ChemSearch Journal

Effect of reaction conditions on the Claisen-Schmidt synthesis of selected 1,3-diphenylprop-2-en-1-one derivatives

2024-07-10T05:49:18+00:00

This research aimed to investigate the Claisen-Schmidt condensation reaction for the wet synthesis of chalcones and suggest the ideal reaction conditions for the process. Three chalcones, namely 1,3-diphenylprop-2-en-1-one, 1-(4-nitrophenyl)-3-phenylprop-2-en-1-one and 3-(2,4,6-trimethoxyphenyl)-1-phenylprop-2-en-1-one, were synthesized under varying conditions while closely monitoring the effects on product yield and quality. The temperature was varied between room and ice bath (<10ºC) conditions. Cold aqueous NaOH and KOH were varied as catalysts while absolute ethanol or methanol was used as the solvent in each scenario. Thin layer chromatography (TLC) was employed to monitor the progress of the reaction. The open capillary method was used to determine the melting point of the products and the values obtained were uncorrected. The results obtained showed that a combination of methanol as a solvent and NaOH as a catalyst, under ice-cold condition, was optimum for the wet synthesis of the chalcones. This combination gave the highest yield (98.26%) and purity of products.

Efficient removal of Congo red dye from aqueous solution using a biosorbent derived from Phoenix dactylifera seeds: exploring kinetic and thermodynamic parameters

2024-07-10T05:54:42+00:00

In this research work, Phoenix dactylifera seeds (PDS) was used as an adsorbent for the removal of Congo red dye from aqueous system. Congo red (CR), a typical anionic diazo dye is very difficult to remove from aqueous solutions because of it thermal physicochemical and optical stability which is due to it aromatic structure. Therefore, the removal of CR from aqueous solutions using low cost and sustainable biosorbent is highly necessary. The adsorbent was characterized using Fourier transform infrared spectroscopy (FTIR). The effect of various adsorption parameters such as initial dye concentration, adsorbent dosage, contact time, pH and temperature were optimized for maximum sorption of dye. It was found that percentage removal of the CR dye decreases as pH increases from acidic to basic region. Freundlich and Langmuir isotherms were applied for the interpretation of experimental data. The Langmuir isotherm model was found to give best fit for the adsorption with maximum adsorption capacity of 51.245 mg g⁻¹. The thermodynamic parameters such as Gibb’s free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were found to be −4.38 kJ/mol, 54.9 kJ/mol and 0.1836 kJ/mol/K respectively. The kinetic studies showed that the adsorption was best described by pseudo-second order kinetic model. The results of thermodynamic studies inferred that adsorption of CR onto Phoenix dactylifera seeds was highly feasible, spontaneous and endothermic.

Hydrochemical and geothermometric study of thermal waters of Kaswa/Mahagi in Ituri Province, Democratic Republic of the Congo

2024-07-10T06:03:28+00:00

The thermal waters of Kaswa/Mahagi, located in the Albertine Rift (North-East of the Democratic Republic of the Congo) constitute a hydrogeochemical and geothermal potential that the country needs for its development. This study aimed to determine the lithological nature and the temperature of the reservoir of these waters. The combination of Hydrogeochemical and statistical methods made it possible to achieve these objectives. The thermal waters of Kaswa/Mahagi, volcanic waters of origin are essentially evaporitic in its lithological nature, the bedrock calcium chloride sulfate. The identified metallic trace elements and their distribution in the thermal waters of Kaswa/Mahagi were: Fe²⁺(4.36mg/L) > Pb²⁺(3.84mg/L) > Zn²⁺(1.03mg/L) > Cu²⁺(0.48mg/L) > Mn²⁺(0.18mg/L) > Cr³⁺(0.09mg/L). The concentrations of Cd²⁺, Ni²⁺, Hg²⁺, Bi³⁺ and Sn2+ were less than 0.02 mg/L. Certain metallic trace elements were in significant concentrations, thus reflecting their circulation in depths. The application of SiO2 geothermometers showed that their temperature in the deep reservoir oscillates between 70 and 75°C, while the geothermometers of Na-K-Ca displayed an average temperature of 89°C; the thermal loss being important considering the temperature measured at emergence and attributed to many factors. These results are useful for integrated management of water resources and the exploitation of geothermal potential for the benefit of the population.

Effects of cassava processing effluents on the soil microbial population dynamics in selected communities in Abakaliki, Ebonyi State, Nigeria

2024-07-10T10:13:39+00:00

Cassava processing effluent constitutes environmental nuisance and pollutes both soil and water which releases foul odour causing air-pollution. This study evaluated the effects of cassava mill effluent on the microbial population dynamics and physicochemical characteristics of soil in selected communities in Abakaliki, Ebonyi State. Soil samples were collected in a depth of 0-20 cm from both cassava mill effluent polluted soil and unpolluted soil samples for three month and conveyed to the laboratory for analysis. The result showed that there was significant difference (p<0.05) in the microbial (bacterial and fungal) population between the polluted and unpolluted sites. Bacterial population ranged from 4.0±0.2x10⁶ Cfu/g to 8.6±0.8x10⁶ Cfu/g, while fungal population ranged from 1.4±0.1 to 3.4 ± 0.3x10⁶ Cfu/g across the three months study period. Most of the bacteria species identified in the polluted and unpolluted sites includes; E. coli, Bacillus species Staphylococcus aureus, Klebsiella pneumonia, Shigella species, Pseudomonas aeroginosa and Proteus species, while fungal species isolated from the polluted site was the Articulospora inflata while the mold, Aspergillus species and the Penicillium species were commonly found in both polluted and unpolluted sites. The physicochemical properties of the soil samples showed that there was no significant difference in the physicochemical characteristics of both polluted and unpolluted sites although the soil physicochemical properties differed very significantly (P<0.001) across the locations studied. Most of the physicochemical parameters were higher in the polluted soils compared to their unpolluted counterparts except for the exchangeable cations. This study showed that there is a shift in microbial population structure in soils polluted with cassava mill effluent. However, although this increases most physicochemical properties of the contaminated soil such as pH, OC, OM, N and P, it did not lead to significant shift in these parameters in the three months study period across the locations. This study has elucidated the nature of changes in both microbial population structure and physicochemical properties of soil exposed to cassava effluent pollution.

