DEPARTMENT OF CHEMISTRY

The study focused on the extraction, phytochemical screening, isolation, and characterization of Hibiscus Sabdariffa. The cold extraction was conducted to extract the plant sample using methanol as solvent. The crude extract was concentrated in a rotary evaporator. A portion of the extract was screened for phytochemicals while the other portion was subjected to vacuum liquid chromatography (VLC) , using solvent systems of varying polarity ;from Hexane, Ethyl acetate , Methanol ,and Butanol of increasing polarity respectively .A Brown precipitate was obtained after the concentration of Butanol extract and characterization was done by High Performance Liquid Chromatography (HPLC). Saponins, alkaloids, and terpenes were detected. However, from the HPLC myrtilin, Linalool, lycopene, where present amongst others. The study shows that H. Sabdariffa contains useful phytochemicals which are implicated as medicinal uses.

Chemical industries increasingly rely on catalytic processes, and more than 90% of large scale chemical transformations depend on catalysts. Some of the commonly used homogeneous catalysts in Fridel Crafts alkylation reaction are; BF3, H2SO4, HF, AlCl3. Though, readily available at low cost, they have several limitations and these include toxicity, difficulty in separation and recovery and disposal problems. These limitations have intensified the demand for sustainable, efficient, and environmentally benign heterogeneous catalysts. This study focuses on the development of metal-doped coconut-shell biochars as robust heterogeneous catalysts for the Friedel Crafts benzylation of toluene. Biochars derived from the coconut shell produced at different pyrolysis temperatures (350, 400, 450, 500, 600 and 700 °C) were characterized in terms of their physicochemical and textural properties, surface oxygen functional groups and surface morphology using standard methods. The coconut shell biochar (CSB) sample with the optimal textural properties (CSB450) was then co-pyrolysed with Fe³⁺, Zn²⁺, and Fe³⁺/Zn²⁺ ions to produce metal doped biochars (Fe³⁺ - doped, Zn²⁺- doped, and Fe³⁺/Zn²⁺-doped biochar). Central Composite Design (CCD) of the Response Surface Methodology (RSM) was employed to optimize the process variables (metal loading, pyrolysis temperature and pyrolysis time) for the co-pyrolysis reaction. Similarly, RSM was used to optimized the process variables (mole ratio of toluene: benzyl chloride (T:BC), reaction temperature and reaction time) on benzyl chloride conversion to benzylated toluenes with the metal doped biochars. RSM-derived optimal conditions resulted in enhanced specific surface areas of 2098.04 m2 .g-1 for the Fe³⁺-doped biochar, 1721.40 m2 .g-1 for the Zn²⁺-doped biochar, and 2124.5 m2 .g-1 for the Fe³⁺/Zn²⁺-doped biochar. Compared with the pristine biochar (CSB450), the metal doped biochars (MBCs) showed improved physicochemical properties and textural properties. In addition, surface elemental analysis confirmed the successful incorporation of the Fe (10.09%), Zn (5.17%) and Fe/Zn (9.44/6.51%) on the MBCs. The results of the conversion process showed that the reaction temperature, mole ratio, and reaction time significantly affected benzyl chloride conversion with the metal doped biochar. Three novel models were developed for benzyl chloride conversion process. From the models, we predicted optimized process conditions; optimum benzyl chloride conversion of 93% was found for Fe3+/Zn2+ - doped biochar, with values of 87 and 81% for the Fe3+ - and Zn2+ - doped biochar respectively. This research established metal doped coconut shell biochar as an effective, low-cost, and environmentally friendly heterogeneous catalysts for organic transformations, presenting a viable alternative to conventional corrosive and non-recyclable catalysts in industrial alkylation processes.

