Open Access Original Research Article

Kinetics and Mechanistic Study of Redox Reaction of Cobalt (III) Complex with L-Ascorbic Acid in Aqueous Acid Medium

Sadhana Senapati, A. K. Patnaik, S. P. Das, P. Mohanty

Chemical Science International Journal, Page 1-10
DOI: 10.9734/ACSJ/2015/15141

The kinetics of the electron transfer reaction of L-ascorbic acid with a cobalt (III) complex has been studied spectrophotometrically over the range 0.01 ≤ [ascorbic acid], mol dm-3 ≤ 0.07, 3.3 ≤ pH ≤ 5, and at 298 ≤ T, K ≤ 318 in aqueous acid medium. Kinetics measurements were run under pseudo-first order conditions. The rate of electron transfer reaction was found to be first order with respect to ascorbic acid. The results showed that the rate constant depends on size and strength of the ligand. The activation parameters favoured the electron transfer reaction. In the absence of evidence of direct coordination of ascorbic acid to Co(III) centre, an outer-sphere electron  transfer  mechanism was suggested. The reduction of Co(III) complex by L-ascorbic acid depends on pH  and the nature  of the ligand. Considering the dependence of kobs with pH, it was suggested that HAreacts much faster than H2 A and A2─ is not reactive at pH< 5. HAis the predominant reacting species under the experimental pH of the solution.

 

Open Access Original Research Article

Synthesis of Novel Methylidene Bridged Quinazoline-Isoquinoline Alkaloids

Sherzod N. Zhurakulov, Burkhon Zh. Elmuradov, Valentina I. Vinogradova

Chemical Science International Journal, Page 1-7
DOI: 10.9734/ACSJ/2015/19859

Interaction of 3-hydroxymethylidene-1,2,3,9-tetrahydropyrrolo[2,1-b]-quinazolin-9-one (2) with 1H(aryl)-6,7-dimethoxytetrahydroisoquinolines (3a-f) leads to the formation of novel methylidene bridged quinazoline-isoquinoline alkaloids. By results of IR- and 1Н-NMR – spectroscopy are shown that the synthesized products have enamine form and E-configuration.

 

Open Access Original Research Article

Effect of Solid Waste Source (Dumpsite Type) on Heavy Metal Contaminations in Urban Soils of Bauchi, Nigeria

Eze Michael Onyedika

Chemical Science International Journal, Page 1-14
DOI: 10.9734/ACSJ/2015/18039

Heavy metals constitute a major threat to humans due to the fact that they unlike some other pollutants are not biodegradable. Different Sources of these metals when dumped with municipal solid wastes raise the level of heavy metals in dumpsites. A study of the effect of solid waste source on heavy metal contaminations in urban soils of Bauchi, Nigeria was carried out using Atomic Absorption Spectrophotometer. Single and integrated pollution indices were used to assess the impact of human activities on the concentration of heavy metals in soils. The results obtained show that heavy metal contamination of urban soils in Bauchi is strongly affected by the source area of waste materials or the dumpsite type. Heavy metal contaminations based on single pollution indices used give the following trend: Pb > Cd > Ni > Zn > Cr > Mn > Cu >Fe for residential soils; Pb > Ni > Cd > Zn > Cr > Mn > Cu > Fe for commercial soils and Pb > Cd > Ni > Zn > Cu > Cr > Mn > Fe for industrial soils. In view of the discrepancies in results obtained when different reference values are used, the development of a unified contamination classification model named Unified Contamination Classification by Eze at Bauchi (UCCEB) was undertaken resulting in interesting coherence among single pollution indices. The application of UCCEB model enabled the differentiation of anthropogenic-related contaminations from lithogenic-related inputs. The studied sites gave the following results using UCCEB: Residential dumpsite (RES): moderate pollution with respect to Cd, Ni, Pb, Zn; low pollution with respect to Cr, Cu, Mn; and deficient pollution with respect to Fe. Commercial dumpsite (COM): moderate pollution with respect to Cd, Cr, Ni, Pb, Zn; low pollution with respect to Cu, Mn; and deficient pollution with respect to Fe. Industrial dumpsite (IND): moderate pollution with respect to Cd, Cr, Cu, Ni, Pb, Zn; low pollution with respect to Mn; and deficient pollution with respect to Fe. Thus the order of multi-element contamination can be summarized as IND>COM>RES.