Spectroscopic profiles and solubilisation kinetics of methylene blue dye in unwholesome liquid detergents

2024-07-10T10:21:59+00:00

The spectroscopic profiles and solubilisation kinetics of Methylene blue in unwholesome liquid detergents was carried out using mechanical shaker and BK-UV 1900 PC Scanning Spectrophotometer. Sodium dodecyl benzene sulphonate (SDBS) served as control (1), while the registered Potential fabric wash (PFW) served as control (2). Test fabric wash (TFW), test car wash (TCW), test dish water (TDW) and test toilet wash (TTW) were used as unwholesome liquid detergents. Pieces of white cotton fabrics were stained with known concentration of MB and solubilised with known concentrations of the liquid detergents. The effects of dye dosage, detergent dosage, contact time, detergency, solubilisation kinetics and percent weight lost were studied. Data from the research showed that the extent of solubilisation of dyes increased with increasing initial MB and detergents concentrations. The solubilisation kinetics was determined using pseudo first and second order kinetic models. The percent removal of dye from white cotton fabrics using individual detergents at equilibrium times gave the following result in that order: SDBS(99.60) > PFW(67.13) > TFW(62.30) > TDW(45.52) > TTW(37.93 ) >TCW(21.38). Kinetic studies of the detergents revealed that 2^nd order kinetics was relatively more effective for describing the whole detergents solubilisation process. Percent fabric lost showed that all unwholesome liquid detergents have high percent loss ranging between 1.36-2.97 as compared with the registered PFW(0.49) detergent. The present work aims to examine the solubilisation of methylene blue dye in registered and unwholesome liquid detergents concerning detergents concentrations, dye/detergent dosage, contact time, detergency, weight loss and solubilisation kinetics of dye in known concentrations and their (registered and unwholesome liquid detergents) solubilisation efficiencies compared. The results showed that NAFDAC registered (PFW) liquid detergent showed better percent active ingredient, concentration, detergency and washing efficiency than all the unwholesome liquid detergents.

Photosensitizing activity and photostability of Hibiscus sabdariffa calyces

2024-07-10T10:29:39+00:00

The vivid red colour of Hibiscus sabdariffa calyces (Roselle) extract is due to the presence of anthocyanins, which have found uses in food and beverage colouring and other dyeing-related applications. In the present study, stability of the anthocyanins of the methanol extract of Hibiscus sabdariffa calyces was examined by exposing it to light and measuring the decrease in absorption with time. Also, its ability to photosensitize the reaction of a conjugated diene with singlet oxygen was compared to that of methylene blue, which is commonly used. The degradation pattern monitored by absorbance measurement was tested at a significance level of 0.05 and was found to be statistically significant. Its photosensitization was also confirmed by its ability to induce the formation of endoperoxides in the photooxygenation of conjugated cyclohexadiene in ambient light. This was monitored using thin layer chromatography. Thus, Hibiscus sabdariffa calyces extract may be used as a photosensitizer in fine chemical synthesis, and as a natural colorant, however with care in storage and handling.

Energetics and temperature dependent behaviour of amitriptyline hydrochloride with conventional surfactant in aqueous medium

2024-07-10T10:36:11+00:00

The use of surfactants for improved solubilization of hydrophobic drugs is of great pharmacological significant. This study investigates the interaction of a nitrogen-based surfactant, cetyltrimethylammonium bromide (CTABr) with varied concentrations of a tricyclic antidepressant drug, amitriptyline hydrochloride (AHCl), at different temperatures, 298.1 – 318.1 K with a view to determine the energetics of the system. The critical micelle concentration for the system (C^SYS) occurred far below that for CTABr at 6.65x10⁻⁴ − 9.01x10⁻⁴moldm⁻³, indicating a favourable interaction. In addition, the change in Gibbs free energy ΔG_SYS (kJmol⁻¹) of the system was both temperature and concentration dependent and varied from - 7.71 to -51.479. The results of enthalpy (ΔH_SYS) and entropy ΔS_SYS) of the system showed that the system was exothermic and entropy driven on the overall. The change in molar heat capacity (ΔsysC_P) for the system was also found to be negative and the micellization process of CTABr-AHCl was enthalpy-entropy compensated with the value of compensation temperature (T_c) of 325.65 K.The micelle-lipophilic drug system was found to be thermodynamic spontaneous and feasible at the investigated temperatures and concentrations.

Impact of anthropogenic activities on the physicochemical quality of Oke- Bola Stream, Oyo State, Nigeria

2024-07-10T10:46:13+00:00

The study aimed to determine the impact of anthropogenic activities on the physicochemical quality of the Oke- Bola Stream, Oyo State, Nigeria. Five (5) composite water samples were collected from five (5) stations of the stream. Temperature and pH were tested in situ, then samples were transported to the chemistry laboratory for further analysis using standard methods. The results showed the highest mean temperature in station A (25.1 ^OC), pH in stations C and E (6.73), total acidity in station B (73.0 mg/L), electrical conductivity (EC) (854 μS/cm), total dissolved solid (TDS), salinity, total alkalinity, chloride ion (Cl^-) and dissolved oxygen (DO) in station C (427, 425, 225, 2600 and 15.4 mg/L) respectively. The EC and TDS across the stations were within the WHO (2011) standards (1000 μS/cm, and <600 mg/L). Temperature in station E (24.6 ^OC), pH in stations A (6.26) and B (6.11), total alkalinity in station C (225 mg/L), salinity and Cl- concentration across the stations and DO in four of the stations (A, B, C and E) are not in compliance with the WHO (2011) standards (25-29^oC, 6.5-8.5, 200, 100, 250 and 13-14 mg/L respectively). Pearson correlation revealed a significantly strong association between pH and T. alkalinity (r=0.915). TDS with EC (r= 0.988) and salinity (r=0.992). EC with salinity (r=0.978). T. acidity with DO (r=0.917) p<0.01. The study revealed an unacceptable level of the studied physicochemical parameters in some and across the stations linking to the anthropogenic activities around the stream.

