Browsing by Author "Olatunji, G.A."
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Item CHROMATOGRAPHIC SEPARATION AND SPECTRO-ANALYTICAL CHARACTERIZATION OF A NATURAL AFRICAN MINERAL DYE(2007) Adebayo, G.B.; Adekola, F.A.; Olatunji, G.A.Chromatographic fractionation and spectroscopic characterization of a natural African mineral dye have been carried out. The chromatographic separation of the dyes made use of column and thin layer chromatographic techniques. Some physicochemical properties of thedye including solubility in polar and non-polar solvents, pH, ash and organic contents were determined. The spectro-analytical techniques used for characterization included energy dispersive X-ray fluorescence (EDXRF), X-ray diffractometry (XRD), Optical microscopy, infrared (IR) and UV-VIS spectroscopy. Four different fractions having colours yellow, grey, orange and purple were obtained from the chromatographic separation. All the fractions were found to contain aromatic nucleus based on IR and UV-VIS spectroscopic data. Other functional groups detected are Ar-NH2, -CONH2, C=C, C-C and metal-carbon chelate rings. The presence of aromatic amine in the dye provides strong evidence for its use as hair dye. The dye was found to be soluble in both aqueous and non-aqueous solvents. The pH of the dye’s aqueous solution was found to be 8.6, and the ash and organic content of the raw dye were 49% and 51% respectively. The XRF revealed that the dye contains twenty elements with concentrations ranging from major to ultratrace levels. The XRD also showed that the sample contains about forty-six mineral phases which include both inorganic and organic components. The maximum absorption wavelength (•max) in UV-VIS of the aqueous solution was found to be 464 nm. The optical microscopic investigation gave indication that the dyes are likely to be of the marine origin.Item The Effect of Two African Mineral Dyes on the Activity of Alkaline Phosphatase in the Skin and Serum of Albino Rats(2006-09) Adebayo, G.B.; Sunmonu, T.O.; Adekola, F.A.; Olatunji, G.A.The effect of two African mineral dyes Yombo tumtum (YT) and Yombo fita (YF) on the activity of alkaline phosphatase (ALP) in the skin and serum of albino rats was investigated. The chemical analyses of the dyes were first carried out using solubility test, pH determination and X-ray fluorescence (XRF) elemental analysis. Six different concentrations (0.05, 0.15, 0.25, 0.5, 0.75 and 1.00%) of each dye were prepared using hydrogen peroxide as solvent. A total of 70 albino rats (Rattus norvegicus) were used for the study. The rats were grouped into 14 of 5 rats and were maintained on commercial feed for a period of 30 days, during which the experiment lasted. Group I served as the first control and the animals had distilled water applied on their heads. Group 2 which served as the second control contained rats on whose heads were applied the dissolving solvent i.e. hydrogen peroxide. Rats in group 3 to 8 had the various concentrations of YT (black) dye applied on their heads, while those in groups 9 to 14 had the various prepared concentrations of YF (white) dye applied on their heads. At the end of the experiment, blood samples were collected and portion of the head skin where the dyes were applied was cut. The activity of ALP was thereafter determined in the serum and skin of the experimental animals. The results revealed a significant decrease (p<0.05) in the activity of ALP as the concentration of the dye increased in both the serum and skin @JASEM.Item Effect of white African mineral hair dye on the activities of phosphatases and malondialdehyde level in selected tissues of albino rats(2005-09) Adebayo, G.B.; Sunmonu, T.O.; Adekola, F.A.; Olatunji, G.A.The effect of white African mineral dye Yombofita (YF) on the activities of alkaline phosphatase (ALP), acid phosphatase (ACP) and malondialdehyde (MDA) levels in the skin, liver, kidney and serum of albino rats was investigated. The chemical analysis of the dye was first carried out using solubility test, pH determination and X-ray fluorescence (XRF) elemental analysis. Six differentconcentrations (0.05, 0.15, 0.25, 0.5, 0.75 and 1.00%) of the dye were prepared using hydrogen