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Item Open Access ASSESSMENT OF GROUND-WATER AND STREAM QUALITY FOR TRACE METALS AND PHYSICO-CHEMICAL CONTAMINATIONS IN TOTO LOCAL GOVERNMENT AREA OF NASARAWA STATE, NIGERIA(FACULTY OF NATURAL AND APPLIED SCIENCE NASARAWA STATE UNIVERSITY, KEFFI., 2008-08-02) Aremu, M. O.; Sangari, D. U.; Musa, B. Z.; Chaanda, M. S.Water samples collected from nine sampling points of three different sources (Well, Bore-hole and Stream) within Toto Local Government Area of Nasarawa State, Nigeria were analysed for trace metals and physico-chemical properties. The trace metals Na, K, Cu, Mg, Fe, Ca, Zn, Pb, Cd, As, Se, Cr and Hg were analysed using atomic absorption spectrophotometric method. Alkalinity, pH, temperature, turbidity, conductivity, total solids, total dissolved solids, suspended solids and soluble anions such as phosphate, chloride, nitrate and bicarbonate were the physico-chemical parameters analysed using standard techniques. The results showed that Cd and Hg were not at detectable range for all the water samples. High spatial variations in the concentrations of the metals and physico-chemical parameters determined were recorded. The trace heavy metals were below the deleterious level while the physico-chemical properties of the water were within the required standard limits set by World Health Organisation (WHO) for drinking water except phosphate ion. However source protection is proposed for these waters for the benefit of mankindItem Open Access SYNTHESIS AND FLUORESCENCE CHARACTERISTICS OF 2-A-ANILINOPURINE, 2-/VPIPERIDINOPURINE, 6-A-ANILINOPURINE AND 6-A-PIPERIDINOPURINE(FACULTY OF NATURAL AND APPLIED SCIENCE NASARAWA STATE UNIVERSITY, KEFFI., 2008-08-01) Abdullah, Z.; Bakar, M. A. A; Idris, A. Mohd2-Fluoropurine was prepared from 2aminopurine through a diazotization reaction, followed by treatment with Jluoroboric acid. 2-Aminopurine was obtained from a series of reactions, using 5-nitrouracil as the starting material. 2- N-Piperidino and 2- N-anilinopurines were obtained by treating 2-fluoropurine with piperidine and aniline respectively. 6-N-Piperidino and 6-N-anilinopurines were obtained by treating 6-chloropurine with piperidine and aniline. Fluorescence studies were carried out in various solvents and maximum fluorescence was observed in 75% ethanol. 2- Aminopurine showed the highest fluorescence intensity, followed by 2-N-anilino and 2-N-piperidinopurines. 6- Substituted purines showed stronger fluorescence intensities compared to 2-substitutedpurinesItem Open Access Kinetics and Mechanism of Oxidation of L – Methionine by Potassium Bromate in Aqueous Hydrochloric Acid Medium(Department of Chemistry, Nasarawa State University Keffi, 2010-01-05) Idris, S.O.; Ibrahim, A.P.; Iyun, J.F.; Mohammed, Y.The kinetics of the oxidation of L - methionine by bromate ions in aqueous acidic medium at a constant ionic strength, µ , of 0.50 mol dm–3 were investigated spectrophotometrically at temperature of 30.0 ± 1ºC. The reaction shows a stoichiometry of 1:2 (Methionine/ bromate), first order kinetics in [methionine], first order in [bromate] and second order dependence in [H+]. An increase in ionic strength and a decrease in dielectric constant of the reaction medium increase the rate of reaction. The reaction is catalysed by anions. Polymerization test conducted suggests the absence of free radicals. The results obtained from this study supports the operation of outer – sphere mechanism. A plausible mechanism is proposed for the reaction.Item Open Access Mechanism of the Redox Reaction of Hydroxylamine and Bromate Ions in Aqueous Hydrochloric Acid Medium(Department of Chemistry, Nasarawa State University Keffi, 2010-03-03) Idris, S.O.; Sunday, E.; Iyun, J.F.; Mohammed, Y.Redox kinetics of the reaction of hydroxylamine hydrochloride (H2NOH.HCl) and BrO3– was carried out in aqueous acidic medium, at temperature