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Determination of Ascorbic Acid in Citrus Sinensis and Ananas Comosus Using Poly (3, 4-Ethylenedioxythiophene) Modified Glassy Carbon Electrode
Amanial Haile Reda,
Fisseha Guesh Gebremeskel
Issue:
Volume 4, Issue 1, February 2016
Pages:
1-7
Received:
16 November 2015
Accepted:
26 November 2015
Published:
4 January 2016
Abstract: This study describes the preparation and application of a poly (3, 4-Ethylenedioxythiophene) (PEDOT) modified glassy carbon electrode for ascorbic acid determination in fruit samples by square wave voltammetric method. The PEDOT modified electrode was prepared by electrochemical polymerizing of 3, 4-Ethylenedioxythiophene (EDOT) on a glassy carbon electrode in a non-aqueous medium (0.1 M Tetrabutylammoniumhexafluorophosphate and 0.1 M EDOT in acetonitrile). The best performance of the PEDOT modified electrode in 0.1 M phosphate buffer was obtained at pH 5.0. In addition to this other parameters like electrode thickness, square wave amplitude, and square wave frequency were optimized. Under these conditions, an oxidation potential of ascorbic acid was observed at 395.24 mV versus Ag/AgCl/ reference electrode. The square wave voltammetric study indicated that the PEDOT modified electrode showed a very good electrocatalytic activity by reducing the overpotential by 113.69 mV for ascorbic acid oxidation. The modified electrode also showed a linear response range between 50 and 90μM. The proposed method was checked by determining the recovery of ascorbic acid in two commercially available tablets and provided an excellent recovery (i.e. 99.43 and 93.80%). Finally the method was applied in Orange and Pineapple fruits and 68.11±0.012 and 45.46±0.023 mg ascorbic acid per 100 g of the sample was found in each fruits respectively.
Abstract: This study describes the preparation and application of a poly (3, 4-Ethylenedioxythiophene) (PEDOT) modified glassy carbon electrode for ascorbic acid determination in fruit samples by square wave voltammetric method. The PEDOT modified electrode was prepared by electrochemical polymerizing of 3, 4-Ethylenedioxythiophene (EDOT) on a glassy carbon ...
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Modified Activated Carbon with Zinc Oxide Nanoparticles Produced from Used Tire for Removal of Acid Green 25 from Aqueous Solutions
Farzaneh Jahanbakhsh,
Bahram Ebrahimi
Issue:
Volume 4, Issue 1, February 2016
Pages:
8-13
Received:
27 December 2015
Accepted:
6 January 2016
Published:
15 January 2016
Abstract: Modified activated carbon with zinc oxide nanoparticles (ZnO-n) as carbonaceous adsorbents was prepared by chemical and heat treatment of the used tire in N2 atmosphere. Heat impregnation method was used to modifying the activated carbon with ZnO-n. In fact, Chemical activation, carbonization and heat activation of raw material were toke place in the presence of ZnO-n. The produced carbon sample before modification show specific surface area (SBET) 19.271 m2 g-1 and pour volume (Vp) of 0.273 mL g-1 and after modification the cited parameters were 90.469 m2 g-1 and 0.427 mL g-1 respectively. The SEM images of adsorbent materials later and after impregnation showed excellent differences that lead to increasing the sorption properties related to non-modified activated carbon adsorbent. The prepared samples were studied as adsorbents for removal acid green 25 in aqueous solutions. Amount of adsorbent, dye concentration, time of process and pH of aqueous solutions as effective parameters were optimized. Modified adsorbent showed better results than the non-modified adsorbent and sorption capacity using the Langmuir isotherm was 111.3 and 306.8 mg g-1 for acid green 25 sorption on non-modified and modified adsorbent respectively. This study showed the potential ability of used tire as abundant raw material to production of activated carbon adsorbent and modification of it with Zno-n to increase the sorption properties.
Abstract: Modified activated carbon with zinc oxide nanoparticles (ZnO-n) as carbonaceous adsorbents was prepared by chemical and heat treatment of the used tire in N2 atmosphere. Heat impregnation method was used to modifying the activated carbon with ZnO-n. In fact, Chemical activation, carbonization and heat activation of raw material were toke place in t...
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Determination of Major Oxides Percentages in Portland Cement of Some Sudanese Cement Manufactories
Asrar Adil El-gray,
Faroug Bakheit Mohamed Ahmed
Issue:
Volume 4, Issue 1, February 2016
Pages:
14-17
Received:
2 January 2016
Accepted:
12 January 2016
Published:
16 February 2016
Abstract: In this quality control study, four samples of Portland cement from four Sudanese factories (Atbra, Barbar, Sakhar and Elshamal) were subjected aiming to assess the percentage of mainly oxides in the Portland cement. The study revealed that the percentages of minerals oxides; Calcium oxide, Silicon dioxide, Aluminum oxide, Ferric oxide and Magnesium oxide of the four factories were in the specified limit of quality control according to the American Society for Testing and Materials - Cement (ASTM C150).