 

Open Access Original Research Article

Hydrodynamic Behaviour of Common Salt Water (NaCl Solution) in a Glass-beads Packed Cylindrical Fluidized Bed

Harekrushna Sutar, Kashinath Barik, Anup Kumar Bairagi, Rabiranjan Murmu

Chemical Science International Journal, Page 1-6
DOI: 10.9734/ACSJ/2015/20086

The research paper focuses on to design a laboratory scale cylindrical fluidized bed column. The column was fabricated successfully having a height of 1.5 m and 5 cm inner diameter. Glass beads of spherical shape are packed up inside the column up to 2.4 cm height having 8 mm size. Sodium Chloride (NaCl) salt water solution of different concentrations (1-5 kg salt + 1.3 m3 of water) has been implemented to characterize the hydrodynamic properties. Results are compared for each concentration with pure water as normal practice considering flow rate, pressure drop across the bed and distributor plate, bed height, bed void fraction and finally bed expansion ratio as variables prevailing an interesting conclusion which may needful towards engineering literature.

Open Access Original Research Article

Identification of Thymol as an Antitubercular Agent from Ocimum gratissimum Leaf Essential Oil

Samuel E. Okhale, Peters Oladosu, Abayomi T. Orishadipe, Joseph I. Okogun

Chemical Science International Journal, Page 1-6
DOI: 10.9734/ACSJ/2015/19141

Ocimum gratissimum consumed as a vegetable is used to treat cough, tuberculosis and dysentery in Nigeria. Hydro-distillation of the fresh leaves of O. gratissimum yielded a golden yellow essential oil 0.5% v/w which exhibited minimum inhibitory concentration (MIC) of 48 µg/ml against Mycobacterium bovis BCG strain. Activity-guided fractionation of the oil into neutral and acidic portions followed by column chromatography led to the isolation of a crystalline compound with MIC of 9.8 µg/ml while the control drug isoniazid had MIC of 0.07 µg/ml. GC-MS and 1H NMR analyses revealed the bioactive crystalline compound to be thymol.

 

Open Access Original Research Article

Effect of Pre-planting Seed Dressers on Serum Enzymes of Laying Chickens

I. O. Adejumo, A. D. Ologhobo, T. O. Babalola

Chemical Science International Journal, Page 1-5
DOI: 10.9734/ACSJ/2015/19687

The study was conducted to assess toxicity of synthetic insecticides in chickens. Twenty-five week old Nera black pullets (n=48) were fed with pre-planting insecticide-treated diets at recommended doses (T1=control, T2=2 g dressforce /Kg grains, T3=2.5 g apronstar /Kg grains, T4=2.5 g seedrex /Kg grains) for 14 days. Serum enzymes were assessed using standard procedures. Each treatment had 3 replicates. Data were analysed using analysis of variance at α0.05. Serum enzymes were significantly (P=0.05) elevated for aspartate aminotransferase (AST), alanine aminotransferase (ALT) alkaline phosphatase (ALP) for treatment diets. No mortality was recorded throughout the period of the experiment. Synthetic insecticides used resulted in liver dysfunction of chickens. Hence, alternative cheap bio-insecticides should be sourced.

 

Open Access Review Article

Comparison of Analytical Techniques in the Characterization of Complex Compounds

F. S. Nworie, F. I. Nwabue, W. J. O. Oti

Chemical Science International Journal, Page 1-19
DOI: 10.9734/ACSJ/2015/20257

The methods of characterization of complex compounds with the intent of their applicability in identification procedures have been critically appraised. In this work, the principle, sensitivity, selectivity and applicability of the different analytical techniques have been systematically presented. The analytical techniques were compared based on the strength of information provided for, which is germane for complex compound identification.