Levels of Selected Heavy Metals in Wheat Flour on the Ghanaian Market: A Determination by Atomic Absorption Spectrometry
E. D. Doe,
A. K. Awua,
O. K. Gyamfi,
N. O. Bentil
Issue:
Volume 1, Issue 2, June 2013
Pages:
17-21
Received:
9 May 2013
Published:
10 June 2013
Abstract: Wheat flour is an important source of nutrient and as such is widely consumed in most part of the world, as bread and other pastries. Due to its high consumption, the presence of heavy metal at high concentration would be a significant health risk. Based on the soil in which the wheat was grown and the milling technology employed in making the flour, the heavy metal content of wheat flour varies. In analyzing heavy metal content of flour on the Ghanaian market, (one made in Ghana and another made in Turkey) an atomic absorption spectrophotometric analysis of milestone acid digested flour was used with the appropriate standards. With a 9% - 100.4% recovery rate, Fe, Zn, Mn, Cd, Pb were detected at varying concentrations in both flour brands, while Co, Ni, Cu, Cr, As, Hg were below detection limits. The levels of the nutritionally important elements such as Fe and Zn would be beneficial to human health, while those of the toxic element present are not likely to pose any health risk to consumers of this flour.
Abstract: Wheat flour is an important source of nutrient and as such is widely consumed in most part of the world, as bread and other pastries. Due to its high consumption, the presence of heavy metal at high concentration would be a significant health risk. Based on the soil in which the wheat was grown and the milling technology employed in making the flou...
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Central Composite Experimental Design Applied to the Catalytic Carbon-Sulfur Bond Formation by Fluorapatite Catalyst
Younes Abrouki,
Abdelkader Anouzla,
Hayat Loukili,
Rabiaâ Lotfi,
Ahmed Rayadh,
My Abdellah Bahlaoui,
Saı̈d Sebti,
Driss Zakarya,
Mohamed Zahouily
Issue:
Volume 1, Issue 2, June 2013
Pages:
22-27
Received:
28 May 2013
Published:
30 June 2013
Abstract: The aim of this study was to apply experimental design in the optimization of the thia-Michael addition reaction between chalcone derivatives and mercaptans catalyzed by Fluorapatite catalyst (FAP). The central composite design was used to design an experimental program to provide data to model the effects of various factors on reaction yield (Y). The variables chosen were catalyst weight (X1), reaction time (X2) and solvent volume (X3). The mathematical relationship of reaction yield on the three significant independent variables can be approximated by a nonlinear polynomial model. Predicted values were found to be in good agreement with experimental values. The optimum reaction conditions (x1= 350 mg, x2= 30 min and x3= 2 mL) for reaction model (chalcone and thiophenol) obtained by response surface were applied to other substrates. This study has shown that central composite design could efficiently be applied for the modeling of catalytic carbon-sulfur bond formation by FAP catalyst under mild reaction condition with high yield, and it is an economical way of obtaining the maximum amount of information with the fewest number of experiments.
Abstract: The aim of this study was to apply experimental design in the optimization of the thia-Michael addition reaction between chalcone derivatives and mercaptans catalyzed by Fluorapatite catalyst (FAP). The central composite design was used to design an experimental program to provide data to model the effects of various factors on reaction yield (Y). ...
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Preparation, Characterization, and Catalytic Studies of Iron and Cobalt Complexes Supported by ONNO – Tetradentate Schiff-Base Ligands
Alekha Kumar Sutar,
Yasobanta Das,
Sasmita Pattanaik,
Anita Routaray,
Prasanta Rath,
Tungabidya Maharana
Issue:
Volume 1, Issue 2, June 2013
Pages:
28-36
Received:
25 May 2013
Published:
10 July 2013
Abstract: The free and polymer anchored complexes of iron and cobalt [3-MHBdMBn-M and P-3-MHBdMBn-M], supported by ONNO-tetradentate Schiff-base ligands are prepared by the reactions of metal solution with one molar equivalent of unsupported 3-MHBdMBn (N, N'-bis (2-hydroxy-3-methylbenzaldehyde) 4-Methylbenzene-1,2-diamine) or polymer supported (P-3-MHBdMBn) Schiff-base ligands in methanol. The structural study reveals that iron(III) complex of 3-MHBdMBn Schiff base is octahedral in geometry, whereas, cobalt(II) ions complexes is square planar. Complexation of metal ions increased the thermal stability of 3-MHBdMBn Schiff base. The catalytic activities of metal complexes towards the oxidation of phenol are investigated in the presence of hydrogen peroxide. Experimental results indicate that the reactivity of P-3-MHBdMBn-M is dramatically affected by the polymer support over 3-MHBdMBn-M and iron complexes have greater activity than the cobalt analogue.
Abstract: The free and polymer anchored complexes of iron and cobalt [3-MHBdMBn-M and P-3-MHBdMBn-M], supported by ONNO-tetradentate Schiff-base ligands are prepared by the reactions of metal solution with one molar equivalent of unsupported 3-MHBdMBn (N, N'-bis (2-hydroxy-3-methylbenzaldehyde) 4-Methylbenzene-1,2-diamine) or polymer supported (P-3-MHBdMBn) ...
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