of 29.5 ± 0.5ºC; ionic strength µ = 1.0 mol dm–3 (NaCl), [H+] = 1.0 x 10–2 mol dm–3 (HCl). The reaction showed a stoichiometry of 1:1.3, first order kinetics in both [NH3OH+] and [BrO3–], dependence on acid concentrations, positive salt effect, catalysis due to anions and absence of evidence of intermediate complex formation. Rate equation for the reaction has been proposed as: –d[NH3OH+]/ dt =(a[H+])[ NH3OH+][ BrO3–]. The second order rate constant for the NH3OH+– BrO3– reaction was found to be 0.233 dm3 mol–1 s–1. Based on the results obtained experimentally, the outer – sphere mechanism is suggested for the reactionItem Open Access INVESTIGATIONS INTO THE KINETICS AND MECHANISM OF THE ELECTRON TRANSFER REACTIONS OF N- METHYL THIOUREA AND DIAQUOTETRAKIS(2,2’- BIPYRIDINE) - μ - OXODIRUTHENIUM (III) ION, IN AQUEOUS ACIDIC MEDIUM(Department of Chemistry, Nasarawa State University Keffi, 2014-03-05) Mohammed, Y.; Idris, S.O.; Iyun, J.F.The kinetics of the oxidation of n- Methyl thiourea (MTU) by diaquotetrakis (2,2’- bipyridine) - μ - oxodiruthenium (III) ion, [(bipy)4(H2O)2Ru2O]4+, in an HClO4 medium has been studied spectrophotometrically at a temperature, T = 30 ± 1°C, ionic strength, I = 0.5 mol dm-3 (NaClO4) and hydrogen ion concentration, [H+] = 5.0 x 10–2 mol dm-3. The stoichiometry of the reaction conformed to an overall equation [H2O(bipy)2RuORu(bipy)2H2O]4+ H+3CHN C NH2 + H2O 2[(H2O)2(bipy)2Ru]2+ + H3CHN C S S C NH2 NH S + 2 NH The reaction showed first order kinetics with respect to the dimer and [MTU], respectively, k2 = (3.14 ± 0.05) x 10–2 dm3 mol–1 s–1, and was inversely affected by changes in [H+]. Changes in ionic strength and dielectric constant of reaction medium and addition of ions to the reaction medium had no or little effect on the rate constants of the reaction. The reaction has been found to conform to the rate equation: –d[[(H2O)2Ru2O4+]/ dt = (a+b 1 [𝐻+] )[[(H2O)2Ru2O4+][MTU] The reaction is considered to proceed through the formation of ion – pairs which go on to decompose at the rate determining steps to give rise to free radicals which diamerise to form the reaction products. The reduction product was found to be disulfides and the reaction is considered to proceed through the outer sphere pathway. A plausible mechanism is proposed.Item Open Access VALUABLE POTENTIALS OF COWPEA HUSK WASTE(Department of Chemistry, Nasarawa State University Keffi, 2011-11-20) Oluwagbemiga, ALAYANDE.; Akinola, AKINLAB.; Deborah, OLALEKAN.; Babatunde, OKESOLA.Cowpea husks which are an abundant agro waste in Sub Sahara Africa were collected, dried and grinded. The elemental composition and surface morphology were investigated with Energy Dispersive X-ray Microanalysis and Scanning Electron Microscope (SEM) respectively. The husks contain C, O, Al, Si, K and Ca. The husks have the potential to be processed to other valuable materials which can be applied in construction, electronic and other industries.Item Open Access QUALITY OF GROUNDWATER SOURCES IN KEFFI AND KARU LOCAL GOVERNMENT AREAS, NIGERIA(Department of Chemistry, Nasarawa State University Keffi, 2020-01-05) Opaluwa, O.D.; Mohammed, Y.; Shammah, Emmanuel ChakuThe quality of water from boreholes and hand dug wells in Keffi and Karu Local Government Areas, Nasarawa State, Nigeria were studied to ascertain the suitability of water from these sources for domestic purpose. The study was done by analysing for some physicochemical parameters using standard methods. The parameters determined were temperature, turbidity, total dissolved solids, total suspended solids, pH, electrical conductivity (EC), alkalinity, dissolved oxygen (DO), chemical oxygen demand (COD), nitrate, chloride, phosphate and sulphate. Water Quality Index for the different samples each was calculated to ascertain suitability of the water for usage. Results obtained for physicochemical parameters showed that COD had values