مجلة جامعة صنعاء للعلوم التطبيقية والتكنولوجيا, Dec 20, 2023
The matrix's complexity makes measuring acrylamide in food items challenging, requiring a timecon... more The matrix's complexity makes measuring acrylamide in food items challenging, requiring a timeconsuming extraction technique and high method sensitivity. A homemade solid phase extraction (SPE) device and a gas chromatography/nitrogen phosphorus detector (GC/NPD) were used to establish a simple and inexpensive acrylamide detection method in fried fish. Optimization and validation were used to measure acrylamide concentrations in twelve fried fish samples, four of which were home-fried and eight from Sana'a, Yemen, restaurants. The validated technique has high linearity R 2 (0.995) in the 0.02-4 ppm range of acrylamide standards and good sensitivity with LOD (0.0062 ppm), substantially below the authorized level. The twelve samples had acrylamide values of 0.0583-0.4643 ppm. Due to variations in thermal treatments during frying, market-fried fish samples had greater acrylamide concentrations than home-fried fish samples. In the current study, the improved simple extraction process and GC/NPD protocol were useful for acrylamide measurement and may be employed as a prescreening tool for food sector acrylamide quantification.
ACS Sustainable Chemistry & Engineering, Jun 1, 2020
In the CO2 capture process, decreasing the energy consumption and increasing the desorption rate ... more In the CO2 capture process, decreasing the energy consumption and increasing the desorption rate of loaded MEA-CO2 during the regeneration process of monoethanol amine have been identified as major challenges that need to be addressed. To overcome these challenges, three modified heterogeneous mesoporous catalysts, CMK-3-SiO2, CMK-3-MCM-41, CMK-3-SBA-15, and SO4 2-/ZrO2 solid acid catalyst were initially synthesized and investigated to determine their catalytic effectiveness in the process of CO2 and MEA solvent regeneration with CO2 loading of 0.5±0.02 mol CO2/mol MEA at 97 o C. According to the experimental results, the CMK-3 modified catalyst significantly decreases the energy requirement for CO2 desorption. The catalytic performance of the synthesized catalysts was in the order of CMK-3-SiO2 > CMK-3-MCM-41>CMK-3-SBA-15>SZ respectively. CMK-3-SiO2 exhibited the best catalytic performance by enhancing desorption rate by 195%, and decreasing the energy requirement by 37.41% compared with the monoethanol amine as a blank run. Furthermore, the CMK-3-SiO2 catalyst exhibited the best catalytic performance compared to the literature with an excellent stability and with no unfavorable effects on the MEA-CO2 absorption activity for the regenerated amine solvent. This performance seems to be a result of the large mesoporous surface area (BET) and large number of Brϕnsted and Lewis acid sites. In addition, a reasonable reaction mechanism for the amine solvent regeneration with the CMK-3 heterogeneous catalyst is proposed.
This work was conducted to demonstrate the optimization procedures and results for a sample of pr... more This work was conducted to demonstrate the optimization procedures and results for a sample of preparation method combining Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction with cartridge solid phase extraction (c-SPE) cleanup utilized for the analysis of pesticides residues in some vegetables using gas chromatography-mass spectrometry (GC-MS). The method applied for the analysis of four pesticides of different classes; dimethoate (Organophosphorus), fenvalerate (Pyrethroid), difenoconazole (Triazole) and deltamethrin (Pyrethroid) on four types of vegetables (i.e. tomato, potato, cucumber, and carrot). The procedures simply involve the use of acetonitrile containing 1% acetic acid for the extraction, and for cleanup; a manually prepared solid-phase extraction cartridge containing primary secondary amine (PSA) and normal charcoal were used. The validated GC-MS analysis method for the pesticide residues in the selected vegetables has high linearity with R2 ranged f...
