OCPs and five indicator PCBs were also detected in the sediments.  The highest OCPs concentration in water was 6.35 µg/l while that for the sediments was found to be 15.23 µg/kg. The total PCBs load (sum of all indicator PCBs) ranged from 1.09 – 7.19 µg/l and 6.43 – 19.17 µg/kg for the water and sediments respectively.

Conclusion: The study has shown that organochlorine compounds are present in the Lake Bosomtwi. The detection of organochlorine pesticides in water and sediments could be attributed either to historical use of these chemicals for agricultural purpose or environmental transport of these chemicals to the study area. The presence of indicator polychlorinated biphenyls could on the other hand be attributed to release to the environment during anthropogenic processes such as incineration, combustion and smelting.  Leakages from refuse dumps containing dumped transformers and capacitors could also be a contributor to PCBs presence in the Lake.

 

Open Access Original Research Article

Sorrel (Hibiscus sabdariffa) Seed Oil Extraction Optimization and Quality Characterization

E. Betiku, T. F. Adepoju

Chemical Science International Journal, Page 449-458
DOI: 10.9734/ACSJ/2013/2777

Aims: This study was aimed at separating seed oil from sorrel (Hibiscus sabdariffa) oilseeds using application of solvent extraction method. The process was optimized using response surface methodology and the quality of the seed oil was determined.

Methodology: Optimization of oil extraction from the oilseeds using response surface methodology was carried out. The effects of three independent factors (extraction time, solvent volume and sample weight) and their respective interactions on the response, oil yield, were investigated. A total of 17 experimental runs were generated using Box-Behnken design. The extracted seed oil was characterized to determine its quality.

Results: A quadratic polynomial was obtained to predict the oil yield and the ANOVA test showed the developed model to be significant (P < 0.05). A statistical model predicted the maximum seed oil yield to be 18.25% at the optimal condition of sample weight, 22g, solvent volume, 157 ml and time, 2 h. The optimized condition was validated with the actual oil yield of 17.85%, which was well within the range predicted. The seed oil analysis showed the physical state of the oil to be liquid/yellow-greenish in colour, specific gravity 0.886 ± 0.026, viscosity (at 40ºC) 15.40 cP, p-anisidine value 6.31, Totox number 16.31, %FFA 0.40 ± 0.01, acid value 0.80 ± 0.01 mg KOH.g oil-1, saponification value 197.75 ± 0.05 mg KOH.g oil-1, iodine value 97.77 ± 0.02 g I2.100 g oil-1, peroxide value 5.00  ± 0.01 meq O2.kg oil-1 and cetane number 51.90 ± 0.1. The fatty acid profile of the oil revealed that it is highly unsaturated (76.45%) with linoleic acid the highest (44.39%).

Conclusion: The physicochemical analysis of the sorrel seed oil indicated it is edible and could serve as feedstock for many industrial applications.

 

Open Access Original Research Article

Level of Selected Metals in Water, Sediment and Fish Samples from Itapaji Dam, South-Western, Nigeria

Adefemi Oluyemi Samuel

Chemical Science International Journal, Page 459-467
DOI: 10.9734/ACSJ/2013/4988

The level of metals (Zn, Fe, Pb, Cu, Mn, Cr, Na, Mg, Ca and K) in water, sediment and fish samples from Itapaji dam for both dry and wet seasons in two years were determined using standard analytical methods. The concentrations of metals were higher in dry season than those of wet season for the two years of study. In all the samples, concentrations of metals in sediment samples were higher than those of fish samples while the concentrations of the fish samples were higher than that of water samples. However, concentration of metals in water and fish samples were below the safety limit, hence the water can be purified for domestic use and the fish sample can be consumed by man. A close monitoring of the dam year by year is necessary.

 

Open Access Original Research Article

Densities, Viscosities and Ultrasonic Studies of Binary Liquid Mixture of Ethylamine and Benzyl Alcohol at Different Temperatures

Chandra Mohan Saxena, Archna Saxena, Ashok Kumar Srivastava, Naveen Kumar Shukla

Chemical Science International Journal, Page 468-478
DOI: 10.9734/ACSJ/2013/5229

Ultrasonic studies, densities and viscosities of binary liquid mixture of ethylamine and benzyl alcohol have been measured at different temperatures at 30ºC, 35ºC and 40ºC. The experimental value of speed of sound (u), isentropic compressibility (βs), intermolecular free length (Lf), viscosity (η), available volume (Va), molar volume (Vm) and Nissan’s parameter (d)  have been calculated of ethyl amine and benzyl alcohol in the pure state as well as mixture over whole composition range were measured at 30ºC, 35ºC and 40ºC. These properties also provide important information about molecular packing, molecular motion and various types of intermolecular interactions and their strength, influenced by the size shape and chemical nature of component molecules.