Assessment of some heavy metals and physiochemical parameters of soil samples from Biu, Biu Local Government Area, Borno State, Nigeria

2024-07-10T10:57:32+00:00

Biu is central to the known Biu province which harbors mostly the Pabirs and Buras who considered farming not only as a source of livelihood but as a pride. Cereal and other agricultural products are produced for both commercial and consumption purposes, thus, a lot agrochemicals and other soil amendments are employed to improve harvest. Also, the soil of the area is mostly found either amongst or surrounded by mountains or rocky environment, thus the need to assess level of some heavy metals and physicochemical parameters of the soil samples is critical. Atomic Absorption Spectrophotometer (AA-6800 SCHIMADZO) was used to determine the concentration of the heavy metals in the soil. Determinations of pH, electrical conductivity, cation exchange capacity (CEC) organic carbon, organic matter, calcium, sodium and potassium were carried out using standard methods. The results revealed the concentrations of Mn ranging between 6.45 and 16.98 mg/kg; 5.34 and 14.324 mg/kg Fe; 0.98 and 1.67 mg/kg Ni; 0.19 and 0.916 mg/kg Co; 0.43 and 0.838 mg/kg Cu; 0.326 and 1.269 mg/kg Zn; 0.012 and 0.435 mg/kg Pb; 0.043 and 0.813 mg/kg Cd and 0.02 and 0.80 mg/kg As. The levels of heavy metals in the sampled areas are in the following order Mn > Fe > Ni > Zn > Co > Cu > Cd > As > Pb. The predominant high concentrations of manganese and iron in all the depths for pre- and post harvests soil samples observed from the results could be associated to nature of soil of the area which is mostly found amongst or surrounded by mountains or scattered rocks. It is also clearly observed that the concentration of the heavy metals is higher in the post-harvest compared to pre-harvest, this could be attributed to the use of agrochemicals applied to boost harvest and to control pest. The levels of some physicochemical parameters in soil samples from different agricultural locations during pre-harvest and post-harvest revealed pH values ranging between 5.74 and 6.32; 28.0 and 151.0 (μScm^-1) electrical conductivity; 0.92 and 1.58 % organic carbon; 1.59 and 4.17 % organic matter; 6.21 and 90.9 c.mol/kg CEC; 1.40 and 37.0 mg/kg Ca; 0.12 and 0.26 mg/kg Na and 0.23 and 2.94 mg/kg K. The decrease in heavy metals concentration with increase in depth is in agreement with increase in pH with increase in depth. Low pH increases the solubility and mobility of heavy metals since the mobility and availability of heavy metals are considerably greater in acidic soils than in near neutral or alkaline soils. In this study organic carbon and organic matter are observed to decrease with depth both in the pre-harvest and post-harvest, high organic matter content helps in high retention capacity of many pollutants. The cation exchange capacity (CEC) is found to decrease in depth with rise in pH values. Levels of Na, Ca and K detected in the soil are within the safe limit set by FAO, however, the heavy metals were found to be above the limit.

Synthesis and characterization of zeolite sourced from rice husk lignocellulosic waste ash

2024-07-10T16:13:25+00:00

Rice husk, typically deemed a byproduct in the rice industry, presents a promising avenue for the production of valuable materials including zeolites, which are highly sought-after as crucial adsorbent support materials. This study intricately focuses on the synthesis of zeolites utilizing rice husk ash (RHA) as the SiO₂ source with a Fourier-Transform Infrared (FTIR) analysis guided optimized addition of aluminum from external sources. The produced zeolite, as evidenced by the FTIR spectrum, showcases distinct functional groups associated with zeolite formation, notably the -O-H band at 2851 cm−1 and the bending vibration of adsorbed water molecules at 1659 cm⁻¹. Prominent Si-O-Si, Al-O, and Si-O-Al functional groups absorbed further validate zeolite framework formation. Employing a straightforward method involving alkaline extraction and acid precipitation, the study successfully yields pure silica xerogel from this waste, minimizing mineral contaminants. The resulting xerogel demonstrates 91% silica content and 2.6-4% moisture. Subsequent water washing proves effective in further reducing mineral content (Na < 200ppm, K < 400ppm). X-ray Diffraction (XRD) analysis of the zeolites reveals the amorphous nature of silica xerogels, emphasizing their heightened activity for zeolite Y and P production. This comprehensive investigation not only underscores the potential for converting rice husk waste into valuable materials but also contributes to sustainable and efficient utilization practices.

Mnium hornum Hedw moss as bioindicator of atmospheric pollution of heavy metals in the University of Lagos, Akoka Campus

2024-07-10T16:28:28+00:00

This study investigated the presence of heavy metals pollutants in the University of Lagos, Akoka campus using the moss (Mnium hornum Hedw.) as a bioindicator. Samples of M. hornum. were collected in 2019 from four different locations within the University of Lagos campus: Faculty of Engineering (FE), Lagoon Front (LF), Main Library (ML) and Akintunde Ojo Library (AKT). A control sampling was done at First Estate, Amuwo-Odofin LGA (CL). The concentrations of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) were determined using the Atomic Absorption Spectrophotometer (AAS). Results confirmed the presence of heavy metals in the following order Fe > Zn > Mn > Cu > Pb > Ni > Co > Cr > Cd. The concentrations of the examined heavy metals across the locations were lowest in CL except Ni which was lowest in FE and LF (0.03mg/kg). While there were no significant differences in the concentrations of Cd, Co, Cr, Cu, Mn, Ni, and Pb among the locations, both Fe (66.00mg/kg) and Zn (64.33mg/kg) were significantly higher in ATK than in the other locations. The contamination factor suggests that ML (C2), FE (C3) and LF (C3) were moderately contaminated while AKT (C5) was highly contaminated. The index of geo-accumulation revealed that FE (I_geo4) and ML (I_geo4) are moderate to severely polluted, LF (I_geo5) was severely polluted while AKT (I_geo7) was extremely polluted with the assayed metals. The difference in the occurrence of anthropogenic activities was believed to be the major factor responsible for the variations in the concentration of heavy metals accumulated by the mosses.