This study was aimed to examine suitability of Dangara middle layer clay as an adsorbent for the removal of vanadium ions. variable parameter such as adsorbent dosage, initial concentration, contact time, pH and temperature were at moderate level such that they can affect the removal of vanadium ions. For pH, it was observed that the % removal was increases with an increasing in pH. The optimum % removal was obtained from 79.39 at pH 9, and the lower % removal was obtained at 70.50 from pH 3. For adsorbent dosage it was discover % removal increases with an increasing in adsorbent dosage, the optimum % removal was obtained 82.15 at 1g and the lower % removal was obtained from 69.28 at 0.2g. for initial concentration there an increases in percentage removal with an increasing in initial concentration the optimum percentage removal was obtained at 86.91 at 50g and lower percentage removal was obtained from 81.56 at 10g. for contact time it was discover there is increases in percentage removal with an increasing in contact time, the optimum percentage removal was obtained from 80.52 at 50mins And the lower percentage removal was obtained at 76.07 at 10mins also there is an increases in percentage removal with an increasing in temperature, optimum percentage removal was obtained at 80ᴼC (81.07) and lower percentage at 40ᴼC (78.67). The efficiency determination (r2) fitted for both langmuir and freundlich. For Langmuir isotherm it was discover that the efficiency determination (r2) obtained was 0.999 and efficiency determination for freundlich was 0.995 Maximum adsorption capacity calculated for Langmuir was 0.345mg/g why the freundlich constant obtained was o.457. The Langmuir model was found to better described the adsorption behavior. Overall, the clay is not considered competent enough as an adsorbent for the removal of vanadium ions from aqueous solution because of low adsorption capacity calculated to be 0.345mg/g. Modification of the surface of the clay could improve its adsorption capacity.

This study aimed to determine the levels of heavy metals in pumpkin, bitter, and water leaves to evaluate their potential health risks and nutritional quality. Samples of the three types of leaves were collected from different locations in Evidence ISIOHOR OVIA NORTH EAST LGA, Benin City, Edo state and subjected to heavy metal analysis using established analytical methods. The concentrations of heavy metals, including iron (Fe), copper (Cu), manganese (Mn), lead (Pb), cadmium (Cd), and zinc (Zn), were determined and compared to international standards and guidelines. Results revealed varying levels of heavy metals in the leaves, with differences observed among the three types. Pumpkin leaves exhibited elevated levels of iron, manganese, and zinc, while bitter leaves showed higher concentrations of copper. Water leaves displayed relatively lower levels of heavy metals compared to the other two types. However, all three leaf types had concentrations of heavy metals below regulatory limits, except for lead in water leaves, which exceeded the permissible level. These findings highlight the importance of monitoring heavy metal levels in leafy greens, as they can serve as indicators of environmental contamination and potential health risks. While the concentrations of heavy metals in the studied leaves were generally within safe limits, the presence of elevated lead levels in water leaves suggests the need for further investigation and mitigation measures to ensure food safety. In conclusion, this study provides valuable insights into the heavy metal content of pumpkin, bitter, and water leaves, contributing to efforts aimed at promoting food safety and nutritional quality. Continued monitoring and research in this area are essential to safeguarding public health and enhancing the sustainability of food production systems.

The concentrations of heavy metals; lead (Pb) and chromium (Cr) in cow offals (liver, kidney, intestine, and tripe "shaki") were investigated. A total of twelve samples were collected from three different abattoirs in Ovia North-East, Benin City, Nigeria: The University of Benin (UNIBEN), Ekosodin, and the University of Benin Teaching Hospital (UBTH), consisting of four cow offals from each location. Sampling was carried out twice at two-week intervals. Heavy metal extraction was performed using the standard wet-acid digestion method, and concentrations were determined via Atomic Absorption Spectrophotometry (AAS).
Results revealed that chromium (Cr) was detected in all samples, with concentrations ranging from 0.04 to 0.19 mg/kg, while lead (Pb) was variably detected, ranging from not detected (ND) to 0.10 mg/kg. The highest Cr concentration (0.19 mg/kg) was recorded in the kidney sample from UNIBEN (UN-K), while the lowest (0.04 mg/kg) was found in the liver sample from UNIBEN (UN-L). For lead, the highest concentration was observed in the kidney sample from Ekosodin (EK-K) at 0.10 mg/kg.
When compared with the Codex Alimentarius Commission/FAO/WHO permissible limits for heavy metals in edible offals; Pb: 0.50 mg/kg, Cr: 0.05 mg/kg some of the measured Cr values, particularly in the second sampling set, exceeded the recommended safety threshold, such as 0.19 mg/kg in UN-K and 0.16 mg/kg in EK-S. These findings indicate potential contamination and raise concerns about food safety and public health, particularly among populations with high offal consumption.
These results underscore the importance of regular monitoring, improved waste and feed management, and regulatory oversight of abattoir practices to limit environmental and food-chain exposure to toxic metals.