 

Open Access Original Research Article

Solvent Extraction Studies of Uranium (VI) from Aqueous Media into Chloroform Solution of N,N´-ethylenebis(4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-oneimine)

U. J. Chukwu, J. Godwin

Chemical Science International Journal, Page 479-488
DOI: 10.9734/ACSJ/2013/4155

The extraction of Uranium (VI) from aqueous media of varying pH values (0.3 – 9.0) was studied using chloroform solution of 0.05M N,N`-ethylenebis(4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H- pyrazol-3-oneimine) (H2PrEtP) Schiff base. The effect of 4-propionyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (HPrP) as a mixed ligand in these  extractions  was  also  studied.  The ligand H2PrEtP was shown to behave in solution as a very weak acid with potentiometrically determined acid dissociation constants pKa of 6.1±0.1 and 7.6±0.1. Colorimetric method was used to determine the Uranium(VI)  concentrations  in  aqueous  media  after  extraction processes. Slope analysis showed that the extracted uranyl complexes were UO2(HPrEtP).X in the absence of the mixed ligand (H2PrEtP/HPrP) and UO2(HPrEtP)HPrP.X in the presence of HPrP as a mixed ligand, with the excess anion X- coming from the buffers. The pH1/2 shifted from 6.9 ± 0.10 for H2PrEtP to 4.4 ± 0.10 for H2PrEtP/HPrP organic mixture. Though, log Kex values (-5.84 ± 0.18 log Kex H2PrEtP) > -8.71 ± 0.50 log Kex H2PrEtP/HPrP) indicated that the formation constant for UO2(HPrEtP).X was higher than that for UO2(HPrEtP)HPrP.X. Thus, the mixed ligand organic phase was shown to be a better extractant for Uranium(VI) with a wide extraction pH range of 4.0–6.5, a higher partition coefficient(KD) of 2.49 and quantitative extraction of 99.9% compared to extraction pH range of 7.75 – 8.75 and KD of 1.49 when H2PrEtP was used alone.

 

Open Access Original Research Article

Thermodynamics of the Solvation of Lead Nitrate in Mixed DMF-H2O Solvents at 301.15 K

Esam A. Gomaa, Elsayed M. Abou Elleef

Chemical Science International Journal, Page 489-499
DOI: 10.9734/ACSJ/2013/4343

Aims: The aim of this study is to determine thermodynamic energies of the solvation of lead nitrate in mixed DMF-H2O solvents at 301.15 K. The Gibbs free energies as a very important thermodynamic property were evaluated for Pb(NO3)2 in mixed dimethylformamide DMF-H2O solvents at 301.15 K from the experimental solubility measurements. The ratio of the ionic between lead and nitrate ions was used to divide the total Gibbs free energy of the salt into its individual contribution in the mixtures used. Libration Gibbs free energy associated with moving Pb(NO3)2 in standard gas state to standard state in solution was evaluated according to specific cycle for the solvation process using the solubility product. Also the lattice energy for Pb(NO3)2 (cr) was also calculated and used for further evaluation (the symbol (cr) denotes the crystalline phase).  The conventional Gibbs free energies for the cation (Pb2+) and anion (NO3-) were estimated theoretically and also the Gibbs free energy of NO3- gas was evaluated and all values were discussed.

Place and Duration of Study: Chemistry Department, Faculty of Science, Mansoura University and Basic Science Department, Delta Higher Institute for Engineering and Technology, Dalkha , Mansoura, Egypt, between June 2012 and July 2013.

Open Access Original Research Article

Mechanical Properties of Wood Waste Reinforced Polymer Matrix Composites

R. O. Medupin, O. K. Abubakre, K. O. Ukoba, P. E. Imoisili

Chemical Science International Journal, Page 507-513
DOI: 10.9734/ACSJ/2013/5637

This research work set is an investigation into the mechanical properties of polymer matrix composites (PMC) produced by the use of wood waste. Low density polyethylene was reinforced with sawdust from African teak as a filler, and Sodium hydroxide as the binder. The composite were fabricated by a compression moulding technique; composites with amounts of wood waste ranging from 20, 30, 40, 50, and 60 wt. % were produced. Results indicated that 40% of wood waste was the optimum reinforcement. Increasing amount of reinforcement improves the strength and stiffness of the composites but decreases the impact strength. The results also suggests that the rate of water absorption of the composite was high in the first few hours and that the highest water absorption rate was observed with 60% reinforcement. Microstructural examination revealed that there were small discontinuities and a reasonably uniform distribution of wood particles in the polymer matrix.

