Papers by Aderonke Oyeyiola
Enhancing Composting Efficiency and Nutrient Retention through Zeolite Amendment: Implications for Sustainable Soil Management and Plant Growth
ACS sustainable resource management, Jun 22, 2024
Analysis of Antibiotics in Poultry Wastewater and Droppings Using Solid Phase Extraction and High Performance Liquid Chromatography
Journal Of Chemical Society Of Nigeria, 2016
A method was developed for the extraction, preconcentration and analysis of two antibiotics Amoxi... more A method was developed for the extraction, preconcentration and analysis of two antibiotics Amoxicillin (AMOX) and Oxytetracycline (OXY)) in poultry waste water and droppings. The method was based on solid phase extraction (SPE) and high performance liquid chromatography with ultraviolet detection (HPLC-UV). Optimization of the chromatographic conditions and the conditioning of the SPE sorbents were carried out to obtain the optimal condition for the analysis. Three eluting solvents were tested to establish the optimum conditions for the SPE procedure and pH values of samples were varied prior to HPLC analysis. Methanol gave the best percentage recoveries of 67.61% and 30.98%, followed by acetone with recoveries of 66.32% and 24.31% while acetonitrile had the poorest percentage recoveries of 64.23% and 19.05% for Amoxicillin and Oxytetracycline respectively. In the analysis of poultry waste water and droppings, the matrix components in the samples reduced the extraction efficiency leading to a decrease in the percentage recoveries of samples. The decrease in percentage recoveries obtained for the spiked poultry waste water samples followed the same trend as the standard with methanol giving the best percentage recoveries of 60.27% and 23.04%, followed by acetone with recoveries of 45.37% and 21.65% while acetonitrile gave the poorest percentage recoveries of 29.12% and 16.21% for Amoxicillin and Oxytetracycline respectively. The non-spiked poultry wastewater at pH 2.5 had the highest concentration of 19.00 ppm for the AMOX, while at pH 7.0, the lowest concentration of 10.04 ppm was observed, while for the OXY, the only detectable concentration was at pH 9.0, with a value of 6.16ppm. Keywords : Amoxicillin, antibiotics, HPLC, Oxytetracycline, poultry, SPE, wastewater
Remediation of Metal Polluted Sediments Using A Chelating Agent: Fractionation Pattern of Metals Before and After Remediation
Journal Of Chemical Society Of Nigeria, Jun 10, 2007
Spatiotemporal profiling of chemicals of emerging concern in a megacity: a case study of Lagos, Nigeria
Environmental science, 2022
This is the first study reporting the use of pharmaceutical and illicit drugs by profiling wastew... more This is the first study reporting the use of pharmaceutical and illicit drugs by profiling wastewater in Lagos, Nigeria.
Speciation of Heavy Metals in Sediments of a Polluted Tropical Stream Using the BCR Sequential Extraction Technique
Development of a Faster Technique for the Speciation of Potentially Toxic Metals in soil
Analytical Methods, 2020
h i g h l i g h t s g r a p h i c a l a b s t r a c t First method developed for micropollutants ... more h i g h l i g h t s g r a p h i c a l a b s t r a c t First method developed for micropollutants in Phragmites australis. Multi-residue determination of 81 micropollutants. Method quantitation limits were <5 ng g À1 dry weight. 17 micropollutants (including metabolites) found up to 200 ng g À1 .
Spatiotemporal profiling of chemicals of emerging concern in a megacity: a case study of Lagos, Nigeria
Environmental Science: Water Research & Technology
This is the first study reporting the use of pharmaceutical and illicit drugs by profiling wastew... more This is the first study reporting the use of pharmaceutical and illicit drugs by profiling wastewater in Lagos, Nigeria.
Journal of Soil Science and Environmental Management, Aug 31, 2011
In order to estimate plant available fraction of metals in three soils, three vegetable samples: ... more In order to estimate plant available fraction of metals in three soils, three vegetable samples: Amaranthus viridis, Celosea argentea and Corchorus olitorius were grown on contaminated soils. Matured plants were harvested and analyzed for their metal concentration. The soil samples were collected before and after planting, acid digested and analyzed to determine the pseudo total metal concentration, and quantification was done using flame -atomic absorption spectroscopy (FAAS). To correlate metal accumulation by these plants with potential bioavailability of metals in soils, sequential extraction (SE) using the modified BCR technique was performed on the soils. A secondary soil reference material (GLAURM) was used for quality control. The results of the reference material showed that the found values were within three standard deviations of the target values for the elements determined in the aqua regia digests and for most steps of the SE. It was observed that each metal differed considerably in uptake. Of the plants investigated, A. viridis had the highest tissue concentration of Cd, Cr, Pb and Zn from the soils with concentration of 1.4, 5.2 and 3.2 mgkg -1 of Cd, 76.5, 96 and 43.0 mgkg -1 of Cr, 49.5, 20.0 and 27.4 mgkg -1 of Pb and 78.1, 112 and 96.9 mgkg -1 of Zn in the soil from sites A, B and C respectively. Results of SE showed that Cd and Zn were mostly present in the acid exchangeable and reducible fractions, where these metals were mostly taken up. Soil-to-plant transfer factor values decreased in the order Zn > Cd > Cr > Pb.
