Process safety and environmental protection/Transactions of the Institution of Chemical Engineers. Part B, Process safety and environmental protection/Chemical engineering research and design/Chemical engineering research & design, 2024
The investigation focused on a methodology for concentrating and analyzing Cr(VI) in aqueous samp... more The investigation focused on a methodology for concentrating and analyzing Cr(VI) in aqueous samples. This objective was accomplished through the creation of a cellulose triacetate (CTA) matrix-based membrane optode. This optode was constructed by physically integrating a specific chromophore, 1,3benzenediamine,N,N ′-bis(2-furanylmethylene) (BDBFM), known for its selectivity towards Cr(VI), alongside the plasticizer dioctylphthalate (DOP). The effectiveness of integrating Aliquat 336, an anion exchanger, was evaluated in the process of immobilizing both BDBFM and the Cr(VI)-BDBFM complex within the optode matrix. The progressive intensification of the violet color observed on the optodes, directly correlating with the amount of loaded Cr(VI), highlights the potential of this method for colorimetric screening of Cr(VI) in aqueous samples. The developed optode was also employed for the determination of the total chromium content by converting Cr(III) to Cr(VI) via oxidation using 0.1 M hydrogen peroxide. The concentration of Cr(III) can be quantified by subtracting the amount of Cr(VI) from the total chromium content. This optode enabled the quantitative detection of Cr(VI), even at levels as low as 2.85 ng mL −1. The suggested sensor displayed a low detection limit, fast response time, cost effectiveness, ease of preparation and also remarkable selectivity regarding some anions and cations. Regeneration of the optode can be easily accomplished by employing 0.05 M HNO 3 , while demonstrating remarkable reproducibility and reversibility in its response, with a relative standard deviation (RSD) below 1.9. The suggested method was effectively utilized to measure chromium levels in a diverse range of samples, such as food, water, and environmental, and biological samples. Environmental signicance The optode developed in this study offers a straightforward and efficient method for detecting Cr(VI) ions. Its utilization of cellulose triacetate as a matrix ensures favorable optical and mechanical properties. Notably, the optode exhibits a reversible color change from yellow to violet upon exposure to Cr(VI) ions, and it can be easily regenerated using a 0.05 M HNO 3 solution with complete reversibility. Compared to previously reported optical sensors for Cr(VI) detection, the proposed optode demonstrates a signicantly faster response time. An important aspect of this study is the novel application of BDBFM in combination with the proposed optode for the determination of Cr(VI) ions. This approach has not been documented in the existing literature, making this study the rst to employ BDBFM in conjunction with the proposed optode. Furthermore, the versatility of the optode sensor extends to its successful implementation in monitoring BDBFM across various sample types, including water, food, and biological, and environmental samples. This wide range of applications showcases the potential of the optode sensor beyond its primary use in Cr(VI) determination.
Food safety has become a serious global concern because of the accumulation of potentially toxic ... more Food safety has become a serious global concern because of the accumulation of potentially toxic metals (PTMs) in crops cultivated on contaminated agricultural soils. Amongst these toxic elements, arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) receive worldwide attention because of their ability to cause deleterious health effects. Thus, an assessment of these toxic metals in the soils, irrigation waters, and the most widely consumed vegetables in Nigeria; Spinach (Amaranthushybridus), and Cabbage (Brassica oleracea) was evaluated using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentration (measured in mg kg -1 ) of the PTMs in the soils was in the sequence Cr (81.77) > Pb(19.91) > As(13.23) > Cd(3.25), exceeding the WHO recommended values in all cases. This contamination was corroborated by the pollution evaluation indices. The concentrations (measured in mg l -1 ) of the PTMs in the irrigation water followed a similar pattern i.e. Cr(1.87) > Pb(1.65) > As(0.85) > Cd(0.20). All the PTMs being studied, were found in the vegetables with Cr (5.37 and 5.88) having the highest concentration, followed by Pb (3.57 and 4.33), and As (1.09 and 1.67), while Cd (0.48 and 1.04) had the lowest concentration (all measured in mg kg -1 ) for cabbage and spinach, respectively. The concentration of the toxic metals was higher in spinach than in cabbage, which may be due to the redistribution of the greater proportion of the metals above the ground tissue, caused by the bioavailability of metals in the aqueous phase. Expectedly, the hazard index (HI),and carcinogenic risk values of spinach were higher than that of cabbage. This implies that spinach poses potentially higher health risks. Similarly, the Monte Carlo simulation results reveal that the 5th percentile, 95th percentile, and 50th percentile of the cumulative probability of cancer risks due to the consumption of these vegetables exceeds the acceptable range of 1.00E-6 and 1.00E-4. Thus, the probable risk of a cancerous effect is high, and necessary remedial actions are recommended. The soil, though it serves as a membrane for the surface of the earth, also serves as a reservoir for various potentially toxic metals (PTMs). The PTMs are usually transferred from the hydrosphere, biomass, atmosphere, and lithosphere 1-3 . These PTMs are generally generated as a result of both anthropogenic and lithogenic activities. Although PTMs generated as a result of human (anthropogenic) activities are said to be more noteworthy and
A novel optical sensor has been developed to measure selenium ions. The sensor membrane was creat... more A novel optical sensor has been developed to measure selenium ions. The sensor membrane was created by mixing xylenol orange (XO) and sodium tetraphenylborate (NaTPB) with a plasticized poly(vinyl chloride) membrane that contained o-nitrophenyl octyl ether (o-NPOE) as a plasticizer. XO was previously established for use in a colorimeter to measure selenium in water and other media. At pH 6.6, the color of the detecting membrane changed from orange to pink when in contact with Se 4+ ions. Various variables affecting the uptake efficiency were evaluated and optimized. Under optimum conditions (i.e., 30% PVC, 60% o-NPOE, and 5.0% of both XO and NaTPB for 5.0 min as the response time), the proposed sensor displayed a linear range 10-175 ng mL −1 with the detection and quantification limits of 3.0 and 10 ng mL −1 , respectively. Also, the precision (RSD%) was better than 2.2% for six replicate determinations of 100 ng mL −1 Se 4+ in various membranes. For the detection of Se 4+ , the selectivity of the sensor membrane was investigated for a number of possible interfering inorganic cations, but no appreciable interference was found. With the use of a 0.3 M HCl solution, the sensor was successfully restored, and the response that may have been reversible and reproducible exhibited an RSD% of less than 2.0%. The sensor has been successfully used to analyze Se 4+ ions in environmental and biological materials.
Water contamination from a variety of sources has made it increasingly difficult to contact clean... more Water contamination from a variety of sources has made it increasingly difficult to contact clean drinking water. The release of effluents into water bodies is a serious environmental problem. This study presents the synthesis of magnesium-doped copper oxide (Mg-CuO) nanoparticles as a promising adsorbent for the efficient removal of Congo Red dye from aqueous solutions. Mg-CuO nanoparticles were synthesized via a facile and cost-effective co-precipitation method and characterized using various techniques. The adsorption capacity of Mg-CuO nanoparticles for Congo Red dye was systematically investigated, revealing outstanding adsorption efficiency. Equilibrium adsorption data were well-fitted to the Langmuir isotherm model, suggesting monolayer adsorption behavior, while the Freundlich Isotherm model described the adsorption behavior accurately. The influence of various experimental parameters, including initial dye concentration, pH, adsorbent dosage, and contact time, on the adsorption process was studied in detail. Optimal conditions (pH=6, concentration=50ppm, contact time=120minutes) for maximal adsorption efficiency were determined. Moreover, the thermodynamic analysis specified that the adsorption of Congo Red onto Mg-CuO nanoparticles was spontaneous and endothermic. The exceptional adsorption performance of Mg-CuO nanoparticles, attributed to the synergistic effect of magnesium doping and high surface area, highlights their potential as an eco-friendly and efficient adsorbent for the removal of Congo Red dye from wastewater. This research contributes to the advancement of sustainable materials for environmental remediation and underscores the importance of exploring nanomaterials for water purification applications.