Synthesis, characterization and heavy metal removal efficiency of β- cyclodextrinethylamine inclusion complex

2024-07-10T16:48:47+00:00

Environmental contamination with heavy metals is one of the main concerns on a global scale and the risk related to heavy metal exposure in water as a serious threat to human health. Removal of heavy metal contaminants from water can be done in many ways using conventional and membrane techniques. This study synthesized, characterized and investigated the removal efficiency of inclusion complex of β – cyclodextrinethylamine in the removal of some heavy metals in contaminated water samples obtained from Makurdi, Benue State, Nigeria. β– cyclodextrinethylamine metal complex was prepared and characterized by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Fourier Transformed Infrared Spectroscopy (FTIR) while the heavy metal concentrations for the removal efficiency was determined using Atomic Absorption Spectroscopy (AAS). The results indicated that the removal of heavy metals was efficient in the study areas with the highest average percentage removal efficiency and a trend of Cu = Co (99.85 %) > Zn (99.80 %) > Ni (99.75 %) > Cd (99.1 %) obtained in Tse – Chivir sample area while the efficiency of heavy metal removal obtained from Joseph Sarwuan Tarka University, Makurdi (JOSTUM) showed the order of Ni = Co(99.8 %) > Zn = Cu > Cd (99.5 %). Indicating that the inclusion compound can be used for effective removal of heavy metals in contaminated solutions and purification processes in water treatment.

Chemical composition and toxicological risk assessment of Potentially Toxic Elements (PTEs) in a commercially available alcoholic bitters

2024-07-10T17:06:08+00:00

This study aimed at determining the Chemical composition and Toxicological Risk Assessment of Potentially Toxic Elements (PTEs) in a commercially available Alcoholic Bitters. Samples of Confam bitters were purchased and transported to the laboratory for analysis using the standard method of the Association of Official Analytical Chemists (AOAC) and the toxicological risk assessment was estimated using predictive modelling of the United State Environmental Protection Agency (US EPA). The result obtained indicates that the bitters contain compounds such as Bactobolin (2.02%), 3-Methoxyamphetamine (1.10%), Propanamide (3.04%), Methylpent-4- enylamine (1.10%), Diisopropyl phthalate (35.62%), N, N'-Bis (3-aminopropyl) ethylenediamine (1.95%), Didodecyl phthalate (2.29%), n-Hexadecanoic acid (8.17%), Metaraminol (2.98%), Methyl octadec- 11-enoate (4.53%), Linoelaidic acid (8.70%), Octadecanoic acid (3.30%) and Octadecyl prop-1-en-2-yl carbonate (1.45%). The result also indicates that the concentration of Zn (1.26 mg/l), Cu (0.22 mg/l) and Ni (90.16 mg/l) were within the WHO (2011) standard (3.00, 2.00 and 0.02 mg/l) respectively, while Pb (0.03 mg/l), Cd (0.005 mg/l), Mn (3.85 mg/l) and Cr (0.66 mg/l) were higher than the WHO (2011) standard (0.01, 0.003, 0.05 and 0.05 mg/l) respectively. Toxicological risk assessment revealed that the children population is more susceptible to PTE exposure in the bitters. Therefore, disapproving children exposure to the bitters. Furthermore, Mn and Zn were the most dosed PTEs of exposure. Hazard Quotient (HQ) revealed that the values for the PTEs are less than 1, while carcinogenic risk values are less than 1 × 10^–6, suggesting a nonsignificant non-carcinogenic and carcinogenic risk respectively for the human population. In conclusion, the alcoholic bitter contains compounds of excellent pharmacological effects, a potentially hazardous compound and high concentrations of some PTEs of public health concern, more so other brand of bitters should be monitored.

Synthesis, characterization and in silico studies of some 2-amino-4,6- diarylpyrimidines derived from chalcones

2024-07-11T05:05:21+00:00

Pyrimidine derivatives have garnered substantial research interest over the past decades. This is largely due to their wide range of biological activities as antiviral, diuretic and antitumor agents, as well as their potential therapeutic application in ameliorating several degenerative diseases. In this study, 2-amino-4,6- diarylpyrimidines were synthesized from their respective 1,3-diphenylprop-2-en-1-one (chalcone) precursors. The chalcones were condensed with guanidine carbonate by refluxing in dimethylformamide for 4 hours at 160^oC to obtain the following compounds: 4,6-diphenyl-pyrimidin-2-ylamine (PAA₁), 4-(4-nitro-phenyl)-6- phenylpyrimidin-2-ylamine (PAA₂), 4-phenyl-6-(3,4,5-trimethoxy-phenyl)pyrimidin-2-ylamine (PAA₃) and 4-phenyl-6-(3,4,5-trimethoxy-phenyl)pyrimidin-2-ylamine (PAA₄). TLC analysis was used to monitor the purity of the synthesized compounds, and their melting points were determined using the open capillary method with a Kofler Electrothermal melting point apparatus. They were characterized using IR, ¹H-NMR, ¹³C-NMR and GC - MS. The biological activities of the title compounds were predicted using the Gaussian 16 software suite-36 (for full geometry optimization in chloroform and gas phase) and the SwissADME web tool for lipophilicity and hydrophilicity. The compounds were obtained in good yield, and the characteristic N-H stretch of the -NH₂ group (free and H-bonded) was observed at 3503, 3380 cm^-1 (PAA₁); 3492, 3317 cm^-1(PAA₂); 3194, 3309 cm^-1 (PAA3); and 3466, 3313 cm^-1(PAA4). The amino protons showed a broad peak between 4.47 – 5.31 ppm while the characteristic C2 and C5 of 2-aminopyrimidines resonated at 105.34 and 163.03 ppm respectively. The logP values revealed that the lipophilicity of the compounds decreased in the order: PAA₁< PAA₂< PAA₃< PAA₄. The computations on the optimized geometry established the possible application of the compounds in the synthesis of modern pharmaceuticals.