The present work reported quality assessments and stability studies of metformin hydrochloride in... more The present work reported quality assessments and stability studies of metformin hydrochloride in various brands with a label claim of 500 mg marketed in the capital Sana'a, Yemen. Physical parameters including thickness, diameter, hardness, friability, weight variation, and disintegration time were evaluated. Assay tests and dissolution rates were carried out using HPLC-UV and spectrophotometric methods respectively. All investigations were done at purchase time and after one month, three months, and six months storage conditions under an accelerated stability environment (40±2°C and 75±5% RH). The results showed that all brands of metformin hydrochloride complied with the official specification for thickness, diameter, hardness, friability, weight variation, disintegration time, dissolution, and assay tests. Assay evaluation results revealed that all tested brands have met the acceptance criteria (95%-105%) with exception of ME1 samples stored for three months whose values (94...
مجلة جامعة صنعاء للعلوم التطبيقية والتكنولوجيا, Dec 20, 2023
The presence of Hg in canned tuna flesh is a major source of customer concern. Thus, the primary ... more The presence of Hg in canned tuna flesh is a major source of customer concern. Thus, the primary goal of this investigation was to evaluate total mercury levels in Yemeni canned tuna. Thirty-one samples of seven popular locally canned tuna brands were acquired from local stores in Sana'a. A Direct Mercury Analyzer was used to determine the mercury content. The linearity of the method was tested by assessing a series of mercury standards in triplicates at concentrations ranging from 20 to 500 ppb. The correlation coefficient for this method was 0.9993. The repeatability of the procedure was measured as intra-day variation and given as the relative standard deviation, which did not exceed 4.45%. This indicated the excellent precision of the method. Mercury recoveries from spiked actual canned tuna samples were between 96.61% and 100.49%, demonstrating excellent accuracy and an acceptable procedure for mercury measurement. The limits of detection and quantitation were 1.62 ppb and 5.4 ppb, respectively. The mercury content in 31 canned tuna samples was less than the 500 ppb standard imposed by the Yemeni Organization for Standards Metrology and Quality Control (YSMO).
مجلة جامعة صنعاء للعلوم التطبيقية والتكنولوجيا, Dec 20, 2023
The matrix's complexity makes measuring acrylamide in food items challenging, requiring a timecon... more The matrix's complexity makes measuring acrylamide in food items challenging, requiring a timeconsuming extraction technique and high method sensitivity. A homemade solid phase extraction (SPE) device and a gas chromatography/nitrogen phosphorus detector (GC/NPD) were used to establish a simple and inexpensive acrylamide detection method in fried fish. Optimization and validation were used to measure acrylamide concentrations in twelve fried fish samples, four of which were home-fried and eight from Sana'a, Yemen, restaurants. The validated technique has high linearity R 2 (0.995) in the 0.02-4 ppm range of acrylamide standards and good sensitivity with LOD (0.0062 ppm), substantially below the authorized level. The twelve samples had acrylamide values of 0.0583-0.4643 ppm. Due to variations in thermal treatments during frying, market-fried fish samples had greater acrylamide concentrations than home-fried fish samples. In the current study, the improved simple extraction process and GC/NPD protocol were useful for acrylamide measurement and may be employed as a prescreening tool for food sector acrylamide quantification.
