The selection of the best mobile phase setup is one of the most important factors to be considere... more The selection of the best mobile phase setup is one of the most important factors to be considered prior to quantitative instrumentation of multiple pesticides. Usually, mobile phases comprises of water (A) and an organic solvent (B) are the setup used in liquid chromatography instruments for the analysis of pesticide residues in various samples. Unfortunately, most of the analyses are being carried out without optimization and selection of the best mobile phase setup to improve the sensitivity of the instrument. For that reason, the comparative analysis of the reportedly used mobile phases and some few suggested ones was carried out on the multi-pesticide mixture of 0.1 mg/kg (100 μg/kg) standard solutions and quantified with liquid chromatography–tandem mass spectrometry (LC–MS/MS) instrument. Consequently, the best mobile phases setup that resulted in the sum of average total chromatographic peak areas (ATCPAs) and average total chromatographic peak heights (ATCPH) for the total ion chromatography (TIC) scans as an index that correspond to the concentration levels was selected [0.1% formic acid in H2O (A) and 0.1% formic acid in acetonitrile (ACN) (B)]. And further optimization was successfully carried out on the selected mobile phase-A and the resulted setup [1% ACN and 0.1% formic acid in Milli-Q-water (mobile phase A) coupled with 0.1% formic acid in ACN (mobile phase-B)] improved the instrumental sensitivity on the targeted analytes. Thus, this justify the potential benefits of optimizing setup of the mobile phases prior to LC–MS/MS instrumentation of multi-pesticide analytes.
Aflatoxins - Occurrence, Detection and Novel Detoxification Strategies [Working Title]
Mycotoxins are secondary metabolites present in foods which can cause adverse effects on humans a... more Mycotoxins are secondary metabolites present in foods which can cause adverse effects on humans and animals. Therefore, developing a simple, effective, sensitive and validated analytical method to monitor mycotoxins is essential. Sample preparation is an important step in the analysis of mycotoxins and other contaminants from complex food matrices. Food industries in developed and developing countries have faced serious challenges with contamination of mycotoxins especially aflatoxin in food and feed products. Thus, corn and cereal-based foods are mostly affected right from pre and postharvest periods. Owing to the complexity and structural nature of mycotoxins in foods and feeds there is an urgent need for simple, effective and environmentally friendly methods of sample preparation for the detection and quantification of aflatoxins in food samples. The paper reviews the application of the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the analysis of aflatoxin...
Journal of New Materials for Electrochemical Systems, 2017
The corrosion of lead in methanesulfonic acid solution in the presence of a MnO2 air cathode in a... more The corrosion of lead in methanesulfonic acid solution in the presence of a MnO2 air cathode in a primary lead-air cell is in-vestigated. The highest power density of the lead-air cell is 2.8 mW cm-2. X-ray photoelectron spectroscopy and powder X-ray diffraction results demonstrate the formation of lead (II) oxide and lead (IV) dioxide on the air cathode after continuous discharge. Field emission scanning electron microscopy image shows that the surface coverage of lead (II) oxide and lead (IV) dioxide on the air cathode is only partial and will allow oxygen reduction.
This paper reviews the application of various modes of solid-phase microextraction (SPME) for the... more This paper reviews the application of various modes of solid-phase microextraction (SPME) for the analysis of pesticide residues in fruits and vegetables. SPME is a simple extraction technique that eliminates the use of solvent, and it is applied for the analysis of both volatile and nonvolatile pesticides. SPME has been successfully coupled to both GC and LC. The coupling with GC has been straightforward and requires little modification of existing equipment, but interfacing with LC has proved challenging. The external standard calibration technique is widely used for quantification, while standard addition and internal or surrogate standards are mainly used to account for matrix effects. All parameters that affect the extraction of pesticide residues from fruits and vegetables, and therefore need to be optimized, are also reviewed. Details of the characteristics of analytical procedures and new trends in fiber production using sol-gel technology and molecularly imprinted polymers ...