Heterogeneous transesterification of extracted oil from sweet orange (Citrus sinensis) seed using modified eggshell as catalyst

2024-07-11T05:18:41+00:00

The environmentally sustainable production of biodiesel is important for providing a renewable alternative transportation fuel and a fuel for diesel engines. This research evaluates the use of low-cost catalysts derived from waste materials (eggshell) for converting triglycerides in seeds oil (sweet orange seed oil) into biodiesel composed of fatty acid methyl esters. The oil extracted was first characterised for its physicochemical parameters viz; yield (38.88 %), moisture content (6.50 %), relative density (0.89 g/cm³), specific gravity (0.90), refractive index (1.46), iodine value (55.80 gI₂/100 g), acid value (5.64 mgKOH/g), free fatty acid (2.82 mgKOH/g), saponification value (179.90 mgKOH/g), and viscosity (0.04 Pa. S). The parameters were within the AOAC (1990) standard except for moisture content and saponification values which were slightly below while acid and free fatty acid values were slightly higher than the AOAC (1990) standard. Further treatment of the oil for suitability for transesterification for biodiesel production was carried out. The GC-MS analysis of the oil shows that triglycerides and other organic functional groups were evident. The eggshells were calcined (750°C) and modified with H₂SO₄ (20 %) to improve its surface for catalytic activity. Transesterification conditions were; oil to methanol ratio of 1:9, reaction time of 2 h and temperature of 65°C while the catalyst dosage was 10 %. The physicochemical parameters of the biodiesel were obtained to be; yield (39.03 %), refractive index (1.47), acid value (1.12 mgKOH/g) and free fatty acid (0.56 mgKOH/g) were all within the accepted range specified by American Society for Testing and Materials, (ASTMD6751). The GC-MS result of the separated biodiesel showed different methyl esters implying that, there was conversion of the triglycerides to methyl esters. Thus, orange seeds and eggshells can be harnessed for biodiesel production.

Solvent- free synthesis, characterization, thermogravimetric and antimicrobial studies of Cu(II) complex with imine ligands

2024-07-11T05:28:09+00:00

Grinding was used as a solvent-free synthetic approach to prepare the ligand (L₁) from 2, 4-Dinitrophenylhydrazine and 3-Hydroxybenzaldehyde with N-(3-hydroxybenzaldehyde)-p-fluoroaniline ligand (L₂) and their Cu(II) complex. Melting point, solubility test, molar conductance, UV-Vis, and IR spectrophotometry were used to characterize these compounds. Thermogravimetric analysis (TGA) was used to investigate the thermal stability of the ligands in conjunction with their Cu(II) complex. Coats-Redfern's approximation methods were used to compute the energy of activation (Ea), entropy of activation (ΔS^o), free energy of activation (ΔG), enthalpy of activation (ΔH^o) and collision frequency (Z). Using scanning electron microscopy (SEM), the surface morphologies of the solid compounds were captured. The particle sizes of the ligands and the metal complex were measured using a particle size analyzer at a diffraction angle of 10.9°. The newly synthesized compounds were screened for their antimicrobial activities. Melting points of the synthesized compounds were in the temperature range of 188 - 194℃ showing that they were fairly stable; solubility in nonpolar solvents and molar conductance values (5.6 – 14.10 Ω/cm^-2) indicates that the ligands and the complex are non-electrolytic in nature. Comparing the electronic spectra of the free ligands with that of the complex revealed a shift from lower to higher frequencies which confirmed the chelation of the ligands with Cu(II) ion. The FTIR spectra showed bidentate ligands which coordinated through nitrogen atom of the imine group and the deprotonated oxygen atom of the hydroxyl group. Thermal results of the ligands revealed absence of water crystals while those of the complex showed two molecules of water. The kinetic parameters revealed that the decomposition reactions of these compounds was a first order reaction and the activation energy (kJmol^-1) were 54.05, 25.59 and 25.95 for HL₁, L₂ and Cu(II) complex respectively, implying that HL₁ require extra energy to form activated complex. The collision frequencies were 7. 06 × 10¹⁶, 4. 01 × 10⁴ and 7. 6 × 10⁴ _s^-1 for HL₁, L₂ and Cu(II) complex, which signifies extra spaces in HL₁ and Cu(II) complex than L₂. Positive values of ΔG of the compounds was an indication that the decomposition was non-spontaneous while positive ΔH^o showed that enthalpy was the driving force for the decomposition process. Negative entropy of activation implied that the degree of disorderliness of the products formed by bonds dissociation was lower than that of the reactants. The Schiff base ligands revealed weak activity against the test bacteria and inactivity against the test fungi while the metal complex significantly increased antimicrobial sensitivity against the test microbes.

Distribution and enrichment of trace metallic elements in the sediments of the Kaswa/Mahagi thermal waters of (North-East of the Democratic Republic of the Congo)

2024-07-12T05:09:54+00:00

Sediments contamination by trace metals constitutes one of the major problems in aquatic environments worldwide. This work aimed to study the distribution and evaluate the level of contamination of trace metallic trace elements (TMEs) in the sediments of the thermal waters of Kaswa/Mahagi in the North-East of the Democratic Republic of Congo. The indexes and statistics method allowed the assessment of sediment quality. Six surface sediment samples, collected in January and April 2022, were analysed using the FAAS Perkin Elmer brand-Analyst 400 spectrometer. The TMEs identified were lead (Pb), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), cadmium Cd) and nickel (Ni), the abundance being Mn>Zn>Pb>Fe> Cu>Cr>Ni>Cd. The concentrations of Cd (0.83±0.14 μg/g) and Pb (43.22±5.76 μg/g) were beyond the standards considered. The geo-accumulation index (Igeo) and enrichment factor (EF) showed moderate pollution of the sediments and serious enrichment in Cd (2<Igeo<3, 10<EF<25), enrichment of anthropogenic origin (FE>1.5). The sites were unpolluted to slightly polluted and moderately enriched in Pb, Cu and Zn (Igeo<1, 1<FE<3). Polymetallic toxicity revealed a considerable degree of contamination (12<DC<24) and a progressive deterioration of sediment quality (Pollution load index-PLI>1) in all sites.