Abstract: In this quality control study, four samples of Portland cement from four Sudanese factories (Atbra, Barbar, Sakhar and Elshamal) were subjected aiming to assess the percentage of mainly oxides in the Portland cement. The study revealed that the percentages of minerals oxides; Calcium oxide, Silicon dioxide, Aluminum oxide, Ferric oxide and Magnesiu...
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Environment-Friendly Reduction of Aromatics to Alicyclic Compounds at Room Temperature Using Superactive Calcined Ni-Al Hydrotalcite Catalysts
Ateeq Rahman,
Andre Pelletier,
Mathew Mupa,
Courtie Mahamadi,
Cexton Musekiwa
Issue:
Volume 4, Issue 1, February 2016
Pages:
18-23
Received:
19 December 2015
Accepted:
4 January 2016
Published:
23 February 2016
Abstract: Calcined Ni-Al hydrotalcite (HT) 2: 1, Cat. A, is a superactive catalyst for reduction of substituted aromatics, i. e. toluene, benzene, nitrobenzene, chloro-, bromo-, and iodobenzene to their respective alicyclic products at room temperature in the presence of molecular hydrogen. Cat. A attained higher conversions compared to calcined Ni-Al hydrotalcites with ratios of 2.5: 1, and 3: 1. Calcined Ni-Al HT is a superactive catalyst whereas catalysts Niγ-Al2O3 or Ni-SiO2 with Ni contents of 2%, 5%, and 10% resulted in poor conversions. In these cases, Ni in association with the respective oxide is the active precursor for molecular hydrogen initiation in the reduction of aromatics to alicyclic compounds. The objective is to evalua4e Ni as the best catalyst for aromatic ring reduction to alicylic molecule. Quantitative yield were obtained for all the substrates toluene, benzene, nitrobenzene, chloro-, bromo-, and iodobenzene to their respective cyclohexanes. These results indicate that hydrogenation with reusable Ni-Al HT catalysts is a green sustainable process and atom economy efficient for the production of various alicyclic compounds.
Abstract: Calcined Ni-Al hydrotalcite (HT) 2: 1, Cat. A, is a superactive catalyst for reduction of substituted aromatics, i. e. toluene, benzene, nitrobenzene, chloro-, bromo-, and iodobenzene to their respective alicyclic products at room temperature in the presence of molecular hydrogen. Cat. A attained higher conversions compared to calcined Ni-Al hydrot...
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Removal of Heavy Metals from Pharmaceutical Industrial Wastewater Effluent by Combination of Adsorption and Chemical Precipitation Methods
Tope Babatunde Ibigbami,
Folasegun Anthony Dawodu,
Olayinka John Akinyeye
Issue:
Volume 4, Issue 1, February 2016
Pages:
24-32
Received:
4 January 2016
Accepted:
14 January 2016
Published:
1 March 2016
Abstract: The removal of heavy metals from our environment especially industrial effluents is now shifting from the use of conventional adsorbents to the use of chemical precipitation. The presence of heavy metals in the environment is a major concern because of their toxicity, bioaccumulating tendency, and threat to human life and the environment. The main objective of this research is to study the effectiveness of the combination of hydrogen peroxide and activated bentonite clay in the removal of heavy metal ions from pharmaceutical industrial effluent. About 13.790 mg/l of Fe, 1.650 mg/l of Zn and 2.000 mg/l of Ni were detected in the digested sample and batch removal of heavy metals such as Fe, Zn and Ni from industrial wastewater effluent under different experimental conditions using hydrogen peroxide as precipitating agent in combination with activated bentonite clay as adsorbent. Appreciable differences in the level of heavy metals concentration were observed based on pH effect. The result shows higher effectiveness relatives to other treatments formulated for the effluent treatment such as Alum precipitation effect, effect of hydrogen peroxide concentration dose, contact time effect and temperature effect. Removal of heavy metals in effluent was optimum at pH 10 for zinc (Zn) and nickel (Ni) and at pH 8 for iron (Fe), at temperature of 50°C, 0.75% hydrogen peroxide concentration dose and 100 mins holding time, reducing the amounts from 13.790 to 1.436 mg/l of Fe, while 1.650 to 0.127 mg/l of Zn and 2.000 to 0.115 mg/l of Ni respectively. The percentage differences in concentration for the heavy metals removal in industrial wastewater are as follows: Fe (89.58%), Zn (92.30%) and Ni (94.22%). The result showed high level of Zn and Ni generated from this pharmaceutical industry is above 1 mg/l FEPA and WHO standard but only Fe showed low level concentration compared to 20 mg/l FEPA and WHO standard in this study. This study reveals the need for enforcing adequate effluent treatment methods before their discharge to surface water to reduce their potential environmental hazards.
Abstract: The removal of heavy metals from our environment especially industrial effluents is now shifting from the use of conventional adsorbents to the use of chemical precipitation. The presence of heavy metals in the environment is a major concern because of their toxicity, bioaccumulating tendency, and threat to human life and the environment. The main ...
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