8 research outputs found

    Green Synthetic Methods for a Schiff Base from 2-Aminopyridine and 4-Ethoxybenzaldehyde

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    The novel Schiff base was acquired from the reaction between 2-aminopyridine and 4-ethoxybenzaldehyde using three (3) techniques; refluxing in ethanol for 2 hours, stirring in ethanol and an ethanol-water (1:1) mixture at room temperature for an hour. The synthesis of the 2-aminopyridine-4-ethoxybenzaldehyde Schiff base produced dark yellow crystals with melting point range of 95-97oC. The reaction in ethanol under reflux produced the highest yield of 88.2% while the reaction in ethanol and ethanol-water (1:1 v/v) mixture at room temperature gave 69.2% and 43.5% yield of the compound respectively. The IR spectrum showed the following bands; 1681cm-1 (C=N), 1595cm-1 (aromatic C=C stretch), 2981cm-1 (aromatic C-H stretch), 1509cm-1 (aromatic C=N stretch), 1155cm-1 (aliphatic C-C stretch), 1036 (aromatic C-O stretch), 2825 (aliphatic C-H stretch). The 13C NMR spectrum showed the following chemical shifts (δppm); 158.48 (C=N, imino), 154.98 and 150.18 (C-N of aromatic pyridine moiety), 121.44 – 137.53 (aromatic carbons), 158.68 (aromatic C-O), 63.88 (aliphatic C-O), 15.22 (aliphatic C). The 1H NMR spectral data (δppm) for the compound gave the following results; 7.06-7.91, m (8H) (Ar-H), 9.71, s (1H) (HC=N-), 4.10, q (2H) and 1.32, t (3H) (OCH2CH3). The spectral data was in agreement to the predicted structure of the Schiff base

    The Persistence of Herbicide Residues in Fadama and Upland Soils in Plateau State, Nigeria

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    Fadama and upland soil in Plateau State, Nigeria were monitored for the residues of five herbicides widely used for farming within the areas under investigation from June 2010 to June 2012. The average concentration in mg/kg of the residues in the soils were; atrazine (0.123), 2,4-D (0.013), paraquat (0.020), oxadiazon (0.100) and pendimethalin (0.020) for fadama soils. While the concentration of the atrazine, 2,4-D, paraquat, oxadiazon and pendimethalin in upland soils were 0.180, 0.023, 0.030, 0.0130 and 0.010 mg/kg respectively, suggesting the herbicide residues persist at considerably high concentration. Physicochemical factors such as pH, Low Organic matter and textural characteristics of the soils were the factors identified to contribute to the persistence of the herbicides. Other factors like microbial activities were also suggested to play significant roles in the degradation or the persistence of the herbicide residues. The distributions of the residues were monitored seasonally over a period of time within the study area. This was sampled for laboratory analysis during the farming seasons covering planting to harvesting time where most of these herbicides and other chemical farm inputs are still believed to be active in the soils within the study area. The herbicides under investigation were observed to persist more in fadama soils which is characterized by high water holding capacity and low organic matter content.   Keywords: Persistence, herbicide residues, fadama, upland, soil

    Structural Modification of Cellulosic Fabric via Esterification Using Balanites aegyptiaca Seed Oil

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    Cellulose fabrics were esterified by using varying volume of Balanites aegyptiaca seed oil. X-ray diffraction analysis was carried on the esterified fabrics and unesterified fabric. The crystallographs of all esterified fabrics gave almost the same profile different from that of control fabric. The control fabric gave a sharp single peak at 24.033º diffractometer angle. Esterified fabrics gave a slightly broad split peaks at lower diffractometer angles which ranged from 20.080 – 22.690º, suggesting that there was structural modification of cellulose. The inter-atomic distance (d-spacing) for control fabric was 3.7027 Å. There was increase in d-spacing which ranged from 3.9192 – 4.4216 Å for esterified fabric. The peak width increased from 1.5º (control) to range of 1.6 – 2.8º (esterified) fabrics. The peaks intensity increased from 5489 (control) to highest value (7798) for 30 cm3 of oil esterified fabric. The crystallite size reduced from 9.9 nm (control) to a maximum value (9.2 nm) for 40 cm3 and to minimum value (5.3 nm) for 10 cm3 oil esterified fabrics. The percentage crystallinity reduced from 65% (control) to a range of 62–63% for esterified fabrics. From the results obtained, it can be concluded that reduction in crystallite size, increase in d-spacing, intensity and peak width were due to the presence of a bulky ester group in the cellulose chain; this may also have led to the observed decrease in percentage crystallinity of the esterified fabrics. This structural modification is expected to have direct consequences on the physical and mechanical properties as well as the dyeing properties of the esterified fabrics