Determination of some potentially toxic elements in indoor dust particles from selected medical laboratories in Kano Metropolis

2024-07-12T05:18:46+00:00

Indoor dust particles act as a medium for toxic elements accumulation. The risk of exposure to metal contaminated dust particles is of great concern. In this research, some potentially toxic elements (PTEs) in indoor dust samples from selected laboratories in Kano metropolis were examined. The samples were collected from different locations (doors, windows, reagent-shelves, fans, and air conditioners filters) to produce a composite representative sample. The samples were analyzed for Si, Co, Mn, As, Ni, Cr, Pb, Cd, Cu, and Zn using a Microwave Plasma Atomic Emission Spectroscopy (MP-AES). Results obtained revealed that the levels of these elements determined in the dust samples were significantly different at (P<0.001). The levels of the elements Zn, Cd, Pb, Cr, As, Cu, Ni, Co and Mn in the various samples analyzed were all below the permissible limit established by World Health Organization (WHO). However, all the laboratories had high concentration of Si. This study may provide baseline data for monitoring and/or controlling air pollution in the laboratory premises.

Quantitative assessment and toxicological study of sunset yellow dye (E110) as an additive in some beverages consumed in Katsina Metropolis, Nigeria

2024-07-12T05:23:37+00:00

Synthetic dyes have been used in food, beverages and pharmaceuticals for consumer attractions. The dyes are usually added to substrates to replace the natural colorants that could be lost during processing or to prevent variations in the color of the final products. Unfortunately, the dyes have been reported to cause many health related issues. However, there is a need to constantly monitor the amount of such colorants in our food and beverages. Empirically, the acute toxicity was carried out to examine the LD₅₀ (acute toxicity) of the Sunset yellow (E110) (analyte) dye using Wistar albino rats in accordance to the administered doses per body weight of the tested animals, as well as quantitative analysis of the targeted analyte in some beverages consumed in Katsina metropolis, Nigeria. The result of the LD50 values for the Sunset yellow dye standards estimated to be more than 5000 ppm per body weight of the tested animals. Thus, there were some few changes in the animals’ behavioral attitudes, which varies according to the concentration of doses administered and the results produced no mortality at the given doses range of 50 to 5000 ppm after administering the dye standards. The quantitatively analyzed samples contained 49.536 ± 0.004, 109.785 ± 0.130, 108.975 ± 0.075, 46.140 ± 0.018 and 42.059 ± 0.009 ppm of the Sunset yellow dye, respectively in samples A, B, C, D and E. This justifies the safe consumption of sample A, D and E of the analyzed beverages since the concentrations of the Sunset yellow dye in them were below the maximum permissible limits of 50 ppm as supported by OECD (Guideline for the Testing of Chemicals, Acute Oral Toxicity–Acute Toxic). Although, excessive consumption of such beverages containing the dye additives could lead to continuous accumulation of the dye in the body tissues beyond its maximum permissible limits, that may result in health issues at long run that include different forms of cancers and also provoking allergic reactions such as asthmatic symptoms in the body.

Determination of some heavy metals and selected phenolic compounds in commercial honeys obtained from Northwestern States of Nigeria

2024-07-12T05:32:10+00:00

Natural honey is one of the highly needed products because of its exclusive, high nutritive and medicinal properties, it is among the most adulterated products globally. Honey adulteration is a global concern, it has negative effects on the nutrition and health of consumers and has become a common practice because of the high demand and limited availability of the product. This research aims to evaluate the heavy metals concentrations and the phenolic compounds in honey samples obtained from local sellers and compare the levels with honeys from credible beekeepers in Northwestern states of Nigeria (Kano, Kaduna, Jigawa, Katsina, Sokoto, Zamfara and Kebbi) in order to detect possible adulteration of the products. Results indicated that most of the heavy metals detected Cd (ND-0.10±0.16 μg/g), Pb (0.20±0.11-1.62±1.60 μg/g), Ni (0.03±0.04-0.53±0.46 μg/g), Cu (0.47±0.23-2.61±2.11 μg/g), Zn (5.75±4.04-7.63±131.74 μg/g) and Fe (6.74±1.92-61.43±98.12 μg/g) in honeys from local sellers were above the permissible range set by the International Honey Commission (IHC) and NAFDAC while the levels in samples obtained directly from beekeepers closely complied with the standards. The non-compliance of the metal levels with IHC standards in locally sold honeys could possibly be due to adulteration of the products using metal-contaminated adulterants. However, lower values were recorded for Phenolic compounds: flavonoids (154.5- 521.7 mg/kg) and Phenolic acids (399.6-1075.0 mg/kg) in most of the honeys from local sellers except in honeys from Zamfara state. Generally, results from this study indicate that large percentage of the honey products sold locally in the Northwest Nigeria are suspected to be adulterated mostly with sweeteners while honeys obtained directly from beekeepers were found to agree with IHC standards. It is therefore recommended that pure honeys should be obtained directly from credible beekeepers.

Impact of dumping faecal sludge on the microbiological quality of Funa River Water in the City of Kinshasa, the Democratic Republic of Congo

2024-07-12T05:40:34+00:00

The Funa river in the city of Kinshasa Democratic Republic of Congo is transformed into a wild dump and in its downstream part, into a receptacle for septic tank sludge coming from the city's houses, buildings, hospitals etc. The aim of this study was to investigate Funa river water and determine its pathogenic pollutant load coming from dumped faecal sludge. A survey carried out from October 2018 to September 2019 during the dry and rainy season on the identification of pathogenic and non-pathogenic germs made it possible to highlight the microbiological quality of the water. Results obtained showed that on average 5197 m3 of faecal sludge was dumped into this river. The germs identified were Escherichia coli (22,566.6-30.103 CFU/100 mL), Enterococcus ssp (18.333,3–18 333.3 UFC/100 mL) Salmonella (22.566,6–30103 UFC/100 mL) and Shigella (366,6 – 800 UFC/100 mL) in significant numbers. Thus, the dumping of faecal sludge into the Funa river represents a serious public health risk considering the number of pathogenic microorganisms identified in the water. The protection of this river is a necessity in order to preserve the health of the local population.