Weed competition has been a major challenge limiting crop yield especially in intercropping syste... more Weed competition has been a major challenge limiting crop yield especially in intercropping systems. Information on the use of chemicals for weed control in intercropping systems appears scanty. The aim of this study was to investigate the efficacy of pendimethalin (P) at 1 kg active ingredient/ha, and hand weeding (HW) on mineral contents of the harvested grains and effects of various weed control treatments in maize, cowpea, and their intercrop. Field experiments were carried out during the 2017 and 2018 rainy seasons. The field layout followed complete randomized block design with three replicates. There were eight treatments: Sole Maize/Cowpea + P, Sole Maize/Cowpea + P + 1HW at 3 weeks after sowing (WAS), Sole Maize/Cowpea + P+ 2HW at 3 and 6 weeks after sowing (WAS), Sole Maize/Cowpea weedy check, Intercrop + P, Intercrop + P + 1HW at 3WAS, Intercrop + P + 2HW at 3 and 6 WAS and Intercrop weedy check. It was observed that, P+1HW and P+2HW in both cropping systems have signific...
A method for the simultaneous determination and analysis of sorbic acid, benzoic acid, and natamy... more A method for the simultaneous determination and analysis of sorbic acid, benzoic acid, and natamycin in yogurt products, based on the use of the high-performance liquid chromatography with a UV detector (HPLC–UV) has been developed. This method excludes the employment of complex procedures, time-consuming and labor-intensive pre-treatment processes. Separation of the sorbic acid, benzoic acid, and natamycin with higher selectivity and sensitivity, and within five minutes was performed by a C8 150 mm × 4.6 mm x 3 μm column (HypersilTM BDS) at 20C. The mobile phase was a mixture of trifluoroacetic acid 0.1 % in water containing 100 mM sodium acetate, trifluoroacetic acid 0.1 % in acetonitrile, and trifluoroacetic acid 0.1 % in tetrahydrofuran (65:25:10 (%, v/v)). Using the mobile phase as an extraction mixture gave recoveries in the range of 83.0-110.2% at spike levels of 2.5–80.0 μg/kg with relative standard deviations (RSDs) lower than 10%. The intra-day precision and inter-day prec...
The selection of the best mobile phase setup is one of the most important factors to be considere... more The selection of the best mobile phase setup is one of the most important factors to be considered prior to quantitative instrumentation of multiple pesticides. Usually, mobile phases comprises of water (A) and an organic solvent (B) are the setup used in liquid chromatography instruments for the analysis of pesticide residues in various samples. Unfortunately, most of the analyses are being carried out without optimization and selection of the best mobile phase setup to improve the sensitivity of the instrument. For that reason, the comparative analysis of the reportedly used mobile phases and some few suggested ones was carried out on the multi-pesticide mixture of 0.1 mg/kg (100 μg/kg) standard solutions and quantified with liquid chromatography–tandem mass spectrometry (LC–MS/MS) instrument. Consequently, the best mobile phases setup that resulted in the sum of average total chromatographic peak areas (ATCPAs) and average total chromatographic peak heights (ATCPH) for the total ion chromatography (TIC) scans as an index that correspond to the concentration levels was selected [0.1% formic acid in H2O (A) and 0.1% formic acid in acetonitrile (ACN) (B)]. And further optimization was successfully carried out on the selected mobile phase-A and the resulted setup [1% ACN and 0.1% formic acid in Milli-Q-water (mobile phase A) coupled with 0.1% formic acid in ACN (mobile phase-B)] improved the instrumental sensitivity on the targeted analytes. Thus, this justify the potential benefits of optimizing setup of the mobile phases prior to LC–MS/MS instrumentation of multi-pesticide analytes.
Aflatoxins - Occurrence, Detection and Novel Detoxification Strategies [Working Title]
Mycotoxins are secondary metabolites present in foods which can cause adverse effects on humans a... more Mycotoxins are secondary metabolites present in foods which can cause adverse effects on humans and animals. Therefore, developing a simple, effective, sensitive and validated analytical method to monitor mycotoxins is essential. Sample preparation is an important step in the analysis of mycotoxins and other contaminants from complex food matrices. Food industries in developed and developing countries have faced serious challenges with contamination of mycotoxins especially aflatoxin in food and feed products. Thus, corn and cereal-based foods are mostly affected right from pre and postharvest periods. Owing to the complexity and structural nature of mycotoxins in foods and feeds there is an urgent need for simple, effective and environmentally friendly methods of sample preparation for the detection and quantification of aflatoxins in food samples. The paper reviews the application of the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the analysis of aflatoxin...