higher than the recommended tolerable limit prescribed by Standards Organization of Nigeria (SON) while all the other parameters determined had values lower or within the recommended limits. WQI calculated showed that water from boreholes in Keffi was good for usage but water from hand dug wells in Keffi and boreholes and hand dug wells in Karu was not suitable for usage as potable water. Statistical analyses done at 95% confidence limit (p<0.05) showed there was no significant differences between physicochemical parameters of water samples from boreholes and wells from Keffi and Karu except for turbidity. However, the water from the study areas have very poor water quality, and it is better for water from these sources to be treated before being used for human consumption.Item Open Access Assessment of Water Quality Index and Heavy Metal Contents of Underground Water Sources in Doma Local Government Area, Nasarawa State, Nigeria(Department of Chemistry, Nasarawa State University Keffi, 2020-08-05) Opulawo, O.D.; Mohammed, Y.; Mamman, Suwaibat; Ogah, Adamu Tanko; Ali, DanjumaWater quality index and heavy metal contents of underground water sources in Doma Local Government Area, Nasarawa State, Nigeria was assessed to ascertain the suitability of the water for domestic purpose. Physicochemical parameters; temperature, turbidity, TDS, TSS, pH, EC, total hardness, alkalinity, chloride, nitrate and sulphates in the water samples were determined using standard methods of analysis. The water quality index (WQI) was also evaluated using known standard method. The heavy metal contents were determined using atomic absorption spectrophotometric method. The results of the physicochemical analyses shows that in borehole and hand dug well water, the respective mean values were temperature (27.11±0.45 and 27.41±0.55 °C), turbidity (1.51±0.54 and 2.56±1.04 NTU), TDS (230.00±87.75 and 358.67±91.46 mg/dm3), TSS (3.64±1.25 and 4.17±4.17 mg/dm3), pH (5.63±0.69 and 6.60±0.95), EC 277.16 and 296.29±26.52 µS/cm), total hardness (90.00±15.55 and 125.13±16.33 mg/dm3), alkalinity (8.87±.083 and 9.24±1.08 mg/dm3), chloride (20.59±14.62 and 21.22±10.13 mg/dm3, nitrate (0.024±0.04 and 0.01±0.01 mg/dm3) and sulphates (1.05±0.74 and 2.09±0.45 mg/dm3). It was revealed that all the physicochemical parameters for both borehole and hand dug well water had values that were within the standard permissible values recommended by regulatory bodies, NSDWQ and WHO except for the pH of the borehole water which was not within the recommended range and which showed the water to be slightly acidic and which could attributable to the nature of the host rocks. WQI for borehole and hand dug well water were 29.65 and 27.38 respectively with the implication that both water sources presented good water quality for drinking based on the water quality index and water quality status. The results of the heavy metal analyses shows that in borehole and hand dug well water, the respective mean values were Cd (0.003±0.002 and 0.010±0.002 mg/dm3), Cr (0.187±0.075 and 0.19±0.070 mg/dm3), Cu (0.040±0.010 and 0.804±0.805 mg/dm3), Fe (0.500±0.330 and 0.916±0.543 mg/dm3), Pb (0.010±0.010 and 0.015±0.007 mg/dm3) and Zn (0.290±0.120 and 0.072±0.072 mg/dm3). The results shows that Cd, Cu, Pb and Zn for both borehole and hand dug well water had mean values that were within the standard permissible values recommended by NSDWQ and WHO while Cr and Fe had mean values that were higher and which can be attributed to anthropogenic activities close to the water sources. It is recommended the groundwater in these selected communities be monitored regularly and that there is the need for the water to be treated before use because of those parameters that are off the standards to avoid associated health risks.Item Open Access Redox Kinetics and Mechanism of the Oxidation of Thiourea by Diaquotetrakis(2,2’- Bipyridine) - µ - Oxodiruthenium (III) Ion, in Aqueous Perchloric Acid(Department of Chemistry Education, Nasarawa State University Keffi, 2014-08-08) Mohammed, Y.; Idris, S.O.; Iyun, J.F.The kinetics of the oxidation of thiocarbamide (thiourea) by diaquotetrakis(2,2’- bipyridine) - µ - oxodiruthenium (III) ion, [(bpy)2(H2O)RuORu(H2O)(bpy)2]4+, in perchloric acid has been investigated at a temperature, T = 30±1ºC, ionic strength, I = 0.5 mol dm-3 (NaClO4) and hydrogen ion concentration, [H+] = 5.0 x 10–2 mol dm-3. The reaction showed a stoichiometry of 1:2 (oxidant/ thiourea), first order kinetics with respect to the thiourea (RSH), k2 = (7.39±0.05) dm3 mol–1 s–1, inverse [H+] dependence and zero salt effect. The rate equation for the reaction has been proposed – d[(bpy)2(H2O)RuORu(H2O)(bpy)2]4+]/dt=(a+b[ ])[(bpy)2(H2O)RuORu(H2O)(bpy)2]4+[RSH]. Outer sphere mechanism is implicated to operate in this reaction as evidenced by lack of the formation of a stable intermediate complex as suggested by absence of intercept in the Michaelis - Menten plot, lack of shift in λmax of the reaction mixture 1 minute after start of reaction and absence of observable anion catalysis. A plausible mechanism is proposed.Item Open Access Kinetic approach to the mechanism of the redox reaction of malachite green and permanganate ion in aqueous acidic medium(Department of Chemistry, Nasarawa State University Keffi, 2009-11-09) Mohammed, Y.; Iyun, J.F.; Idris, S.O.The redox kinetic and mechanistic studies of the reactions of malachite green (MG+) and MnO4– were carried out in aqueous acidic medium, at a temperature of 32.5 ± 0.5°C; ionic strength, µµµµ = 0.50 mol dm–3 (Na2SO4), [H+] = 5.00 x 10–3 mol dm–3 (H2SO4). In the stoichiometry, one mole of malachite green was consumed by one mole of MnO4–. The reaction is first order in both [MG+] and the [MnO4–]. The rates of redox reaction showed dependence on acid concentrations (in the acid range used). Rate equation for the reaction has been proposed as: –d[MG+]/ dt = (a + b[H+])[MG+][MnO4–]. At [H+] = 5.00 x 10–3 mol dm– 3, the second order rate constant for the malachite green – MnO4– reaction was found to be (11.96 ± 0.13) x 10–3 dm3 mol–1 s–1. The rates of reaction displayed negative salt effect. Log k1 versus 1/D gave positive slope for the reaction. Added anions and cations catalysed the malachite green – MnO4– reaction. Results of the Michaelis- Menten analysis gave no evidence of intermediate complex formation. Based on the results obtained experimentally, the outer sphere mechanism is proposed for the malachite green – MnO4– reaction.Item Open Access Kinetics and mechanism of the reduction of diaquotetrakis (2,20-bipyridine)-l-oxodiruthenium(III) ion by hypophosphorous acid in acidic medium(Department of Chemistry, Nasarawa State University Keffi, 2017-03-13) Mohammed, Y.; Idris, S.O.; Onu, A.D.The kinetics and mechanism of the reduction of diaquotetrakis(2,20-bipyridine)-l-oxodiruthenium(III), [(H2O)2(bipy)4Ru2O]4?, by H3PO2 has been studied in aqueous acid at ionic strength = 0.5 mol dm-3 (NaClO4), [H?] = 5.0 9 10-2 mol dm-3 and temperature = 31 ± 1 �C. Measurement of the stoichiometry showed that 1 mole of [(H2O)2(bipy)4Ru2O]4? was reduced by 1 mole of H3PO2. The reaction was found to be first order with respect to both [(H2O)2(bipy)4Ru2O4?] and [H3PO2], hence second order overall. Variations in the ionic strength and dielectric constant of the reaction medium had no effect on the rate. Also, addition of various ions to the reaction medium did not significantly alter the rate. Free radicals were identified during the course of the reaction by a polymerisation test. Spectroscopic information and Michaelis–Menten plots suggested the absence of an intermediate complex prior to electron transfer. [(H2O)2 (bipy)2Ru]2?, the reduction product of [(H2O)2(bipy)4 Ru2O]4?, plus H3PO3, the oxidation product of H3PO2, were identified in the product solutions. It is