We report the preparation and cytotoxicity of two new eugenol derivatives that contain 1,3,4-oxad... more We report the preparation and cytotoxicity of two new eugenol derivatives that contain 1,3,4-oxadiazole, as novel inhibitors of thymidylate synthase; these derivatives are shown to be promising chemotherapeutic agents.
A pioneering optical sensor has been effectively developed to achieve precise and reliable detect... more A pioneering optical sensor has been effectively developed to achieve precise and reliable detection of titanium ions. The sensor employs an optode membrane composed of 2-amino-4-((4-nitrophenyl) diazenyl)pyridine-3-ol (ANPDP) and sodium tetraphenylborate (NaTPB) incorporated into a plasticized PVC matrix, with dioctyl sebacate (DOS) acting as the plasticizer. When exposed to Ti 4+ ions at pH 8.25, the color of the sensing membrane undergoes a distinctive transformation from yellow-orange to violet. Extensive investigations were carried out to assess and optimize various factors influencing the efficiency of ion uptake. Through careful experimentation, the optimum conditions were determined to be 60.0% DOS, 6.0% ANPDP, 30% PVC, and 4.0% NaTPB, with a rapid response time of 5.0 min. Within these conditions, the developed optode demonstrates an impressive linear range of 3.0-225 ng mL −1 , boasting detection (LOD) and quantification (LOQ) limits of 0.91 and 2.95 ng mL −1 , respectively. Moreover, the precision of the sensor, as indicated by the relative standard deviation (RSD%), remained consistently below 1.55% in six replicate determinations of 100 ng mL −1 Ti 4+ across diverse membranes. The selectivity of the sensor was rigorously examined for a range of cations and anions, successfully establishing the tolerance limits for interfering species. Notably, the presence of EDTA as a masking agent did not compromise the high selectivity of the sensor. Consequently, the innovative probe holds significant potential as a reliable analytical tool for quantifying titanium content in various samples, including water, geological materials, soil, plants, paints, cosmetics, and plastics.
An optical chemical sensor has been developed for the quantitative spectrophotometric analysis of... more An optical chemical sensor has been developed for the quantitative spectrophotometric analysis of copper.
Process safety and environmental protection/Transactions of the Institution of Chemical Engineers. Part B, Process safety and environmental protection/Chemical engineering research and design/Chemical engineering research & design, 2024
The investigation focused on a methodology for concentrating and analyzing Cr(VI) in aqueous samp... more The investigation focused on a methodology for concentrating and analyzing Cr(VI) in aqueous samples. This objective was accomplished through the creation of a cellulose triacetate (CTA) matrix-based membrane optode. This optode was constructed by physically integrating a specific chromophore, 1,3benzenediamine,N,N ′-bis(2-furanylmethylene) (BDBFM), known for its selectivity towards Cr(VI), alongside the plasticizer dioctylphthalate (DOP). The effectiveness of integrating Aliquat 336, an anion exchanger, was evaluated in the process of immobilizing both BDBFM and the Cr(VI)-BDBFM complex within the optode matrix. The progressive intensification of the violet color observed on the optodes, directly correlating with the amount of loaded Cr(VI), highlights the potential of this method for colorimetric screening of Cr(VI) in aqueous samples. The developed optode was also employed for the determination of the total chromium content by converting Cr(III) to Cr(VI) via oxidation using 0.1 M hydrogen peroxide. The concentration of Cr(III) can be quantified by subtracting the amount of Cr(VI) from the total chromium content. This optode enabled the quantitative detection of Cr(VI), even at levels as low as 2.85 ng mL −1. The suggested sensor displayed a low detection limit, fast response time, cost effectiveness, ease of preparation and also remarkable selectivity regarding some anions and cations. Regeneration of the optode can be easily accomplished by employing 0.05 M HNO 3 , while demonstrating remarkable reproducibility and reversibility in its response, with a relative standard deviation (RSD) below 1.9. The suggested method was effectively utilized to measure chromium levels in a diverse range of samples, such as food, water, and environmental, and biological samples. Environmental signicance The optode developed in this study offers a straightforward and efficient method for detecting Cr(VI) ions. Its utilization of cellulose triacetate as a matrix ensures favorable optical and mechanical properties. Notably, the optode exhibits a reversible color change from yellow to violet upon exposure to Cr(VI) ions, and it can be easily regenerated using a 0.05 M HNO 3 solution with complete reversibility. Compared to previously reported optical sensors for Cr(VI) detection, the proposed optode demonstrates a signicantly faster response time. An important aspect of this study is the novel application of BDBFM in combination with the proposed optode for the determination of Cr(VI) ions. This approach has not been documented in the existing literature, making this study the rst to employ BDBFM in conjunction with the proposed optode. Furthermore, the versatility of the optode sensor extends to its successful implementation in monitoring BDBFM across various sample types, including water, food, and biological, and environmental samples. This wide range of applications showcases the potential of the optode sensor beyond its primary use in Cr(VI) determination.