Journal of New Materials for Electrochemical Systems, 2017
The corrosion of lead in methanesulfonic acid solution in the presence of a MnO2 air cathode in a... more The corrosion of lead in methanesulfonic acid solution in the presence of a MnO2 air cathode in a primary lead-air cell is in-vestigated. The highest power density of the lead-air cell is 2.8 mW cm-2. X-ray photoelectron spectroscopy and powder X-ray diffraction results demonstrate the formation of lead (II) oxide and lead (IV) dioxide on the air cathode after continuous discharge. Field emission scanning electron microscopy image shows that the surface coverage of lead (II) oxide and lead (IV) dioxide on the air cathode is only partial and will allow oxygen reduction.
This paper reviews the application of various modes of solid-phase microextraction (SPME) for the... more This paper reviews the application of various modes of solid-phase microextraction (SPME) for the analysis of pesticide residues in fruits and vegetables. SPME is a simple extraction technique that eliminates the use of solvent, and it is applied for the analysis of both volatile and nonvolatile pesticides. SPME has been successfully coupled to both GC and LC. The coupling with GC has been straightforward and requires little modification of existing equipment, but interfacing with LC has proved challenging. The external standard calibration technique is widely used for quantification, while standard addition and internal or surrogate standards are mainly used to account for matrix effects. All parameters that affect the extraction of pesticide residues from fruits and vegetables, and therefore need to be optimized, are also reviewed. Details of the characteristics of analytical procedures and new trends in fiber production using sol-gel technology and molecularly imprinted polymers ...
Weed competition has been a major challenge limiting crop yield especially in intercropping syste... more Weed competition has been a major challenge limiting crop yield especially in intercropping systems. Information on the use of chemicals for weed control in intercropping systems appears scanty. The aim of this study was to investigate the efficacy of pendimethalin (P) at 1 kg active ingredient/ha, and hand weeding (HW) on mineral contents of the harvested grains and effects of various weed control treatments in maize, cowpea, and their intercrop. Field experiments were carried out during the 2017 and 2018 rainy seasons. The field layout followed complete randomized block design with three replicates. There were eight treatments: Sole Maize/Cowpea + P, Sole Maize/Cowpea + P + 1HW at 3 weeks after sowing (WAS), Sole Maize/Cowpea + P+ 2HW at 3 and 6 weeks after sowing (WAS), Sole Maize/Cowpea weedy check, Intercrop + P, Intercrop + P + 1HW at 3WAS, Intercrop + P + 2HW at 3 and 6 WAS and Intercrop weedy check. It was observed that, P+1HW and P+2HW in both cropping systems have signific...
A method for the simultaneous determination and analysis of sorbic acid, benzoic acid, and natamy... more A method for the simultaneous determination and analysis of sorbic acid, benzoic acid, and natamycin in yogurt products, based on the use of the high-performance liquid chromatography with a UV detector (HPLC–UV) has been developed. This method excludes the employment of complex procedures, time-consuming and labor-intensive pre-treatment processes. Separation of the sorbic acid, benzoic acid, and natamycin with higher selectivity and sensitivity, and within five minutes was performed by a C8 150 mm × 4.6 mm x 3 μm column (HypersilTM BDS) at 20C. The mobile phase was a mixture of trifluoroacetic acid 0.1 % in water containing 100 mM sodium acetate, trifluoroacetic acid 0.1 % in acetonitrile, and trifluoroacetic acid 0.1 % in tetrahydrofuran (65:25:10 (%, v/v)). Using the mobile phase as an extraction mixture gave recoveries in the range of 83.0-110.2% at spike levels of 2.5–80.0 μg/kg with relative standard deviations (RSDs) lower than 10%. The intra-day precision and inter-day prec...
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