suggested that the reaction proceeds through the outer sphere pathway. A mechanism for the reaction is proposed.Item Open Access HEXAMETHYLPARAROSALININE CHLORIDE (CRYSTAL VIOLET) OXIDATION BY CHLORATE IONS IN AQUEOUS ACIDIC MEDIUM : KINETIC APPROACH TO THE MECHANISM OF REACTION(Department of Chemistry, Nasarawa State University Keffi, 2020-01-05) Mohammed, Y.; Etonihu, A.C.; Tsaku, V.A.The redox kinetic studies of the reaction of crystal violet (CV+) and ClO3– were carried out in aqueous acidic medium, at a temperature of 32 ± 1�C; � = 0.50 mol dm–3 (NaCl), [H+] = 1.00 x 10–2 mol dm–3 (HCl). In the stoichiometry, one mole of the dye was consumed by two moles of ClO3–. The reaction is first order in both [dye] and the [oxidant]. The rates of redox reaction showed dependence on acid concentrations (in the acid range used). Rate equation for the reaction has been proposed as: –d[MG+]/ dt = ( b[H+])[CV+][ClO3–]. At [H+] = 1.00 x 10–2 mol dm–3, the second order rate constant for the crystal violet – ClO3– reaction was found to be 3.88 dm3 mol–1 min–1. The rate of reaction displayed zero salt effect and was not affected by changes in the dielectric constant of the reaction medium. Added anions and cations catalysed the crystal violet/ ClO3– reaction. Results of the Michaelis- Menten analysis gave no evidence of intermediate complex formation. Based on the results obtained experimentally, the outer sphere mechanism is proposed for the crystal violet – ClO3–reaction and a plausible mechanism of the reaction is proposed.Item Open Access Investigations into the kinetics and mechanism of Cr (VI) oxidation of hexamethylpararosalinine chloride in aqeuous acidic medium(Department of Chemistry, Nasarawa State University Keffi, 2010-04-28) Mohammed, Y.; Komolafe, O.A.Investigations into the kinetics and mechanism of the redox reaction of hexamethylpararosalinine (HPR+) and Cr (VI) were carried out in aqueous acidic medium, at a temperature of 31.0 ± 1°C; m = 0.50 mol dm–3 (NaCl), [H+] = 5.00 x 10–3 mol dm–3 (HCl). The reaction displayed a stoichiometry of 1:1, first order dependence in both [dye] and [oxidant], dependence on acid concentrations (in the acid range used), negative salt effect, catalysed by added cations and anions and no evidence of intermediate complex formation. Rate equation for the reaction has been proposed as: –d[MG+]/ dt = (a + b[H+])[HPR+][Cr2O72–] and the second order rate constant for the reaction was found to be (11.96 ± 0.13) x 10–3 dm3 mol–1 s–1. Log k1 versus 1/D gave positive slope for the reaction. Based on the results obtained experimentally, the outer sphere mechanism is proposed for the reaction.Item Open Access Amino Acid Profile and Vitamin C Content of Selected Condiments Used as Thickeners in Soup Preparation(Department of Chemistry, Nasarawa State University Keffi, 2021-07-30) Lawal, Halimatu Sadiya; Madu, Paschal Chima; Opaluwa, O.D.; Mohammed, Y.This study aimed to analyze the amino acid profile and determine the vitamin C content of the condiments named Detarium microcarpum (DM), Cissus populnea (CP), Grewia mollis (GW) and Parkia biglobosa (PB). Study Design: The condiments obtained from Gwagwa market, Federal Capital Territory (FCT), Abuja were used for this study to analyze and determine the amino acid profile and vitamin C content. Place and Duration of the Study: The study was conducted in Abuja, Nigeria at the Department of Medicinal Chemistry and Quality Control, National Institute for Pharmaceutical Research and Development [NIPRD], from February 2020 to September 2020. Methodology: The amino acid profile of the condiments was analyzed using methods described by (Maria et al., 2004). The samples were dried to constant weight, defatted, hydrolyzed, evaporated in a rotary evaporator and loaded into the Applied Biosystems PTH Amino Acid Analyzer while the Ascorbic acid content of the condiments was determined by titration