Evaluation of various single extraction for the prediction of bioavailability for metals to three tropical plants grown on contaminated soils
Effects of roasting on the proximate composition and levels of polycyclic aromatic hydrocarbons in some roasted Nigerian delicacies
Journal of Emerging Trends in Engineering and Applied Sciences, 2012
Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic pollutants which get into foods during p... more Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic pollutants which get into foods during processing. In spite of this, only a few studies have been carried out on Nigerian delicacies. Raw and roasted food samples of corn (Zea mays), ripe plantain, unripe plantain (Musa paradisiaca) and yam (Dioscorea sagittifolia) of southwest Nigeria were evaluated for nutritional (proximate analysis and macro nutrients) and anti-nutritional qualities PAHs. The starchy food samples consist mainly of carbohydrate ranging from 35.93 - 55.52%, percentage crude fibre, protein, crude fat and ash content ranged between 0.82 - 14.21%, 3.15 - 8.27%, 1.12 - 19.56% and 1.12 - 2.59% respectively. The gross energy content of the food samples ranged from 777 - 1678 KJ/100g. The concentrations of minerals (macro nutrients) were as follows: Copper (7.05-20.60 ppm), Iron (3.15-28.3 ppm), Magnesium (1.15-4.95 ppm), Manganese (0.70-3.80 ppm) and Zinc (1.05-9.60 ppm). Higher levels of PAHs were found in the ro...
Sodium benzoate and potassium sorbate are preservatives commonly used in drinks and their concent... more Sodium benzoate and potassium sorbate are preservatives commonly used in drinks and their concentration is of importance due to their health implications. This research is aimed at determining the concentration of sodium benzoate and potassium sorbate in some drinks sold in Lagos, Nigeria using high performance liquid chromatography (HPLC) and UV-visible spectrometry. Thirty samples were collected from different super markets in Lagos State and the pH, as well as the concentration of sodium benzoate and potassium sorbate were determined. A significant difference was observed between the HPLC and the UV methods at 95% confidence limit. The concentration of sodium benzoate in the different drinks analysed, ranged from ND to 1040 mg/L and that of potassium sorbate from ND to 499 mg/L. It was observed that about 40 % of the drinks were above the limit of 150 mg/L for benzoate, while 43 % were found to contain concentrations of sorbate above the permissible limits of 250 and/or 300mg/L. The acceptable daily intake (ADI) per kg of body weight of some consumers was exceeded, and this could expose the consumers to the adverse effect of continuous consumption of these drinks.
A Bootstrap Model for Estimating the Concentration of Some Heavy Metal Pollutants of Ground Water from Soil
Journal of Mathematics …, 2010
... responses, )&#x27; .. 3 2 1 jn j j j ji x x x x X = is an n × k matrix of k auxiliary var... more ... responses, )&#x27; .. 3 2 1 jn j j j ji x x x x X = is an n × k matrix of k auxiliary variables, where j=1,2,
k, i=1,2,3,
,n. This approach is usually applied when the regression models built from data have regressors that are random; Sahinler et al (2007). Let the (k+1)×1 vector ...
Analytica chimica acta, Jan 22, 2017
In constructed wetlands micropollutants can be removed from water by phytoremediation. However, m... more In constructed wetlands micropollutants can be removed from water by phytoremediation. However, micropollutant uptake and metabolism by plants here is poorly understood due to the lack of good analytical approaches. Reported herein is the first methodology developed and validated for the multi-residue determination of 81 micropollutants (pharmaceuticals, personal care products and illicit drugs) in the emergent macrophyte Phragmites australis. The method involved extraction by microwave accelerated extraction (MAE), clean-up using off-line solid phase extraction and analysis by ultra-high-performance liquid chromatography tandem mass spectrometry. Development of the MAE method found the influence of studied variables on micropollutant recovery to be: extraction temperature > sample mass > solvent composition. Validation of the developed extraction protocol revealed method recoveries were in the range 80-120% for the majority of micropollutants. Method quantitation limits (MQLs...