    Structural Modification of Cellulosic Fabric via Esterification Using Jatropha curcas Seed Oil

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    This paper presents the results of x-ray diffraction of a cellulose fabric treated with oils extracted from the seed of Jatropha curcas; the oils were extracted with hexane under reflux while the fabric was purified by scouring, bleaching and mercerization to remove dirt and coloring matter in order to make it suitable for esterification. Apart from the controlled sample which was un-esterified, other samples of the same fabric were treated with different volume and concentration of the oil under the same temperature. The x-ray diffraction analysis carried out on all samples showed that while the control sample had a sharp single peak at 24.033° all the esterified samples showed broad split peaks at angles ranging from 20.308o to 22.809o; also while the control sample had inter-atomic (or d-spacing) of 3.702 Å those of the treated sample ranged from 3.8984 Å to 4.3727 Å, in addition to these the peak width increased from 1.5o in the control sample to between 1.9o to 2.8o in the treated samples. Other significant results showed that the peaks intensity increased from 5489 to highest value 8313 in the sample treated with 20 cm3 of oil. Crystallinity was observed to reduce from 65% in the control to about 63% for esterified fabrics samples and lastly, crystallite size reduced from 9.9 nm to between 5.3 nm to 7.7 nm. The observed structural modifications in treated fabric may have direct influence on the physical, mechanical properties as well as dye-ability of the treated samples. The result of water Imbibition also revealed structural modification as there was a decrease in the amount of water imbibed by esterified fabric, indicating a reduction in the number of OH groups in the new cellulose derivative as revealed in the x – ray analysis. Hence the esterified fabric will be less susceptible to microbial attack during storage

    Extraction of “Quercetin-Rich” Red Onion Skin with Acetone and Chemical Modification using Aromatic Diazonium Salts

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    The extraction of “quercetin-rich” red onion skin (red onion skin extract [ROSE]) using acetone and chemical modification with aromatic diazonium salts of aniline (AmROSE), 2-aminophenol (APmROSE), and 2-aminobenzoic acid (ABmROSE) were carried out in this study. The effects of the particle diameter of red onion skin (ROS), volume of the solvent, and percentage of acetone in the solvent mixture on the extraction yield were investigated. The solubility, color, melting point, and functional groups present in ROSE before and after modification were also analyzed. The extraction of ROS using an aqueous solvent of 50% acetone gave the highest percentage extraction yield. In addition to the C=O, OH, C-O-C, and C-O-H functional groups that were present in both unmodified ROSE (UROSE) and modified ROSE, Infrared spectra results revealed that all the modifications (AmROSE, APmROSE, and ABmROSE) showed the presence of N=N and C-N of aromatic azo compounds at 1512–1496 and 1288–1256 cm−1, respectively. The three modifications were also found to be more soluble than UROSE in all the solvents. The melting point of UROSE and its modifications was within the range of 78 °C–105 °C, which was lower than that of commercial quercetin dehydrate P-Q (300 °C–310 °C)

    <b style="">Antifungal activity of extracts of some <i style="">Cassia</i>, <i style="">Detarium </i>and <i style="">Ziziphus </i>species against dermatophytes</b> <b style=""> </b>

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    357-360The methanol extracts of Cassia occidentalis Linn., C. singuena (Del.) Lack, C. tora Linn., Detarium microcarpum Guill. &amp; Perr., Ziziphus abyssinica (Hochst ex A. Rich) Fiori, Z. mauritiana Lam., Z. mucronata Willd. and Z. spina-christi Willd. found in Bauchi State, Nigeria, showed antifungal activity when tested by the agar diffusion method against dermatophytes, viz.Trichophyton rubrum, T. mentagaphytes, Microsporum canis and Aspergillus fumigatus.</i
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