African Journal of Pure and Applied Chemistry最新文献

{"title":"The potential of binary blended geopolymer binder containing Ijero-Ekiti calcined kaolin clay and ground waste window glass","authors":"M. B. Ogundiran, Festus Abodunde Winjobi","doi":"10.5897/AJPAC2015.0640","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0640","url":null,"abstract":"The aim of this study was to investigate alkaline reactivity potentials of calcined clay and ground waste window glass with NaOH/Na2SiO3 solution to form geopolymer, an inorganic binder. A calcined clay (CC) sourced from Ijero-Ekiti, Nigeria, was replaced by various proportions (0, 25, 50 and 75%) of ground waste window glass (GWWG) and subjected to alkaline activation by NaOH/Na2SiO3 solution. X-ray florescence (XRF) and Fourier Transform Infrared (FTIR) spectroscopy were applied to characterise the materials and the resulting geopolymers. The XRF results revealed the main oxides of Ijero-Ekiti clay as SiO2 and Al2O3 and for GWWG as SiO2 and Na2O. The FTIR results confirm the clay as kaolin clay which is suitable for geopolymer synthesis. The synthesised geopolymer binders were cured at room temperature for 7, 14, 21 and 28 days. Their compressive strengths, dry density and water absorption were measured. Geopolymers with ground waste window glass (GWWG) indicated higher strengths at both early and late curing times. The final 28-day compressive strength values of GWWG-CC-based geopolymers observed was in the range of 17.3±0.6 to 23.1±0.7 MPa compared with 11.6±0.4 to 14.5±1.4 MPa for 100% CC-geopolymers. Calcined clay replacement up to 75% glass yielded the highest strength. Addition of window waste glass enhanced both early and late strength gain of the geopolymers and improved physical properties. Therefore, GWWG-CC-geopolymers could serve as potential binders in making green construction and building materials. \u0000 \u0000   \u0000 \u0000 Key words: Ijero-Ekiti kaolin clay, waste window glass, recycling, clay-waste-glass-geopolymer, compressive strength development.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"9 1","pages":"159-166"},"PeriodicalIF":0.0,"publicationDate":"2015-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82583676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study of the morphology and optical properties of electro polished steel in the presence of Vitamin-C","authors":"F. Abouzeid","doi":"10.5897/AJPAC2015.0631","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0631","url":null,"abstract":"The studies of steel electrochemical polishing Electropolishing (EP) in orthophoshoric acid were performed by potentiodynamic polarization. Electropolishing was conducted in solution containing Vitamin C. Addition of Vitamin C to electropolishing solution results in a lower limiting current. Vitamin C concentration influence on electropolishing process and surface texture (AFM, SEM) and UV-VIS-NIR Spectroscopy was established. The results show that by increasing Vitamin C concentration from 2 × 10-5 to 5 × 10-5 M, roughness and reflectance of steel specimens decrease/increase respectively. The opposite trend is seen when the concentration increases to 10 × 10-5 M. The roughness of steel specimen before electropolishing is 236.7 nm and it will decrease to 140 nm by electropolishing in the presence of 5 × 10-5 M Vitamin C. A similar trend is also seen in reflection. The SEM study confirms that low and moderate concentration of Vitamin C was effective to enhance levelling and brightness more than higher concentrations. \u0000 \u0000   \u0000 \u0000 Key words: Steel, electropolishing, Vitamin C, scanning electron microscope (SEM), atomic force microscope (AFM), reflectance.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"67 1","pages":"135-145"},"PeriodicalIF":0.0,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86085759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unexpected mixed valence iron(II, III) 3-oxo furfuryl complex with wheel motif isolated when preparing iron(II) arene complexes","authors":"Roger Mafua","doi":"10.5897/AJPAC2015.0621","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0621","url":null,"abstract":"A series of new compounds including 2-({[(4-(propoan-2-yl)benzyl]Oxy}methyl)tetrahydrofuran ligand were tested in order to link auxiliary and labile ligands to iron arene complexes. The given reaction of benzyletherfurane ligand with Fe (II) sources resulted to the isolation of unexpected mixed valence µ3-oxo-Fe6IIFeIII compound, which has been fully characterized by x-ray crystallography. The resulting complex differs from the similar compound known in the literature. \u0000 \u0000   \u0000 \u0000 Key words: Mixed valence complex, heptanuclear Fe(II,III), wheel motif structure, dangling spatial orientation of furfuryl ligand, 2-({[4-(propoan-2-yl)benzyl]Oxy}methyl)tetrahydrofuran, single crystal.