Synthesis and spectroscopic determination of Cu(II) and Co(II) metal complexes with pthalamide and 2,4-dinitrophenylhydrazine

2024-07-12T05:53:17+00:00

Copper (II) and Cobalt (II) metal complexes were derived from the synthesis of pthalamide and 2,4-dinitrophenylhydrazine. Both synthesized metal complexes were found to be soluble in acetone and butanol, slightly soluble in n-hexane and propan-1-ol, partially soluble in ethanol and methanol, and insoluble in water. The synthesized Cu (II) and Co (II) metal complexes were characterized by IR, Uv-Vis, TGA, XRD and Magnetic Susceptibility. The IR spectral bands observed for both Cu (II) and Co (II) metal complexes are3287.5cm-1 (N-H) stretch, 708.19 cm-1 (N-M) stretch, 1729.5cm-1 (C=O) stretch, 1610.20cm-1 (C=C) stretch, 1043.65cm-1 (N-N) stretch and 3101.1cm-1 (C-H) ar-stretch, 1334cm-1 (NO2) stretch for Cu (II) complex while 3145.9cm-1 (C-H) ar-stretch, 1341cm-1 (NO2) stretch for Cu (II) complex. The electronic transitions found from the Cu-Complex were 236.95nm (n- π*) assigned to C=O, 207.29nm (π- π*) assigned to C=C, 400.82nm (n- π*) assigned to NO2 and a band of 472nm assigned to the LMCT. The Co-Complex also has bands at 237.8nm (n-π*) assigned to C=O, 215.58nm (π- π*) assigned to C=C, 401.82nm (n- π*) assigned to NO2 and 465nm assigned to the LMCT. The decomposition of the synthesized complexes were to be 205oC and 202oC for Cu-Complex and Co-Complex respectively. The thermal decomposition of the complexes were also observed by TGA. The XRD results showed that the Cu-Complex is crystalline while the Co-Complex is amorphous and the Magnetic Susceptibility of the complexes was also confirmed for their paramagnetic nature.

Mechanochemical synthesis, structural characterization, and antimicrobial evaluation of tri-nuclear Co(II), Ni(II), and Cu(II) complexes with vanillin-L-Leucine Schiff base

2024-07-12T10:19:43+00:00

In this paper, a binucleating Schiff base derived from vanillin and L-Leucine and its Co(II), Ni(II), and Cu(II) tri-nuclear metal complexes were synthesized via a mechanochemical route as an alternative to solution-based methods. The compounds were characterized by elemental analysis, ESI-mass spectrometry, infrared spectroscopy, thermogravimetric analysis (TGA), solubility screening, conductivity and magnetic measurements. The FT-IR spectroscopic data provides evidence for the presence of imine linkage between Lleucine and vanillin resulting in the formation of the Schiff base. In addition, the IR spectral data indicate that the C=N stretching band of the Schiff base shifts from 1673 cm-1 to lower frequencies in the range of 1668 to 1629 cm-1 upon coordination with Co(II), Ni(II), and Cu(II) ions. This shift confirms the formation of metalligand bonds. The Schiff base behaves as a tridentate dibasic ligand and binds to metal ions via the phenolic oxygen, imine nitrogen and carboxylic oxygen (O,N,O) resulting in trinuclear complexes. ESI-MS spectra showed m/z = 342.02, 1208.16, 1131.21 and 1412.87 corresponding to singly charged adduct ions, which confirms the molecular weight of the Schiff base and the trinuclear Co(II), Ni(II) and Cu(II) complexes respectively. Data from thermogravimetric analysis (TGA) confirms the presence of both coordinated water and water of crystallization in the metal complexes. The molar conductivity values ranging from 12.04 to 21.68 Ω- 1·cm²·mol⁻1 for the tri-nuclear Co(II), Ni(II), and Cu(II) complexes suggest that the tri-nuclear metal complexes are non-electrolytes. The magnetic moments for the tri-nuclear Co(II), Ni(II), and Cu(II) complexes were found to be 4.51, 3.67, and 1.99 BM, respectively, which suggests paramagnetic metal centers. The percentage yield of the synthesized compounds was found to be in the range of 88.61-94.66%. Anti-bacterial and anti-fungal activities of the Schiff base and its corresponding metal complexes were investigated in vitro using the disc iffusion method against Staphylococcus aureus, Streptococcus pneumoniae, Salmonella typhi, Escherichia coli, Trichophyton tonsurans and Trichophyton rubrum. The results of the anti-microbial assay showed that the metal complexes are more active compared to the Schiff base.

In vitro evaluation of the phytochemical composition and kinetics study of Ficus sur leaf extracts in the inhibition of α-Glucosidase and α-amylase

2024-07-12T10:27:27+00:00

In Nigerian indigenous medicine, Ficus sur finds usage in a wide range of conditions, including diarrhea, anemia, wounds, stomach issues, infertility, peptic ulcers, and gonorrhea. The research aims to evaluate the phytochemical composition and assess the inhibitory capacity of α-glucosidase and α-amylase leaf extracts of F.sur. The leaves of F. sur were extracted successively by maceration with acetone, ethanol, methanol, and aqueous. Established methods were adopted to identify the phytochemical and polyphenolic compositions of the herbal extracts; the extracts' α-amylase, as well as α-glucosidase inhibitory capacity utilizing the Lineweaver-Burke plot to identify mechanisms of inhibition by the enzyme, were further explored. The findings of the phytochemical analysis showed that the liquid extracts of ethanol and methanol contained the greatest quantities of saponin, whereas the extracts of acetone and water had none. Extract from ethanol had a great amount of phenolics (131.86 mg gallic g^-1) when compared with methanol (126.12 mg gallic g^-1), acetone (92.35 mg gallic g^-1), and aqueous extract (48.68 mg gallic g^-1). The hypoglycemic results showed that the ethanol extract had much higher inhibition of α-glucosidase (IC₅₀ = 0.41 mg mL^-1) and mild inhibition of α-amylase (IC₅₀ = 1.39 mg mL^-1). According to a Lineweaver-Burk plot analysis, ethanol extract inhibited the two enzymes in noncompetitive and competitive ways. F. sur leaf extract's high saponins and phenolic content substantiate its hypoglycemic potential.

