Open Access Original Research Article

An Assessment of the Impact of Chemical Insecticides Used to Control Desert Locust (Schistocerca gregaria) (Orthoptera, Acrididae) on Lacertid Lizard Acanthodactylus spp (Sauria, Lacertidae) in Niger

Mamadou Abdou

Chemical Science International Journal, Page 193-200
DOI: 10.9734/ACSJ/2015/16556

Chemical treatments still constitute the main method used to control desert locust during the invasion phases. In addition to their relatively high costs, these pesticides are not target specific in the majority of the cases; they can have negative effects on the biotic and abiotic components of the ecosystem. The goal of our study, conducted under natural conditions, was the assessment of the ecological effect of ethyl chlorpyrifos and fenitrothion, the most widely used organophosphate pesticides in desert locust control in Niger. To assess the impact of pesticides on the relative abundance of lacertid lizard Acanthodactylus boskianus and Acanthodactylus sp before and after treatments, we used the method of pedestrian transect. The analysis of the variance was used to carry out a statistical comparison based on BACI (Before-After-Control-Impact) method. The experiments were carried out in a randomized complete block design with three replications. The experimental plots had an area of 16 ha each, the treatments consisted of ethyl chlorpyrifos at the rate of 225 ga.i./ha; fenitrothion at the rate of 450 ga.i./ha. Unsprayed plots were used as controls. These rates are those recommended by the Food and Agriculture Organisation of the United Nations (FAO) to control desert locust. Chemical treatments were carried out in total cover using a battery driven hand-held spinning disk sprayer (Micro-Ulva®), in accordance with the technical directives of the FAO for ultra-low volume applications. The field trial was carried out in the valley of Tafidet located in the eastern side of Aïr Mountains in Niger, from June to December of the years 2004 to 2006. Ineach experimental plot, two lines of 300 m length and 10 m width were used as area of counting. These lines of counting skirted one of the diagonals of each plot. The results demonstrate the noxious effect of ethyl chlorpyrifos and fenitrothion (organophosphate pesticides) on lizard. We recorded the first decrease of population at 9 days after treatment. The first decrease of the lizard populations was noted in the phase I (1-12 DAT). We also recorded the first dead or moribund lizards between 9 and 21 days after chemical treatment. The number of death or moribund lizards ranged from 0, 33±0.57 to 4±1 in the plots treated with chlorpyrifos and fenitrothion respectively. The optimum of the efficacy of the pesticides was noted in phase II (15-30 DAT) it was decreased from 76% to 98% with chlorpyrifos and fenitrothion. It was also observed; the chemicals had a delayed effect on the lizard. In the last phase (45-60 days after the treatment) no death or moribund lizards is noted in all plots (treated and untreated).

 

Open Access Original Research Article

Synthesis, Characterization and Photo Catalytic Application of TiO2 Co-doped with Pt+4, Au+4 and S-2

Dina A. Ali, Hussain I. Abdulah, Ramzi R. Alani

Chemical Science International Journal, Page 201-212
DOI: 10.9734/ACSJ/2015/17082

TiO2 singly doped and Co-doped nanoparticles with Pt+4, Au+4, and S-2 ions were prepared by modified Sol-Gel method. These samples characterized by Uv-visible adsorption spectroscopy and showed red-shift in absorption band of TiO2, XRD. showed clear anatase for all modified samples except the Au- TiO2. AFM and SEM were used to study the morphology of the samples. The photocatalytic degradation of Para-Nitrophenol (P-NP) under visible irradiation was examined   for the doped and Co-doped samples. The results shown degradation rates for singly doped in the order of: Au-TiO2 ˃ Au,Pt- TiO2˃ Pt-TiO2 ˃ Au,S-TiO2 ˃ Pt,S-TiO2˃ S-TiO2 ˃ undoped TiO2 sample.

 

Open Access Original Research Article

Synthesis, Characterization and Application of Zn/Al-CO3 ¬for the Removal of Lead Ions

N. Ayawei, A. K. Inengite, D. Wankasi, E. D. Dikio

Chemical Science International Journal, Page 213-226
DOI: 10.9734/ACSJ/2015/18202

 

In the present work, Zn/Al layered double hydroxide of ratio 2:1 was synthesis by co-precipitation method from their nitrate salts and utilized as adsorbent for the removal of lead ions from aqueous solution. The synthesized Zn/Al-CO3 was characterized by SEM, XRD and FTIR. The effect of various parameters such as contact time, initial concentration and variable temperature were investigated. The results show that the adsorption process was depended on contact time rather than temperature and concentration. Studies of the essential thermodynamic parameters shows that the adsorption process was rapid, exothermic and spontaneous and also fitted both Langmuir and Freundlich isotherm. The results of various kinetic models are zero-order kinetics model R2 =1, second-order kinetic model R2 = 0.998 and pseudo-second order kinetics model R2 = 0.999.