 

Open Access Original Research Article

Spectrophotometric Method for the Determination of Cefotaxime Sodiumand Cefoperazone Sodium in Pure and Pharmaceutical Dosage Forms

Rania Adel Sayed, Wafaa Sayed Hassan, Magda Yossif El- Mammli, Abdalla Shalaby

Chemical Science International Journal, Page 514-525
DOI: 10.9734/ACSJ/2013/5572

Accuratespectrophotometric method was developed for the estimation of cefotaxime sodium (I) andcefoperazone sodium (II) in both pure and pharmaceutical dosage forms. The method is based on the reaction of the amino groups of the cited drugs with ninhydrin reagent producing a colored product which absorbs maximally at 568 nm. Beer's law was obeyed in the concentration range of (10-90) and (60-350) μg.mL-1 for drug (I) and (II) respectively .The correlation coefficient (r2),molar absorptivity (ε), sandell sensitivity, detection (LOD) and quantitation limits (LOQ) for the studied drugs were calculated. The proposed method was successfullyapplied for the determination of certain pharmaceutical dosage forms containing the studied drugs.

 

Open Access Original Research Article

Mechanical Properties of Cocoa-Pod/Epoxy Composite; Effect of Filler Fraction

P. E. Imoisili, T. C. Ezenwafor, B. E. AttahDaniel, S. O. O. Olusunle

Chemical Science International Journal, Page 526-531
DOI: 10.9734/ACSJ/2013/5526

In this study the mechanical properties of an agricultural waste (cocoa pod) in a polymer matrix (Epoxy resin) was investigated, and the effect of volume fraction of cocoa pod/epoxy resin composite was also investigated, different filler volume fraction (viz. 5 to 30 weight %) were fabricated, tensile and flexural test were performed according to ASTM D638, and ASTM D790, test results reveal that tensile and flexural strength of the composite decrease with filler volume fraction, while tensile modulus, flexural modulus and micro hardness of the composite increase with the increase in filler volume fraction. Morphological studies reveal that there is good dispersion of filler in the polymer matrix.

 

Open Access Original Research Article

Studies on Quinolin-2(1H)-One Derivatives: Synthetic Access to Pyrano[3,2-c] Quinoline and 3-Substituted Quinoline Derivatives

Fathy M. A.El-Taweel, Abdel- Ghani A. Elagamey, Muhammad H. M. Khalil

Chemical Science International Journal, Page 532-549
DOI: 10.9734/ACSJ/2013/3318

4H-pyrano[3,2-c]quinoline derivatives 6a-f were prepared via reacting arylmethylenemalononitriles 2-c,g with 4-hydroxyquinolines 1a-c or 1e,f. Refluxing  6d  with formic acid or acetic anhydride gave 7-(2-chlorophenyl)-5-methyl-5H-pyrimido [5'4':5,6]pyrano[3,2-c]quinoloine-6,8-(7H,11H)-dione 7 and 7-(2-chlorophenyl)-5,10-dimethyl-5H-pyrimido [5'4':5,6] pyrano[3,2-c] quinoloine-6,8-(7H,9H)-dione 9 respectively.Reacting 1d with 2a,d  gave pyrano[2,3-b] pyridine12a,b.Compounds 1c or 1g reacted with 2e,f to give  11-amino-8-oxo-9-substituted -5,6,8,9-tetrahydro-4H-pyrano[3,2-c]pyrido[3,2,1-ij]quinoline-10-carbonitriles 15a,b. Reacting 1c or 1g with ethoxymethylenemalononitrile 16 afforded 11-imino-4H,5H,6H,9H-benzo[ij][2,3-b]quinolizin-8-one 18. Also, reacting 1c or 1g with methyl 2-benzolyamino-3-dimethylaminopropionate 19 yield N-(6-(1-hydroxy-3-oxo-3,5,6,7-tetrahydropyrido[3,2,1-ij]quinolin-2-yl)-2-oxo-2H-pyran-3-yl)benzamide 21 and N-(8,11-dioxo-5,6,8,11-tetrahydro-4H-pyrano[3,2-c]pyrido[3,2,1-ij]quinolin-10-yl)benzamide 22 respectively. Condensation of 1c with aromatic aldehydes afford 2,2'-(arylmethylene)bis(1-hydroxy-6,7-dihydropyrido[3,2,1-ij]quinolin-3(5H)-ones) 28a-d.