ACS Sustainable Chemistry & Engineering, Jun 1, 2020
In the CO2 capture process, decreasing the energy consumption and increasing the desorption rate ... more In the CO2 capture process, decreasing the energy consumption and increasing the desorption rate of loaded MEA-CO2 during the regeneration process of monoethanol amine have been identified as major challenges that need to be addressed. To overcome these challenges, three modified heterogeneous mesoporous catalysts, CMK-3-SiO2, CMK-3-MCM-41, CMK-3-SBA-15, and SO4 2-/ZrO2 solid acid catalyst were initially synthesized and investigated to determine their catalytic effectiveness in the process of CO2 and MEA solvent regeneration with CO2 loading of 0.5±0.02 mol CO2/mol MEA at 97 o C. According to the experimental results, the CMK-3 modified catalyst significantly decreases the energy requirement for CO2 desorption. The catalytic performance of the synthesized catalysts was in the order of CMK-3-SiO2 > CMK-3-MCM-41>CMK-3-SBA-15>SZ respectively. CMK-3-SiO2 exhibited the best catalytic performance by enhancing desorption rate by 195%, and decreasing the energy requirement by 37.41% compared with the monoethanol amine as a blank run. Furthermore, the CMK-3-SiO2 catalyst exhibited the best catalytic performance compared to the literature with an excellent stability and with no unfavorable effects on the MEA-CO2 absorption activity for the regenerated amine solvent. This performance seems to be a result of the large mesoporous surface area (BET) and large number of Brϕnsted and Lewis acid sites. In addition, a reasonable reaction mechanism for the amine solvent regeneration with the CMK-3 heterogeneous catalyst is proposed.
This work was conducted to demonstrate the optimization procedures and results for a sample of pr... more This work was conducted to demonstrate the optimization procedures and results for a sample of preparation method combining Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction with cartridge solid phase extraction (c-SPE) cleanup utilized for the analysis of pesticides residues in some vegetables using gas chromatography-mass spectrometry (GC-MS). The method applied for the analysis of four pesticides of different classes; dimethoate (Organophosphorus), fenvalerate (Pyrethroid), difenoconazole (Triazole) and deltamethrin (Pyrethroid) on four types of vegetables (i.e. tomato, potato, cucumber, and carrot). The procedures simply involve the use of acetonitrile containing 1% acetic acid for the extraction, and for cleanup; a manually prepared solid-phase extraction cartridge containing primary secondary amine (PSA) and normal charcoal were used. The validated GC-MS analysis method for the pesticide residues in the selected vegetables has high linearity with R2 ranged f...
The present work reported quality assessments and stability studies of metformin hydrochloride in... more The present work reported quality assessments and stability studies of metformin hydrochloride in various brands with a label claim of 500 mg marketed in the capital Sana'a, Yemen. Physical parameters including thickness, diameter, hardness, friability, weight variation, and disintegration time were evaluated. Assay tests and dissolution rates were carried out using HPLC-UV and spectrophotometric methods respectively. All investigations were done at purchase time and after one month, three months, and six months storage conditions under an accelerated stability environment (40±2°C and 75±5% RH). The results showed that all brands of metformin hydrochloride complied with the official specification for thickness, diameter, hardness, friability, weight variation, disintegration time, dissolution, and assay tests. Assay evaluation results revealed that all tested brands have met the acceptance criteria (95%-105%) with exception of ME1 samples stored for three months whose values (94...
مجلة جامعة صنعاء للعلوم التطبيقية والتكنولوجيا, Dec 20, 2023
The presence of Hg in canned tuna flesh is a major source of customer concern. Thus, the primary ... more The presence of Hg in canned tuna flesh is a major source of customer concern. Thus, the primary goal of this investigation was to evaluate total mercury levels in Yemeni canned tuna. Thirty-one samples of seven popular locally canned tuna brands were acquired from local stores in Sana'a. A Direct Mercury Analyzer was used to determine the mercury content. The linearity of the method was tested by assessing a series of mercury standards in triplicates at concentrations ranging from 20 to 500 ppb. The correlation coefficient for this method was 0.9993. The repeatability of the procedure was measured as intra-day variation and given as the relative standard deviation, which did not exceed 4.45%. This indicated the excellent precision of the method. Mercury recoveries from spiked actual canned tuna samples were between 96.61% and 100.49%, demonstrating excellent accuracy and an acceptable procedure for mercury measurement. The limits of detection and quantitation were 1.62 ppb and 5.4 ppb, respectively. The mercury content in 31 canned tuna samples was less than the 500 ppb standard imposed by the Yemeni Organization for Standards Metrology and Quality Control (YSMO).
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