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"9 1","pages":"113-124"},"PeriodicalIF":0.0,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87729586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibitive and adsorptive effect of Parinari polyandra on mild steel corrosion in aqueous sulphuric acid","authors":"F. Awe, S. Idris, M. Abdulwahab, Emeka Emanuel Oguzie","doi":"10.5897/AJPAC2015.0630","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0630","url":null,"abstract":"The inhibition of mild steel corrosion in 0.5 M sulphuric acid solution by ethanol extracts of Parinari polyandra as an eco-friendly inhibitor was studied at different temperatures by weight loss technique and linear polarization. The test plant extracts has a promising inhibitory action against corrosion of mild steel in the sulphuric acid media. The inhibition efficiencies increase with a corresponding increase in the concentration of the inhibitor. The adsorption of the inhibitor on mild steel surface is exothermic, spontaneous and is best described by Freundlich and Temkim adsorption models. Calculated values of activation energy, enthalpy of activation, entropy of activation, free energy of adsorption and the trend in the variation of inhibition efficiency with temperature, the mechanism of the process is by physical adsorption. Ethanol extract of Parinari polyandra is a good adsorption inhibitor for the corrosion of mild steel in sulphuric acid. Tafel polarization analyses indicate that the studied plant extract is a mixed type inhibitor. \u0000 \u0000   \u0000 \u0000 Key words: Isotherm, polarization, adsorption, inhibitor, Parinari polyandra.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"12 1","pages":"125-134"},"PeriodicalIF":0.0,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85529239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of anti-oxidant properties in essential oil and solvent extracts from Tagetes minuta","authors":"Kyarimpa Christine, I. N. Omolo, J. Kabasa, C. Nagawa, J. Wasswa, C. R. Kikawa","doi":"10.5897/AJPAC2015.0616","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0616","url":null,"abstract":"Synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are toxic and carcinogenic, thus they induce DNA damage. This calls for the need to find alternative antioxidants from natural products. Tagetes minuta (Asteraceae) is an annual herb that belongs to the Asteraceae family. It is used in common medicine and grows in temperate regions of South America, some parts of Africa and Asia. Essential oil from T. minuta was obtained by hydrodistillation while solvent extracts were obtained using ethyl acetate and methanol. Antioxidative compounds of T. minuta were isolated both from the Ethyl acetate extract and the essential oil. It was done by determining the scavenging activity using 2,2-diphenyl-1-picrylhaydrazyl free radical (DPPH) using thin layer chromatography (TLC). The active compounds were tested quantitatively for their radical scavenging activity using the U-1100 UV-VIS Spectrophotometer. The active fractions were isolated using TLC and High performance liquid chromatography (HPLC) and later detected using both Gas chromatography mass spectrometry (GC-MS) and Nuclear magnetic resonance (NMR). One pure active compound was obtained from the ethylacetate extract (neophytadene) by a combintion of GC-MS and NMR. The essential oil contained a number of compounds among which are trans-ocimen 15.90%, I-verbanone 15% of limonene 8.02%, tegetone 3.56%, and 2-pinen-4-one 7.84%.              Key words: Antioxidant activity, essential oil, 2,2-diphenyl-1-picrylhaydrazyl free radical (DPPH), Tagetes minuta.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"10 1","pages":"98-104"},"PeriodicalIF":0.0,"publicationDate":"2015-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85937829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accessing the potential of Lonchocarpus laxiflorus roots (LLR) plant biomass to remove Cadmium (II) ions from aqueous solutions: Equilibrium and kinetic studies","authors":"H Santuraki A, A Muazu A","doi":"10.5897/AJPAC2015.0620","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0620","url":null,"abstract":"The potential of Lonchocarpus laxiflorus roots (LLR) for the removal of Cd (II) ions from aqueous solutions has been investigated. The adsorption of Cd (II) ions was found to be affected by solution pH, contact time, adsorbent dosage, initial metal ion concentration, and temperature. The equilibrium was analysed using Langmuir and Freundlich isotherm models. The data was found to have a closer correlation with the Lamgmur isotherm as evidenced by a higher correlation coefficient (R2). The adsorption capacity for L. laxiflorus was found to be 19.35 mg g-1 and the removal efficiency of the LLR was found to be 98% under optimized conditions. The kinetics data was also subjected to pseudo-first-order and the pseudo-second-order kinetic models. The data could be explained better using the pseudo-second-order kinetic model. The selected biosorbent has been analyzed by FT-IR for identification of contributing functional groups, x-ray powder diffraction (XRD) for its structural properties and scanning electron microscope (SEM) for the structural morphology analysis. \u0000 \u0000   \u0000 \u0000 Key words: Biosorption, cadmium, isotherms, kinetics, Lonchocarpus laxiflorus.