method. Result: The result indicated that non- essential amino acids are higher in concentration in all the samples (PB - 33.77, DM - 27.51, GM - 18.21 and CO - 25.86) compared to the essential amino acids (PB -27.16, DM - 19.46, GM - 1 6.47 and CO - 22.38) and semi-essential amino acid (PB - 22.22, DM - 16.59, GM - 9.64, CO - 14.01). Among the essential amino acids, leucine is the predominant acid, while glutamic, aspartic acids were found to be the major non-essential amino acids in the samples. High concentrations of aspartic acid, glutamic acid valine, alanine and leucine predominate in all the samples analyzed. The sample Parkia biglobosa has the highest concentration of vitamin C with 0.3 mg/L followed by Detarium Microcarpum 0.18 mg/L, Grewia Mollis 0.12 mg/L and Cissus populnea 0.11 mg/L. Conclusion: Results indicate that these condiments contained amino acids in appropriate quantities that can serve as supplementary potential sources of essential amino acids to man and appreciable amount of vitamin CItem Open Access Oxidation Of N, N-Dimethylthiourea By Diaquotetrakis(2,2’- BIPYRIDINE) - µ - Oxodiruthenium (III) Ion In Aqueous Acid Medium: A Kinetic Approach To Mechanism Of Reaction(Department of Chemistry Education, Nasarawa State University Keffi, 2020-07-29) Mohammed, Y.; Idris, S.O.; Onu, A.D.; Opaluwa, O.D.Background: Electron transfer (redox) reactions play very important roles in many biological processes including collagen synthesis, steroid metabolism, the immune response, drug activation, neurotransmitter metabolism, nitrogen fixation, respiration and photosynthesis. Ruthenium complexes with polypyridyl ligands have received much attention owing to their interesting spectroscopic, photophysical, photochemical and electrochemical properties, which are responsible for their potential uses in diverse areas such as photosensitizers for photochemical conversion of solar energy. Thiourea and its derivatives, of which DMTU is one, can be oxidised by a wide variety of oxidising agents and the reaction pathways and final products of the oxidation reaction depend on the reagents used and condition of the reaction mixtures. Materials and Methods: Kinetic and mechanistic studies of the oxidation of N,N-dimethyl thiourea (DMTU) by diaquotetrakis(2,2’-bipyridine) - μ - oxodiruthenium (III) ion, hitherto referred to as Ru2O4+, has been carried out in hydrogen ion concentration, [H+] = 5.0 x 10–2 mol dm-3 (HClO4), ionic strength, I = 0.5 mol dm-3 (NaClO4) and at a temperature, T = 30±1ºC. Results: The reaction revealed that a stoichiometry of 2:1 (DMTU/ Ru2O4+, first order dependence with respect to [DMTU], an acid – independent and inverse acid dependent pathways. The reaction rates were not affected by changes in ionic strength and dielectric constant of the reaction medium. Addition of ions to the reaction medium had little or no effect on the reaction rates. There was evidence of the participation of free radicals in the reaction. There was no shift in λmax of the reaction mixture 1 minute after start of reaction. Michaelis Menten plot revealed no appreciable intercept. Conclusion: Based on the findings, an outersphere mechanism is implicated to operate in the reaction and a plausible mechanism is proposedItem Open Access STUDIES OF THE KINETICS AND MECHANISM OF THE ELEC TRON TRANSFER REACTIONS OF DIAQUOTETRAKIS(2,2’-BIPYRIDINE)-µ- OXODIRUTH ENIUM(III) ION AND DITHIONITE IN AQ UEOUS MEDIUM(Department of Chemistry, Nasarawa State University Keffi, 2016-02-05) Mohammed, Y.; Idris, S.O.; Onu, A.D.; Iyun, J.F.he kinetics and mechanism of the electron transfer reaction of diaquotetrakis(2,2’ -bipyridine)-µ- oxodiruthenium(III) ion (hereafter denoted as Ru2O4+ or [(H2O)2Ru2O]4+) and dithionite ions (S2O 42 ) has been studied in aqueous medium at ionic strength, I, = 0.5 mol dm-3 and temperature, T = 31±1 ºC. The stoichiometry of the reaction was found to