Multivariate analysis of potentially toxic metals in sediments of a tropical coastal lagoon
Environmental Monitoring and Assessment, 2012
Journal of Environmental Sciences, 2014
Hygroscopicity of particles generated from photooxidation of α-pinene under different oxidation c... more Hygroscopicity of particles generated from photooxidation of α-pinene under different oxidation conditions in the presence of sulfate seed aerosols
Mobility, spatial variation and human health risk assessment of mercury in soil from an informal e-waste recycling site, Lagos, Nigeria
Environmental Monitoring and Assessment, 2021
Spatial variations and mobility of mercury (Hg) and Hg associations with other potentially toxic ... more Spatial variations and mobility of mercury (Hg) and Hg associations with other potentially toxic elements (PTEs) were studied in soil samples from Alaba, the largest e-waste recycling site in Nigeria and West Africa. Total Hg concentration was determined in surface soil samples from various locations using cold vapour atomic absorption spectrometry (CVAAS) following microwave-assisted acid extraction, while sequential extraction was used to determine operationally defined mobility. The concentrations of the PTEs arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn) metals were determined using inductively coupled plasma mass spectrometry (ICP-MS) following microwave-assisted digestion with aqua regia. Total Hg concentration ranged from < 0.07 to 624 mg/kg and was largely dependent on the nature and intensity of e-waste recycling activities carried out. Mobile forms of Hg, which may be HgO (a known component of some forms of e-waste), accounted for between 3.2 and 23% of the total Hg concentration, and were observed to decrease with increasing organic matter (OM). Non-mobile forms accounted for >74% of the total Hg content. In the main recycling area, soil concentrations of Cd, Cd, Cu, Hg, Mn, Ni, Pb and Zn were above soil guideline values (Environment Agency in Science Report, 2009; Kamunda et al., 2016). Strong associations were observed between Hg and other PTEs (except for Fe and Zn) with the correlational coefficient ranging from 0.731 with Cr to 0.990 with As in April, but these correlations decreased in June except for Fe. Hazard quotient values > 1 at two locations suggest that Hg may pose health threats to people working at the e-waste recycling site. It is therefore recommended that workers should be investigated for symptoms of Hg exposure.
Chemical exposure to children, especially from toys is an engineering concern. The concentration ... more Chemical exposure to children, especially from toys is an engineering concern. The concentration and availability of some potentially toxic metals (PTM) in children’s toys were determined in order to assess the risk posed by these metals to children. Samples of 25 toys imported from China to Nigeria were purchased. Ternary acid digestion followed by Atomic Absorption Spectrophotometry was used to determine the concentration of the PTM in the sample. Simulation of the saline and stomach acid extraction conditions were carried out to determine the concentrations of the PTM that could leach out from the toys during mouthing behaviour of children (available PTM) which involves chewing, sucking and swallowing. Total concentration of PTM in the toy ranged from 3.55 40.7, 3.21-38.2, 9.78-159, 3.55-11.2, and 36.1-106 mg/kg for Cd, Cr, Cu, and Pb respectively. Availability studies showed concentration range from 2.605.60 mg/kg for Pb, 0.53-2.03 mg/kg for Cd and 0.15-2.88 mg/kg for Ni after s...
Scientific African, 2020
This study seeks to quantify and assess the risk associated with the level of organophosphate and... more This study seeks to quantify and assess the risk associated with the level of organophosphate and carbamate pesticide residue in many foods commonly grown and consumed in Nigeria. Cereals, pulses, vegetables and fruits were sampled from two major markets in Lagos, Nigeria. The pesticide residue were extracted and analyzed for organophosphate and carbamate pesticide residues on a Gas Chromatograph (Agilent 7890A) hyphenated to a Mass Spectrometer (GC-MS). The concentration of dichlorvos in the cereals and pulses were all below the limit of quantification (LOQ) of 0.26 ng/g while the concentration in sorghum and beans was found to be 2.00 ng/g in both food crops. The concentration of mocap in vegetables and fruits varied from < 0.16 to 20 ng/g. Chlorpyrifos concentration in fruits and vegetables varied between < 0.50 and 30 ng/g. The concentration range of tokuthion and guthion were < 0.15 to 10 ng/g and 0.002 to 60 ng/g in vegetable and fruits respectively. Methiocarb and 3-hydroxylcarbofuran were present in all the vegetables and fruits at concentration of 1 to 30 ng/g and 2 to70 ng/g respectively. Of all the organophosphate pesticide residues analyzed in this study guthion had the highest concentration consistently while of the carbamates, 3-hydroxyl carbofuran had the highest mean concentration values for vegetables and fruits. Generally, vegetables had more organophosphate pesticide residue followed by cereals and fruits. Grains had the least amount of pesticides residue in this study. The largest amount of carbamate pesticide residue was also associated with vegetables followed by fruits. Cereals and pulses had the lowest amount of carbamates pesticide residue. None of the organophophate and carbamate pesticide residue detected were above the maximum residue limits (MRLs). Dietary risk assessment of organophosphate pesticide residues in selected foods did not indicate any health threat. Continuous monitoring and control of pesticide residues in food commodities should still be carried out to sustain the level of compliance.
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Papers by Aderonke Oyeyiola