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"37 1","pages":"105-112"},"PeriodicalIF":0.0,"publicationDate":"2015-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74039614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phytochemical composition, antioxidant and anti-nutritional properties of root-bark and leaf methanol extracts of Senna alata L. grown in Nigeria","authors":"I. Abubakar, A. Mann, J. Mathew","doi":"10.5897/AJPAC2015.0622","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0622","url":null,"abstract":"Senna alata L. has been ethnobotanically used extensively in traditional medicines for the treatment of a variety of diseases such as skin problems, arthritis, HBP (high blood pressure), and laxative or purgative. The phytochemical, anti-nutritive and antioxidant activities of the leaf and root bark of Senna alata L. grown in Bida Niger State, Nigeria were determined using standard analytical methods. Phytochemical screening of the flower and seed of the plant revealed the presence of flavonoids, phenols, saponins, tannins, alkaloid and anthraquinone. Steroid and cardiac glycosides, were slightly present, while resins were absent. The metabolites present were quantitatively determined with alkaloid contents of 14.09±0.50 and 15.89±0.72, saponin 40.57±0.57 and 33.02±0.07, flavonoid 42.28±0.90 and 36.52±0.38, tannin 59.48±0.50 and 44.38±0.72, and phenol 7.84±0.49 and 9.91±0.68 mg/100 g for leaf and root bark respectively. These results confirm that the metabolites obtained from the two parts of this plant were within the range of toxicity levels according to World Health Organization safe limits. The results of anti-nutritional factors revealed oxalate contents of 7.84±0.74 and 9.91±0.62, cyanide content 13.04±0.09 and 21.69±0.11 and phytate content 15.07±0.58 and 12.44±0.31 mg/100 g for leaf and root bark respectively. The values of anti-nutritional factors obtained from this work show that they may not pose any effects based on their toxicity levels and as recommended by World Health Organization. The major components of the chemical compounds deduced from GC/MS for the two parts of this plant investigated revealed the presence of α-d-mannofuranoside (53.35%), oleic acid (12.30%), β-d-glucopyranoside (12.59%), β-d-mannofuranoside (22.41%), n-hexadecenoic acid (5.73%), 1,2,3- propanetriol (21.54%), α-d-glucopyranoside (16.41%) and oleic acid (14.65%). Thus, if properly domesticated and produced in commercial quantities, this plant will serve as a source of bioactive agents for pharmaceuticals. \u0000 \u0000   \u0000 \u0000 Key words: Antioxidant, phytochemical, anti-nutritional, leaf, root bark and Senna alata.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"1 1","pages":"91-97"},"PeriodicalIF":0.0,"publicationDate":"2015-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83614298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of phenylethyl alcohol by reversed-phase high-performance liquid chromatography (RP-HPLC) in Budesonide nasal spray","authors":"R. Hosseini, F. Naderi, S. Nasrollahi","doi":"10.5897/AJPAC2015.0619","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0619","url":null,"abstract":"Phenylethyl alcohol is used as an antimicrobial preservative in many pharmaceutical products, especially nasal sprays. A simple and accurate reverse phase high performance liquid chromatographic method was developed to assay of phenylethyl alcohol in budesonide nasal spray preparations. A waters C18 symmetry column chromatographic system (150 × 4.6 mm, 5 µm particle size) was performed with a 50:50 (%V/V) mixture of water and acetonitrile as a mobile phase. The detection of the phenylethyl alcohol was carried out at 220 nm and flow rate was employed 1.0 ml/min. The retention time of phenylethyl alcohol was about 2.8 min. Linearity was established in the concentration range of 173.28 to 259.92 mg/ml (80 to 120% of the target concentration), with a regression coefficient of 0.9991. Specificity was tested in the presence of placebo; no interference was detected at the retention time of phenylethyl alcohol. The results of the analysis were validated statistically and recovery percentage studies confirmed the accuracy and precision of the proposed method. \u0000 \u0000   \u0000 \u0000 Key words: Phenylethyl alcohol, budesonide, nasal spray, reversed-phase high-performance liquid chromatography (RP-HPLC), preservative.