be 1:1. The rate of reaction showed first order kinetics with respect to [Ru2O4+] and [S2O 24 ] respectively, second order overall. Rate equation for the reaction has been proposed as; d[((H2O)2Ru2O4+]/dt = kobs[((H2O)2Ru24+] = k2 [((H2O)2Ru2O4+][S2O42-] . Varying I and dielectric constant, D, of the reaction medium had no effect on the reaction rates, while free radicals were not detected in the course of the reaction. Product analysis revealed [(H2O)2(bpy)2Ru]2+as the reduction product of [(bpy)2(H2O)RuORu(H2O)(bpy)2]4+. Spectroscopic evidence of formation of stable intermediate complex was lacking which, in addition to absence of intercept in the Michaelis – Mentenplot and catalysis/ inhibition of the reaction due to added ions, suggest the implication of outer sphere mechanism operating in the reaction. A plausible mechanism was proposed.Item Open Access Effect of Different Sources of Heat on Nutritional Composition of Tilapia Fish (Oreochromis niloticus)(Department of Chemistry, Nasarawa State University Keffi, 2014-01-05) Aremu, M.O.; Namo, B.S.; Mohammed, Y.; Archibong, C.S.; Ogah, E.A study was conducted to investigate the effect of traditional smoking methods on fresh tilapia fish (Oreochromis niloticus). For this purpose, proximate, mineral and amino acid compositions of tilapia fish smoked with sawdust, rice bran, melon husk and electric oven (control) heat treatments were determined using standard analytical technique. The results showed that crude protein content (%) ranged between 55.10 to 64.16% with the highest value recorded in sample smoked with rice bran heat treatment while crude fat had the highest value (18.10%) also in rice bran smoked sample. Sodium was found to be more abundant in all the samples (5.75 – 10.10 mg/100g) compared with magnesium (5.45 – 9.15 mg/100g), potassium (4.55 – 6.45 mg/100g) and phosphorus (4.70 – 6.00 mg/100g) while the least abundant mineral was chromium (0.05 – 0.15 mg/100g). The harmful metals such as cadmium and lead were not at detectable range of atomic absorption spectrophotometer (AAS). The amino acid profile revealed that only Oreochromis niloticus fish sample smoked with sawdust enhanced the contents of total amino acid (TAA), total essential amino acid (TEAA) and total sulphur amino acid (TSAA) by 3.77, 3.95 and 7.03%, respectively while melon husk and rice bran heat treatments reduced TAA, TEAA and TSAA. The limiting amino acid (LAA) for all the samples with different heat treatments was Ile except sample smoked with rice bran which has Val as LAA. Generally, all the smoked samples contained nutritionally useful quantities of total essential amino acids.Item Open Access KINETICS AND ISOTHERM STUDIES FOR ADSORPTION OF METHYL RED ONTO COMMERCIAL ACTIVATED CARBON(Department of Chemistry, Nasarawa State University Keffi, 2011-11-10) L. G, Hassan.; B. N, Ajana; K. J, Umar.; D. M, Sahabi.; A. U., Itodos.; A., Uba.Batch equilibrium and kinetics studies were carried out to study the rate and mechanism of dye uptake by commercial activated carbon. The percentage attrition (hardness),Bulk Density, Ash Content and methylene blue (mesoporosity) test were investigated. Comparison of the best fit model was made by evaluating the goodness of fit using the correlation coefficient values. (R2), sum of squares error (SSE) and the standard error (SE) of the estimate, which follow the trend, langmuir (R2=0.959, SSE=3.889, SE=3.118)>Freundlich (R2=0.901, SSE-9.449, SE=4.860). The smaller the values of SSE and SE, he better the curve fitting. Langmuir model gave the best curve fitting with smaller values of SSE and SE. The maximum theoretical adsorption capacity (q„J of the activated carbon was also evaluated using the Langmuir model the and the q^ was found to be 64.10 which shows that the activated carbon has a good adsorption capacity. The Elcmic and Intraparticle diffusion kinetic models were both applied to the