Kola (Cola nitida) leaves are widely known for their ethnobotanical uses, yet their by- products remain underexplored as sources of bioactive compounds for environmental applications. Fermentation of plant-derived substrates often enhances their physicochemical profile, making them useful in biostimulation processes that support microbial activity for pollutant degradation. Against this background, this study investigated Cola nitida whey, focusing on its extraction, fermentation behavior, and nutrient composition, with the aim of assessing its potential application as a bioremediant. Fresh kola leaves were processed through washing, grinding, boiling, and filtration to obtain whey, which was digested with nitric acid and subjected to physicochemical analysis. Parameters evaluated included pH, electrical conductivity (EC), moisture content, total organic matter (TOM), total organic carbon (TOC), nitrate, phosphate, nitrogen, phosphorus, and potassium. Results showed dynamic changes across the five- week fermentation period. pH decreased initially from 5.29 in Week 1 to 5.18 in Week 3 before rising to 6.01 in Week 5, while EC steadily increased from 1595.50 to 2129.50 µS/cm, reflecting ionic release. Moisture content rose from 92.08% to 94.09%, whereas TOM and TOC increased overall, with TOM ranging from 54.06 to 106.55% and TOC from 31.36 to 61.80%. Nutrient levels indicated progressive mineralization: nitrate rose from 174.16 to 1152.36 mg/kg, phosphate from 411.67 to 971.81 mg/kg, nitrogen from 39.56 to 261.06 mg/kg, and phosphorus from 122.75 to 295.46 mg/kg. Potassium fluctuated but stabilized at 2.55 mg/kg by Week 5. These findings suggest that kola-leaf whey develops enriched organic and mineral content during fermentation, creating a nutrient-rich medium favorable for microbial proliferation. The shift toward near-neutral pH at later stages further supports microbial activity, while the elevated nitrate and phosphate levels highlight its suitability as a low-cost, plant-derived stimulant for bioremediation, although regulated application is recommended to minimize eutrophication risks.

This study explores how Bisphenol A (BPA) and different phthalates leach from unused plastic bottles when kept at a steady temperature of 40 °C in deionized water. The use of deionized water which is free from salts, ions, and organic matter, provided a clean, neutral environment that allowed a clear view of how these chemicals naturally migrate from plastics into water. Over a 96-hour period, BPA concentrations were measured using Gas Chromatography–Mass Spectrometry (GC–MS), with recorded values of 2.92, 2.40, 2.42, 2.74, and 2.96 µg/L at 0, 24, 48, 72, and 96 hours, respectively. The initially high BPA value was likely due to surface residues being quickly released into the water, while the slight drops at 24 and 48 hours suggest a brief stabilization or re-adsorption on the bottle surface. The subsequent rise at 72 and 96 hours indicates that BPA continued to diffuse from inside the plastic into the surrounding water which is a process encouraged by the constant heat. Phthalates such as diethyl phthalate (DEP) and dibutyl phthalate (DBP) showed similar patterns, with their concentrations gradually increasing over time, confirming that additive migration is a slow but continuous process. Although the highest BPA concentration measured (2.96 µg/L) is far below the U.S. FDA’s safety threshold of 5mg/kg body weight per day, it is well above the extremely strict European Food Safety Authority (EFSA, 2023) limit of 0.2 ng/kg body weight per day. This finding suggests that even new, unused plastics can release trace amounts of potentially harmful chemicals when exposed to warm or storage conditions for extended periods. Overall, the study emphasizes the importance of monitoring plastic safety and highlights how everyday temperature exposure can influence the release of chemical additives into water, with potential implications for both health and the environment