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"31 1","pages":"81-90"},"PeriodicalIF":0.0,"publicationDate":"2015-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84693847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidation of acha (Digitaria exilis) starch using 3.5% active chlorine sodium hypochlorite","authors":"S. Isah, A. Oshodi, V. N. Atasie","doi":"10.5897/AJPAC2015.0617","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0617","url":null,"abstract":"Acha (Digitaria exilis) starch was chemically modified using sodium hypochlorite (3.5% active chlorine) as oxidative agent. The physicochemical properties of the native acha starch and oxidized derivative were investigated. Oxidation improved the water and oil absorption capacity of the native acha starch and also the emulsion capacity was significantly improved. The bulk density, foam capacity and solubility reduced upon oxidation. The granule morphologies investigated using scanning electron microscopy showed significant difference in the ratio of crystalline and amorphous regions. However, oxidation of native acha starch did not affect the shape, appearance and structural arrangement of the starch granules. The granules were polygonal in shape with size range of 6 to 8.57 µm. The infra spectra showed additional band at 3600 cm-1 for the oxidized derivative indicating hydroxyl group stretching vibration of carboxylic acid. This indicates that the oxidation of native acha starch was successfully carried out. Improved physicochemical properties impacted upon oxidative modification is quite desirable in impacting greater stability and less retrogradation and seneresis of the native acha starch. Thus, oxidized acha starch will find suitable applications in food, pharmaceutical, paper and textile industries as good dispersants, emulsifying agent, surface sizing, adhensive, disintegrants, excipients and preparation of biopolymer based flocculants. \u0000 \u0000   \u0000 \u0000 Key words: Modified starch, starch oxidation, physicochemical properties, scanning electron microscopy, starch granules.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"95 2 1","pages":"65-70"},"PeriodicalIF":0.0,"publicationDate":"2015-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78029321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reversal of plasticity of acid leached kaolinitic clays from Mukurwe-ini","authors":"D. Andala, W. Maina","doi":"10.5897/AJPAC2015.0610","DOIUrl":"https://doi.org/10.5897/AJPAC2015.0610","url":null,"abstract":"This study aimed at finding out whether the property of plasticity of acid leached clays can be reversed by treatment with a suitable base. Studies were carried out on representative samples, which were taken from iron bearing clays from Mukurwe-ini, Nyeri County in Kenya (Latitude 00°34´00´´S, Longitude 37°03´00´´E). Characterization of the clay was done in its natural form, and after acid treatment, to determine its mineralogical and chemical composition. Natural clay was refluxed with sulphuric and hydrochloric acids of different concentrations at 100 and 200°C for 2 h followed by thorough washing with distilled water to remove the acid matrix. Atomic absorption spectroscopy, X-ray fluorescence spectroscopy, and X-ray diffraction, analysis techniques were used to determine the physico-chemical characteristics of natural and acid leached clays. The results indicate that SiO2, Al2O3, and Fe2O3 are the major components of Mukurwe-ini clay, MgO, CaO, K2O, TiO2, MnO, and Na2O are present in trace amounts. XRD characterization shows that Mukurwe-ini clays consist primarily of quartz, kaolinite, albite, and microcline minerals. Iron content was drastically reduced in the acid washed samples and X-ray diffraction (XRD) mineralogical analysis of base acid-activated clays showed enhanced levels of the mineral kaolinite in comparison to acid-activated clays (5.3 to 15.7%) a clear indication that the natural properties of the acid washed clay were restored by base treatment of acid washed samples. The Atterberg limits of the base treated samples closely compared with those of the natural clays. \u0000 \u0000   \u0000 \u0000 Key words: Clay minerals, Atterberg limits, and plasticity.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"52 1","pages":"71-80"},"PeriodicalIF":0.0,"publicationDate":"2015-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90540930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}