adsorption kinetic data obtained. The Elovic equation gave the best fit with correlation coefficient of (0.995) and Intraparticle diffusion model (0.951).Item Open Access Phytochemical Screening and Antioxidant Activity of Balanites Aegyptiaca Root Bark Extracts: Influence of solvent(Department of Chemistry, Nasarawa State University Keffi, 2020-05-05) Usman, A.; Mohammed, Y.; Muhammed, N.L.; Usman, N/A; Zakari, A.H.Balanites aegyptiaca (L) Del is a medic- inal plant used in Africa’s folk medicines to treat wide range of diseases. Phytochemical screening of aqueous and ethanolic extracts of Balanites ae- gyptiaca (L) Del root indicated the presence of flavonoids, saponins, tannins and phenols.The ethanolic extract of the plant root had in addition carbohydrate, cardiac glycoside and steroids while n-hexane extract indicated the presence of anthraquinone, carbohydrates, cardiac glycoside, terpenoids and resins. The extracts were also eval- uated for their free radical scavenging potential, total phenolic and total flavonoid contents. The antioxidant activity was determined using 1,1-di- phenyl-2-picrylhydrazyl (DPPH) assay, the total phenolic content was evaluated using Folin-Cio- calteau assay, while the total flavonoid content was assessed by the aluminium chloride colori- metric assay. The results obtained revealed that the ethanolic extract exhibited higher total antiox- idant capacity in the range of 55.23±0.4 to 81.04±0.9% while concentrations in the aqueous extract ranged from 20.15±0.2 to 35.11±0.2% compared to 80 % of standard ascorbic acids. Es- timated total phenolic content in aqueous and eth- anolic extracts were 179.48±1.99 and 260.07±2.31 mg/gallic acid equivalent (GAE)/g respectively. However, the total flavonoid content for aquoues and ethanolic extracts were 69.17±0.32 and 95.52±0.41 mg/ quercetin equiva- lent (QE)/g respectively. Total phenol and flavo- noid were absent in normal hexane extract. The results obtained from the study indicated that the choice of solvent can influence the components that can be extracted from Balanites aegyptiaca (L) Del root and that for optimum extracts to be obtained, the best solvent is ethanol.Item Open Access Phytochemicals, Antibacterial, Antioxidant and Cytotoxic Analyses of Balanites Aegyptiaca Stem Bark Extracts(Department of Chemistry, Nasarawa State University Keffi, 2020-03-03) Usman, A.; Mohammed, Y.; Opulawo, O.D.Powdered stem bark of B. aegyptiaca was extracted using ethanol, aqueous and n-hexane. Test for the secondary metabolites showed the presence of flavonoids, saponins, tannins, phenols and carbohydrates in aqueous and ethanol extracts, while ethanol extract has in addition cardiac glycoside and steroids. Anthraquinone was the only metabolite detected in n-hexane extract. The antibacterial activity of the plant extracts showed ethanol extract to have a broad spectrum of activity against the test isolates with varying zones of inhibition, as shown by the results of the minimum inhibitory concentration (MIC) which for hexane extract was obtained at 50 mg/ml for S. aureus, while that of ethanol extract was obtained at25mg/ml for S. typhi, 50 mg/ml for E.coli and 100 mg/ml for S. aureus. However, the test organisms were not susceptible to the aqueous extract. DPPH (1,1- diphenyl-2 picrylhydrazyl) free radical scavenging assay was used to determine the antioxidant property of the extracts. The result showed that DPPH% inhibition varied between extracts with ethanol extract having a maximum of 80% while aqueous extract had 32% inhibition. The crude extracts of the plant sample were also subjected to brine shrimp lethality bioassay. The results obtained were 0.46, 3.13, 9.70 and13.35μg/ml for vincristine sulphate, hexane, ethanol and aqueous extracts respectively. Comparing this result with the standard vincristine sulphate, hexane extract showed significant cytotoxicity having LC50 of 3.13μg/ml.