Food safety has become a serious global concern because of the accumulation of potentially toxic ... more Food safety has become a serious global concern because of the accumulation of potentially toxic metals (PTMs) in crops cultivated on contaminated agricultural soils. Amongst these toxic elements, arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) receive worldwide attention because of their ability to cause deleterious health effects. Thus, an assessment of these toxic metals in the soils, irrigation waters, and the most widely consumed vegetables in Nigeria; Spinach (Amaranthushybridus), and Cabbage (Brassica oleracea) was evaluated using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentration (measured in mg kg -1 ) of the PTMs in the soils was in the sequence Cr (81.77) > Pb(19.91) > As(13.23) > Cd(3.25), exceeding the WHO recommended values in all cases. This contamination was corroborated by the pollution evaluation indices. The concentrations (measured in mg l -1 ) of the PTMs in the irrigation water followed a similar pattern i.e. Cr(1.87) > Pb(1.65) > As(0.85) > Cd(0.20). All the PTMs being studied, were found in the vegetables with Cr (5.37 and 5.88) having the highest concentration, followed by Pb (3.57 and 4.33), and As (1.09 and 1.67), while Cd (0.48 and 1.04) had the lowest concentration (all measured in mg kg -1 ) for cabbage and spinach, respectively. The concentration of the toxic metals was higher in spinach than in cabbage, which may be due to the redistribution of the greater proportion of the metals above the ground tissue, caused by the bioavailability of metals in the aqueous phase. Expectedly, the hazard index (HI),and carcinogenic risk values of spinach were higher than that of cabbage. This implies that spinach poses potentially higher health risks. Similarly, the Monte Carlo simulation results reveal that the 5th percentile, 95th percentile, and 50th percentile of the cumulative probability of cancer risks due to the consumption of these vegetables exceeds the acceptable range of 1.00E-6 and 1.00E-4. Thus, the probable risk of a cancerous effect is high, and necessary remedial actions are recommended. The soil, though it serves as a membrane for the surface of the earth, also serves as a reservoir for various potentially toxic metals (PTMs). The PTMs are usually transferred from the hydrosphere, biomass, atmosphere, and lithosphere 1-3 . These PTMs are generally generated as a result of both anthropogenic and lithogenic activities. Although PTMs generated as a result of human (anthropogenic) activities are said to be more noteworthy and
A novel optical sensor has been developed to measure selenium ions. The sensor membrane was creat... more A novel optical sensor has been developed to measure selenium ions. The sensor membrane was created by mixing xylenol orange (XO) and sodium tetraphenylborate (NaTPB) with a plasticized poly(vinyl chloride) membrane that contained o-nitrophenyl octyl ether (o-NPOE) as a plasticizer. XO was previously established for use in a colorimeter to measure selenium in water and other media. At pH 6.6, the color of the detecting membrane changed from orange to pink when in contact with Se 4+ ions. Various variables affecting the uptake efficiency were evaluated and optimized. Under optimum conditions (i.e., 30% PVC, 60% o-NPOE, and 5.0% of both XO and NaTPB for 5.0 min as the response time), the proposed sensor displayed a linear range 10-175 ng mL −1 with the detection and quantification limits of 3.0 and 10 ng mL −1 , respectively. Also, the precision (RSD%) was better than 2.2% for six replicate determinations of 100 ng mL −1 Se 4+ in various membranes. For the detection of Se 4+ , the selectivity of the sensor membrane was investigated for a number of possible interfering inorganic cations, but no appreciable interference was found. With the use of a 0.3 M HCl solution, the sensor was successfully restored, and the response that may have been reversible and reproducible exhibited an RSD% of less than 2.0%. The sensor has been successfully used to analyze Se 4+ ions in environmental and biological materials.