Assessment of some potentially toxic/essential elements in Hibiscus sabdariffa L. from selected gardens in Kano Metropolis

2024-07-12T10:35:59+00:00

Toxic elements have adverse effects on human health and therefore potentially toxic elements (PTEs) contamination in food deserves special attention. The research assessed the concentration of potentially toxic/essential elements in Hibiscus sabdariffa L. calyx sourced from five different gardens in Kano metropolis, Nigeria, using Atomic Absorption Spectrophotometry (AAS). Proximate analysis of the calyxes sample yielded 11.8% Ash content, 1.8% fat, 13.9% crude fibre, 4.2% protein, 7.1% moisture and 62.5% carbohydrate. The result of the mineral composition (essential elements) yielded the following in mg/kg of sample: K (106.5±0.2), Na (68.2±0.1), Mg (102±2.0), Ca (4.2±0.1), Fe (7.1±0.3), P (35.5±0.8).The results indicated that the concentrations of targeted PTEs in different gardens were in the range in mg/kg: Cd (0.217±0.039 - 0.020± 0.005), Ni (0.213±0.054 - 0.012± 0.001) and Pb (0.485±0.085- 0.163± 0.024). Both Cd and Ni were within acceptable limit of WHO/FAO in all samples except Pb which was above the limit set by WHO/FAO. There should be adequate monitoring of toxic metals in Hibiscus sabdariffa L. samples sourced from the gardens to prevent toxicity into the food chain causing bioaccumulation.

Photocatalytic studies of methylene blue dye degradation on synthesized Ni-doped strontium zirconate perovskite nanoparticles

2024-07-12T10:41:11+00:00

Perovskite oxides have been recognized as highly potent catalysts for photocatalytic water decontamination due to their potential to capture solar energy and drive catalytic reactions. In this report, Ni doped strontium zirconate perovskite photocatalyst nanoparticles was synthesized using simple method with low production cost was applied in visible light irradiation for the photocatalytic degradation of a model organic pollutant in aqueous medium. The photocatalyst was synthesized successfully using sol-gel Pechini method and annealed at 800 ℃ for 2 h. The sample was characterized using XRD, FESEM, EDX FTIR and UV-visible spectrophotometric techniques. The crystallite size ranged between 23.74 and 33.18 nm according to Scherrer equation and Williamson-Hall methods with a dislocation density, lattice strain, and microstrain of 1.77, 1.4 and 3.4 (x 10^-3) respectively. The sample exhibited smooth surface with no agglomeration. The composition of the perovskite indicated the presence of Sr, Zr, Ni and oxygen in their atomic weight. Metal-oxygen vibration was located at 648.55 cm-1 with traces of adsorbed atmospheric CO₂ and H₂O on the catalyst surface. The catalyst exhibited optical band gap energy of 5.15 eV. The photocatalytic activity was evaluated by the degradation of Methylene blue (MB) under simulated light at 420 nm. Photodegradation was highest in light irradiated reaction compared to dark conditions. The effects of the amount of catalyst, initial concentration of MB dye irradiation time and solution pH on the degradation and removal efficiency of the pollutant was investigated. Adsorption capacity was found to increase with increase in initial adsorbate concentration and irradiation time in acidic pH. In order to investigate the efficiency of MB dye adsorption on strontium nickel zirconate (SNZ) photocatalyst, pseudofirst order (PFO), pseudo-second order (PSO), Elovich and Intra-particle diffusion (IPD) kinetic models were evaluated. The adsorption kinetic was found to follow pseudo-second order model. The graphical correlation of equilibrium data were analyzed by Langmuir, Freundlich, Dubinin-Radushkevich (D-R), Temkin, Flory- Huggins and Redlich-Peterson models by using linear regression technique. The data were best represented by the Langmuir isotherm yielding maximum monolayer adsorption at 30 ℃ with a favorable condition (RL < 1). The adsorption process was found to be exothermic and spontaneous. Therefore, Sr(Ni₀.₁₀Zr₀.₉₀)O₃ nanoparticles can be used as photocatalyst for remediation of wastewater containing organic pollutants.

Analysis of selected heavy metals and physicochemical properties of irrigation water and soil from Warwade Dam, Dutse LGA, Jigawa State

2024-07-12T10:59:15+00:00

This research examines the physicochemical characteristics and concentrations of selected heavy metals in irrigation water and soil from Warwade Dam, Dutse LGA, Jigawa State. The World Health Organization (WHO) guidelines are used in this research to compare the results obtained to assess if the water is suitable for agricultural use, given the significance of water quality for soils, crops, and the environment. According to the analysis, all the farms had mildly acidic pH values, with Farm A having the least acidic readings. While manganese (Mn) was noticeably high in Farm B, elevated amounts of lead (Pb) was identified in Farms A and C, surpassing the WHO allowable limits. The suggested threshold for cobalt (Co) concentration was not exceeded. The variations in temperature, turbidity, and total dissolved solids (TDS) among the samples indicate the impact of both man-made activities and natural processes. High concentrations of Pb and Mn can be harmful to health, which emphasizes the need for routine testing and efficient water treatment techniques to protect the environment and the general public's health. These results of this study highlight how urgently pollution control measures must be put in place to save the environment and maintain the region's agricultural output.