Open Access Original Research Article

Determination of Pb in Ibadan Metropolis —An Indication of Environmental Pollution

Johnson Dele Ogunkolade, O. Owolabi, K. J. Akinluwade, A. M. Adegoke, D. A. Isadare, A. R. Adetunji

Chemical Science International Journal, Page 270-276
DOI: 10.9734/ACSJ/2015/10566

This study determined the Pb pollution levels of lead (Pb) in Ibadan. Until 1970, Ibadan was the largest city in Sub-Saharan Africa and the current largest city in West Africa. Dust samples were randomly collected from selected sites, cleaned, air-dried and sieved. Pb level was determined in the samples by partial metal extraction. The average level of Pb in the house-hold dust of houses around heavy traffic areas was the highest followed by industrial area and then housing estate. It was observed that the Pb content decreased with increase in house distance from industrial area; there was rapid decrease in the level of Pb with distance. The result suggested that residential houses should be situated far away from industrial and heavy traffic areas and there should be authorized guidelines for placing industrial estates and major roads.

 

Open Access Original Research Article

The Effect of Acacia senegal Leaf Extract on the Flammability of Flexible Polyurethane Foam

Baffa Abubakar, P. O. Ikeh, U. Z. Faruq, H. M. Maishanu

Chemical Science International Journal, Page 277-284
DOI: 10.9734/ACSJ/2015/12506

Health and environmental consequences of conventional flame retardants necessitated the incorporation of new plant based flame retardants. According to Australlian Plant Society all Acacia species can be used as fire retardants which lead to the selection of the leaves of Acacia senegal as a flame retardant on flexible polyurethane foam. GC-MS analysis revealed the presence of phosphorus and nitrogen compounds. Add on percentage  ranged from 10-20%, Ignition time from 8-17 seconds, flame propagation rate ranged between 0.33-0.10 cm/s , after glow time ranged from 25-5 seconds and char formation ranged from 23-30%. The flammability characteristics of the flexible polyurethane foam was improved upon doping with the extract of the leaves of this plant.

 

Open Access Original Research Article

Analytical Method Development and Validation on Liquid Chromatography for Determination of the Drug Cefdinir by Using Tinidazole as an Internal Standard in Bulk and Pharmaceutical Dosage Forms

Gadapa Nirupa, Upendra M. Tripathi

Chemical Science International Journal, Page 285-296
DOI: 10.9734/ACSJ/2015/12275

The present work involves a rapid and reproducible HPLC method which was developed and validated for the estimation of the drug cefdinir in the bulk drug and pharmaceutical dosage forms. Tinidazole was used as an internal standard. In this method, the estimation was done by using C18 column (100 mm x 4.6 mm, 5 µm); mobile phase consisting of buffer and Methanol (80:20). Buffer was prepared by dissolving 0.025M of Potassium dihydrogen orthophosphate in 1000 ml of water. The pH was adjusted to 2.5 with Orthophosphoric acid; the flow rate of 1.8 mL/min and ultraviolet detection at 290 nm. The retention time of Cefdinir was found to be 2.9 min. The method was partly validated with respect to Precision, Linearity, Accuracy, Ruggedness and Robustness as per ICH guidelines. The validated method was successfully applied to the commercially available pharmaceutical dosage forms.

 

Open Access Original Research Article

Corrosion Behavior of V2AlC and Cr2AlC in 0.01 N Calcium Hydroxide at Four Temperatures

Rana A. Majed Anaee, Ahmed M. Al-Ghaban

Chemical Science International Journal, Page 297-303
DOI: 10.9734/ACSJ/2015/14902

Corrosion behavior of V2AlC and Cr2AlC materials have been investigated in 0.01N Ca(OH)2 at pH=11.7 using Potentiostat to estimate corrosion parameters. The results show that V2AlC material has more noble potential and lower current density than Cr2AlC over temperatures include 303, 313, 323 and 333K. Polarization resistance which calculated according to Stern-Geary equation confirms the most resistance for V2AlC in experimental conditions. The change in free energy was more negative for Cr2AlC than V2AlC, this means that V2AlC has less ability to corrosion. The negative value of ΔS for V2AlC confirms the later result. It`s known that corrosion rate depends on the value of the activation energy which is represents the energy maxima of intermediate transition states through which the entity must pass in transforming and the energy that must be acquired, from Arrhenius plots have been conducted that activation energy Ea for V2AlC was more than for Cr2AlC.

 

Open Access Original Research Article

Chemical Analyses of Volatile Compounds from Cuticular and Non-cuticular Abdominal Glands of African Weaver Ants (Oecophylla longinoda)

O. U. Igwe, P. N. Eze

Chemical Science International Journal, Page 304-312
DOI: 10.9734/ACSJ/2015/14255

Chemicals from the abdominal glands of African weaver ants (Oecophylla longinoda) were extracted with petroleum ether and fifteen pheromonal compounds were characterised using Gas Chromatography-Mass Spectrometry (GC/MS) Technique. The compounds analysed include decane (8.81%), undecane (5.97%), dodecane (4.52%), tridecane (1.75%), hexadecane (2.36%), methyl decanoate (3.31%), (3Z)-tetradec-3-ene (2.10 %), 2,6-dimethylheptadecane (13.29%), 11-octadecenoic acid methyl ester (17.01%), octanoic acid methyl ester (2.89%), 2-methyl nonadecane (11.92%), 1-fluorodecane (5.29%), (3E,11E)-tetradeca-3,11-dien-1-ol (12.02 %), cyclohexane-1,2-diol (3.71%) and 2-ethyl-1-decanol (5.07%). Fourier Transform-Infrared (FT-IR) analysis of the extract showed peaks at 1542.14, 1646.30, 2092.83, 2935.76 and 3427.62 cm-1 indicating the presence of alkene, alkyne, alkane and alcoholic compounds. These compounds consisted 50.72 % hydrocarbon, 23.21 % ester, 20.80 % alcohol and 5.29 % alkyl halide. The highest component was 11-octadecenoic acid methyl ester followed by 2,6-dimethylheptadecane. This investigation has shown that the cuticular abdominal chemicals derived from African weaver ants are mostly hydrocarbons, esters and alcohols which might be used by the insect as pheromone compounds.

 

Open Access Original Research Article

Reduction of 3,7-Bis(dimethylamino) phenazothionium Chloride by Benzenethiol in Aqueous Nitric Acid Medium: A Mechanistic Approach

S. O. Idris, J. O. Suleman, J. F. Iyun, A. A. Osunlaja

Chemical Science International Journal, Page 313-321
DOI: 10.9734/ACSJ/2015/11703

The kinetics of the reduction of 3,7-bis(dimethylamino)phenazothionium chloride (MB+) by benzenethiol in aqueous solution has been investigated in the acid range 0.3≤[H+  ≤ 0.9 mole dm-3, ionic strength (µ) of the reaction medium in the range: 0.4 ≤ µ ≤ 1.0 mole dm-3 (NaNO3) and temperature, T = 29ºC. The reaction is first order in both [oxidant] and [reductant] and display an inverse order acid dependence with an overall reaction that conforms to the rate law:

 [MB+]  = (Kk4[H+]-1 + k6)([MB+][ C6H5SH])

at [H+] = 0.3 mole dm-3 and µ = 1.0 mole dm-3 (NaNO3). The rate of the reaction increased with increase in the ionic strength and decrease in dielectric constant of the reaction medium. Added HCOO- and Cl- accelerated the rate of the reaction. Spectroscopic investigation did not reveal the formation of any stable reaction intermediate. Test for free radical was positive and a plausible mechanism consistent with these observations has been proposed.