peroxide (30 volume) as solvent. A total of 80 albino rats (Rattus norvegicus) were used for the study. The rats were divided into 8 groups of 10 each and were maintained on commercial feed for the period of the experiment i.e. 30 days. In group 1, the control group, the animals were applied distilled water on their heads, whereas in group 2 the vehicle i.e. hydrogen peroxide was applied. In groups 3 to 8 various concentrations of YF (white) dye ranging from 0.05, 0.15, 0.25, 0.5, 0.75 to 1.00% was applied respectively. At the end of the experiment, blood samples were collected and portions of the selected tissues were excised for the determination of ALP and ACP activities. The MDA level was also determined in the skin of experimental animals. The results revealed a significant decrease (p<0.05) with increasing concentration of the dye in the activities of ALP and ACP in the kidney and skin but not in the liver while the level of MDA in the skin increased significantly (p< 0.05) with increasing concentration of the dye.Item Improving Jatropha curcas Linneaus seed oil alkyd resins(Elsevier, 2012) Odetoye, T.E; Ogunniyi, D.S.; Olatunji, G.A.The Jatropha curcas Linnaeus (JCL) oil was extracted, refined and modified through epoxidation, hydroxylation and dehydration steps in order to increase the degree of unsaturation in the oil alkyl chain. The modified oil was subsequently used for alkyd resin preparation (50% oil formulation) using a two-stage alcoholysis-polyesterification method. Drying performances of white gloss paints formulated from the desaturated oil alkyd, considering a pigment-volume concentration of 20.67% gave improved results. Blending of the improved 50% JCL oil alkyd with acrylic further enhanced the drying properties and compare well with commercial standards. White gloss paint formulated from the improved JCL alkyd–acrylic blends (1:3) dried hard within 2 h at an outdoor temperature of 37 °C ± 2.Item Improving Jatropha curcas Linneaus seed oil alkyd resins(Wiley, 2012) Odetoye, T.E; Ogunniyi, D.S.; Olatunji, G.A.The Jatropha curcas Linnaeus (JCL) oil was extracted, refined and modified through epoxidation, hydroxylation and dehydration steps in order to increase the degree of unsaturation in the oil alkyl chain. The modified oil was subsequently used for alkyd resin preparation (50% oil formulation) using a two-stage alcoholysis-polyesterification method. Drying performances of white gloss paints formulated from the desaturated oil alkyd, considering a pigment-volume concentration of 20.67% gave improved results. Blending of the improved 50% JCL oil alkyd with acrylic further enhanced the drying properties and compare well with commercial standards. White gloss paint formulated from the improved JCL alkyd–acrylic blends (1:3) dried hard within 2 h at an outdoor temperature of 37 °C ± 2.Item Mineral Characterization of Yombo-Fitta - An African Natural Hair Dye(2011) Adebayo, G.B.; Adekola, F.A; Olatunji, G.A.Mineral contents of an African hair dye were investigated. Some physiochemical properties such as solubility, pH, ash and organic content were first carried out. Combinations of XRF, XRD, SEM, IR, and UV-VISIBLE spectroscopic techniques were employed in the investigation. The dye was found to dissolve in all the ten aqueous and nonaqueous media used. The pH of the aqueous solution was found to be 8.6. Ash and organic contents of the raw dye were found to be 51% and 49% respectively. The XRF revealed that the dye contains twenty elements which include K, Ca, Ti, V, Cr, Zn, Mn, Fe, Co, Ni, Cu, As, Nb, Zr, Rb, Sr, Y, Mo and Br, with concentrations ranging from major to ultra-trace levels. The XRD also showed that the sample contains about forty six mineral phases which include both inorganic and organic components. The optical microscopic investigation gave indication that the dye was likely to be of the marine origin. The infrared (IR) measurements indicated that the sample contained functional groups such as C=O, C=C, C-C, CN, aromatic ring and metal-carbon chelate rings. The UV-VIS spectra show that the dye absorbed in the visible region with λmax of the aqueous solution being 464.0 nm.Item Preparation and evaluation of Jatropha curcas