Ocimum gratissimum (Scent leaves) stem barks, a widely used medicinal herb, was investigated for its phytochemical composition, elemental analysis, vitamin profile, antioxidant activities, and anti-inflammatory activities. The stem bark of the plant was
successfully extracted with ethyl acetate using maceration techniques. The phytochemical examination, elemental analysis, vitamin profile, antioxidant activities and antiinflammatory activities extract of Ocimum gratissimum were determined using established method. Phytochemical screening of the water extract of the stem bark revealed the presence of alkaloids, flavonoids, saponins, glycosides, phenolic compounds, terpenoid, eugenols, protein and reducing sugar, indicating the plant’s rich bioactive profile. Elemental analysis demonstrated significant levels of essential minerals, including calcium (21.70 mg/kg), sodium (14.20 mg/kg), potassium (13.60 mg/kg), magnessium (4.68 mg/kg), and trace elements vital for human health with calcium being the most abundant. Calcium plays a vital role in the body by strengthening bones and teeth. Vitamin profiling showed
appreciable concentrations of both water-soluble vitamins (B and C) and fat-soluble vitamins (A, D, E). The concentration of vitamin B which includes B1 (0.27 mg/L), B2 (0.27 mg/L), B3 (0.60 mg/L), B6 (1.30 mg/L), and B12 (31.06 mg/L) were present in
moderate amounts except vitamin B12, which showed a slightly higher concentration. The other vitamins (A (77.84 mg/L), C (91.62 mg/L), D (66.33 mg/L), and E (104.48 mg/L)) were found in high concentrations, with vitamin E exhibiting the highest level, highlighting its nutritional relevance. The antioxidant potential were examined using FRAP (Ferric reducing antioxidant power) and Superoxide assays. In the FRAP assay, the extract shows increasing antioxidant power with %inhibition ranging from 36.08% to 66.60% at concentration of 40-160 mg/ml confirming its electron-donating capacity. In the superoxide radical scavenging assay, percentage scavenging ranged from 25.23% to 74.00% at concentration of 40-160 mg/ml, indicating concentration-dependent activity, while in anti-inflammatory studies, the extract effectively inhibited heat-induced haemolysis, with percentage inhibition increasing from 47.78% to 74.24% (40–80 mg/mL), and albumin denaturation, ranging from 55.40% to 64.40% at similar concentrations. These results indicate potent membrane stabilization and protein protection abilities of O. gratissimum stem bark extract. The findings demonstrate that O. gratissimum stem bark is rich in bioactive compounds, essential minerals, and antioxidant vitamins, which synergistically confer strong antioxidant and anti-inflammatory properties. The significant superoxide scavenging and ferric reducing power, along with inhibition of haemolysis and protein denaturation, validate its traditional use in treating oxidative stress-related disorders and inflammation. Thus, O. gratissimum may serve as a promising source of naturaltherapeutic agents for pharmaceutical and nutraceutical applications.

This study analyzed the concentrations of hydroquinone in various skin-lightening creams obtained from Ring Road, Benin City, Edo State, Nigeria. Ten cream samples were purchased locally, and hydroquinone levels were determined using UV spectrophotometry at a wavelength of 302 nm. A seven-point calibration curve was prepared to quantify the hydroquinone content in each sample. The results showed that hydroquinone concentrations ranged from 0.0030% to 0.0466%, with Caroline cream containing the highest concentration (0.0466%), while Cussons Baby cream had the lowest (0.0030%). When compared with regulatory standards set by NAFDAC, FDA, and EMA, all detected hydroquinone concentrations were found to be below the permissible limit of 2%. However, the presence of hydroquinone in these products, even at low levels, raises concerns about potential long-term exposure risks, especially for individuals who frequently use multiple skin-lightening products. To mitigate these risks, this study recommends stricter regulatory enforcement, clearer product labeling, standardized formulations, and increased public awareness regarding the effects of hydroquinone. Further research should focus on evaluating cumulative exposure risks and identifying safer alternatives for skin-lightening formulations.

This study was design to investigate the adsorption capacity of ascorbic acidonorgano-bentonite clay by studying the adsorption capacity of organo-bentoniteclay. Kinetic parameters such as time and p H from the result obtained, amount adsorbed with time increase with increase with time until equilibrium was attained, while for p H increase in p H leads to increase in amount adsorbed while equilibriumwas attained at p H 8 to 10. From the result obtained it will be seen that adsorption capacity variedwithdifferent parameter