Water contamination from a variety of sources has made it increasingly difficult to contact clean... more Water contamination from a variety of sources has made it increasingly difficult to contact clean drinking water. The release of effluents into water bodies is a serious environmental problem. This study presents the synthesis of magnesium-doped copper oxide (Mg-CuO) nanoparticles as a promising adsorbent for the efficient removal of Congo Red dye from aqueous solutions. Mg-CuO nanoparticles were synthesized via a facile and cost-effective co-precipitation method and characterized using various techniques. The adsorption capacity of Mg-CuO nanoparticles for Congo Red dye was systematically investigated, revealing outstanding adsorption efficiency. Equilibrium adsorption data were well-fitted to the Langmuir isotherm model, suggesting monolayer adsorption behavior, while the Freundlich Isotherm model described the adsorption behavior accurately. The influence of various experimental parameters, including initial dye concentration, pH, adsorbent dosage, and contact time, on the adsorption process was studied in detail. Optimal conditions (pH=6, concentration=50ppm, contact time=120minutes) for maximal adsorption efficiency were determined. Moreover, the thermodynamic analysis specified that the adsorption of Congo Red onto Mg-CuO nanoparticles was spontaneous and endothermic. The exceptional adsorption performance of Mg-CuO nanoparticles, attributed to the synergistic effect of magnesium doping and high surface area, highlights their potential as an eco-friendly and efficient adsorbent for the removal of Congo Red dye from wastewater. This research contributes to the advancement of sustainable materials for environmental remediation and underscores the importance of exploring nanomaterials for water purification applications.
We report the preparation and cytotoxicity of two new eugenol derivatives that contain 1,3,4-oxad... more We report the preparation and cytotoxicity of two new eugenol derivatives that contain 1,3,4-oxadiazole, as novel inhibitors of thymidylate synthase; these derivatives are shown to be promising chemotherapeutic agents.
A pioneering optical sensor has been effectively developed to achieve precise and reliable detect... more A pioneering optical sensor has been effectively developed to achieve precise and reliable detection of titanium ions. The sensor employs an optode membrane composed of 2-amino-4-((4-nitrophenyl) diazenyl)pyridine-3-ol (ANPDP) and sodium tetraphenylborate (NaTPB) incorporated into a plasticized PVC matrix, with dioctyl sebacate (DOS) acting as the plasticizer. When exposed to Ti 4+ ions at pH 8.25, the color of the sensing membrane undergoes a distinctive transformation from yellow-orange to violet. Extensive investigations were carried out to assess and optimize various factors influencing the efficiency of ion uptake. Through careful experimentation, the optimum conditions were determined to be 60.0% DOS, 6.0% ANPDP, 30% PVC, and 4.0% NaTPB, with a rapid response time of 5.0 min. Within these conditions, the developed optode demonstrates an impressive linear range of 3.0-225 ng mL −1 , boasting detection (LOD) and quantification (LOQ) limits of 0.91 and 2.95 ng mL −1 , respectively. Moreover, the precision of the sensor, as indicated by the relative standard deviation (RSD%), remained consistently below 1.55% in six replicate determinations of 100 ng mL −1 Ti 4+ across diverse membranes. The selectivity of the sensor was rigorously examined for a range of cations and anions, successfully establishing the tolerance limits for interfering species. Notably, the presence of EDTA as a masking agent did not compromise the high selectivity of the sensor. Consequently, the innovative probe holds significant potential as a reliable analytical tool for quantifying titanium content in various samples, including water, geological materials, soil, plants, paints, cosmetics, and plastics.
An optical chemical sensor has been developed for the quantitative spectrophotometric analysis of... more An optical chemical sensor has been developed for the quantitative spectrophotometric analysis of copper.
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