Linneaus seed oil alkyd resins(Elsevier, 2010) Odetoye, T.E; Ogunniyi, D.S.; Olatunji, G.A.Jatropha curcas Linnaeus (JCL) seed oil was utilized in the preparation of four sets of alkyd resin (35%, 50%, 60% and 75% oil formulations) using a two-stage alcoholysis–polyesterification method. The rates of polyesterification depended on the amount of oil used during synthesis. The properties of the alkyds were evaluated. The range of solidification times was between 278 and 442 s; also the range of film thickness was between 0.014 and 0.08 mm, and the alkyds were readily soluble in turpentine, xylene and butanol. Inclusion of cobalt naphthenate as drier and outdoor temperature (37 °C ± 2) improved the drying properties of all the alkyds. The colours of white gloss paints formulated from the alkyds, considering a pigment-volume concentration of 20.67% in the gloss paint formulation, compared well with that of a paint formulated using a commercial alkyd sample. 1H NMR analysis confirms the expected structure of the alkyds.Item Production and characterization of biodiesel using palm kernel oil, fresh and recovered from spent bleaching earth(Green Wave Publishing of Canada, 2014) Aladetuyi, A.; Olatunji, G.A.; Ogunniyi, D.S.; Odetoye, T.E.; Oguntoye, S.O.Palm kernel oil (PKO) was recovered from spent bleaching earth with a yield of 16 %, using n-hexane while the fresh oil was extracted from palm kernel with n-hexane and a yield of 40.23% was obtained. These oils were trans-esterified with methanol under the same reaction conditions: 100 oC, 2 h reaction time, and oil-methanol ratio of 5:1 (w/v). The cocoa pod ash (CPA) was compared with potassium hydroxide (KOH) as catalyst. The percentage yields of biodiesel obtained from PKO catalysed by CPA and KOH were 94 and 90%, respectively. While the yields achieved using the recovered oil catalysed by CPA and KOH were measured at 86 and 81.20 %. The physico-chemical properties of the biodiesel produced showed that the flash point, viscosity, density, ash content, percentage carbon content, specific gravity and the acid value fell within American Society for Testing and Materials (ASTM) specifications for biodiesel. The findings of this study suggest that agricultural residues such as CPA used in this study could be explored as alternatives for KOH catalyst for biodiesel production.Item Studies on the preparation of Parinari polyandra Benth seed oil alkyd resins(Wiley, 2013) Odetoye, T.E; Ogunniyi, D.S.; Olatunji, G.A.Parinari polyandra Benth seed oil was utilized in the preparation of four sets of alkyd resin (35%, 50%, 60%, and 75% oil formulations) using a two‐stage alcoholysis‐polyesterification method. The rate of polyesterification was depended on the amount of oil used during synthesis. The properties of the alkyds (drying times, film characteristics, water and acid resistances, and solubility) were evaluated using relevant standards. Inclusion of cobalt naphthenate drier in the alkyds and their exposure to outdoor temperature improved the drying properties. White gloss paints formulated from the alkyds, considering a pigment‐volume concentration of 20.67% in the gloss paint formulation compare well with commercial standard. FTIR and 1H‐NMR analysis confirm the alkyd (glycerol‐phthalate) structure.Item Studies on the preparation of Parinari polyandra Benth seed oil alkyd resins(Wiley, 2013) Odetoye, T.E.; Ogunniyi, D.S.; Olatunji, G.A.Parinari polyandra Benth seed oil was utilized in the preparation of four sets of alkyd resin (35%, 50%, 60%, and 75% oil formulations) using a two‐stage alcoholysis‐polyesterification method. The rate of polyesterification was depended on the amount of oil used during synthesis. The properties of the alkyds (drying times, film characteristics, water and acid resistances, and solubility) were evaluated using relevant standards. Inclusion of cobalt naphthenate drier in the alkyds and their exposure to outdoor temperature improved the drying properties. White gloss paints formulated from the alkyds, considering a pigment‐volume concentration of 20.67% in the gloss paint formulation compare well with commercial standard. FTIR and 1H‐NMR analysis confirm the alkyd (glycerol‐phthalate) structure.