 

Open Access Original Research Article

Synthesis, Characterization and Antimicrobial Studies of Oxo Vanadium (IV & V) Complexes with Semi and Thiosemicarbazones of Furan-2-Carbaldehyde and Pyrrole-2-carbaldehyde

Sushil Kumar Sen, Atnafu Guadie Assefa

Chemical Science International Journal, Page 227-235
DOI: 10.9734/ACSJ/2015/15615

Oxovanadium (IV & V) complexes were synthesized from semi- and thiosemicarbazones (L1, HL2, HL3 and H2L4) derived from furan-2-carbaldehyde (L1, HL2) and pyrrole-2-carbaldehyde (HL3, H2L4). The solid isolated complexes were characterized through elemental analysis, UV-Visible spectra, I.R spectra, 1H NMR spectra, mass spectra, magnetic susceptibilities and molar conductance measurements. The isolated complexes except [VO(L2)(OH)2].H2O are paramagnetic in nature and having square pyramidal geometry. Molar conductance values justify the proposed structure with their electrolytic nature. The electronic spectra of these complexes are interpreted by using the Vanquickenborne and MacGlynn ordering xy<xz, yz< x2-y2<z2. The only oxovanadium(V) complex [VO(L2)(OH)2].H2O was synthesized from an alkaline solution of the ligand L2 in aqueous-ethanol and was found to be diamagnetic and distorted octahedral in geometry. The cyclic votammetric studies of the complexes in DMSO were studied to explore the redox behavior of complexes. The free ligands and some of its complexes showed considerable biological activities as antibacterial and as well as possessing antifungal properties.

 

Open Access Original Research Article

A Simple Spectrophotometric Method for the Trace Determination of Iron in Some Real, Environmental, Biological, Food, Pharmaceutical and Soil Samples Using 2-aminophenol

M. Jamaluddin Ahmed, M. Tazul Islam, M. Jahir Hossain, M. Faridul Islam

Chemical Science International Journal, Page 236-253
DOI: 10.9734/ACSJ/2015/16749

A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method is presented for the rapid determination of iron (III) at trace levels using ortho aminophenol or 2-aminophenol (OAP) as a new spectrophotometric reagent (lmax = 402 nm) in slightly acidic (0.0005-0.0015 M H2SO4) aqueous solution. The reaction is instantaneous and absorbance remains stable for over 24 h. The average molar absorption coefficient and Sandell’s sensitivity were found to be 6.65×105 L mol-1 cm-1 and 5 ng cm-2, respectively. Linear calibration graphs were obtained for 0.01-6 mg L-1 of iron with a correlation co-efficient value 0.9998 for Fe-OAP complex. The stoichiometric composition of the chelate is 1:3 (Fe: OAP). The detection limit and quantification of limit of the reaction system were found 1 µg L-1 and 10 µg L-1, respectively. Large excesses of over 50 cations, anions and complexing agents (e.g. tartrate, oxalate, citrate, phosphate, thio-urea, SCN-) do not interfere in the determination. The developed method was successfully used in the determination of iron in several standard reference materials (alloys and steels) as well as in some environmental waters (portable and polluted), biological samples (human blood and urine), food samples (bean, meat, banana, tomato, egg etc.), soil samples, pharmaceutical samples (tablets, capsules etc.), some solution containing both iron (II) and iron (III) and complex synthetic mixtures. The results of the proposed method for biological and food samples were comparable with AAS and were found to be in excellent agreement. The method has high precision and accuracy (s = ±0.01 for 0.5 mg L-1).

 

Open Access Original Research Article

Comparative Determination of Chromium, Iron and Lead in Tamburawa Treated and Raw Water Samples

Kingsley John Igenepo, Ugbe Fabian Audu, Ikudayisi Abiola Victoria, Idris Mustapha Omenesa

Chemical Science International Journal, Page 254-261
DOI: 10.9734/ACSJ/2015/17611

Chemical analysis of raw and treated water from the Tamburawa water treatment plant was conducted twice a week for six consecutive weeks using Spectrophotometric measurement, to determine the level of Cr, Fe, and Pb in the water. The result of the study showed that the concentration of Pb in the raw water (0.023±0.008 mg/L) and treated water sample (0.027±0.011 mg/L) exceeded the WHO permissible limit of 0.01 mg/L for Pb in drinking water. The concentrations of Fe (0.065±0.026 mg/L raw and 0.049±0.024 mg/L treated) and that of Cr (0.017±0.007 mg/L raw and 0.026±0.014 mg/L treated) were found to be within their respective threshold limit of (0.3 mg/L for Fe) and (0.05 mg/L for Cr) respectively set by the World Health Organization (WHO) for drinking water standard. It is concluded that treated Tamburawa water is not potable for drinking with regards to Lead (Pb) because its level exceeded its WHO permissible limit for drinking water standard. Furthermore, the treatment plant needs appraisal and upgrading regulations in order to improve the quality of water being supplied to the Kano metropolis.