Showing 3 results for Roi
Volume 9, Issue 2 (6-2019)
Abstract
Introduction: Along with the extensive production and use of various pesticides for controlling pests and enhancing the production of agricultural crops, there is a growing concern about the adverse effects of these toxic materials on human health. Therefore, the development of sensitive, selective, and accurate methods for continuous assessment of pesticides concentration in occupational and environmental fields and comparing them with national and international standards is of great importance. This study was aimed at synthesis and application of molecularly imprinted polymer as a selective sorbent for residue determination of two pyrethroid isomers in biological samples.
Material and Methods: The MIP particles were prepared by a non-covalent approach using permethrin as a template, chloroform as progen solvent, methacrylic acid as functional monomer and ethyleneglycol dimethacrylate as cross-linker, at 55 °C for 18 hours in an oil bath. Field emission scanning electron microscopy was used to investigate the morphology and size of polymer particles. Afterward, the critical parameters, which could affect the recognition properties of synthesized MIP, were investigated and optimized under the selected operational ranges for the highest adsorption and recycling yield in solid-phase extraction of permethrin in biological samples
Results: using precipitation polymerization technique, uniform and spherical particles with the nano-ranged diameter (less than 21.2 nanometers) were obtained. Under the optimized condition, the designed molecularly imprinted solid-phase extraction (MISPE) technique exhibited great potential for the extraction of pesticide isomers in the real sample. More than 93 % of the recovery obtained from spiked urine samples. The linear calibration curve was obtained from 20-120 μg.L-1 (R2=0.99) and the detection limit was less than 6 ppb for both isomers. The presence of interferences had no effect on the selectivity of the method up to 100-fold.
Conclusion: employing the molecular imprinted solid-phase extraction method along with the high-performance liquid chromatography technique resulted in a selective and sensitive approach, suitable for quantitative monitoring of the desired pesticide in complex biological samples.
Omid Reza Heravizadeh, Monireh Khadem, Ramin Nabizadeh, Seyed Jamaleddin Shahtaheri,
Volume 9, Issue 3 (9-2019)
Abstract
Introduction: Along with the extensive production and use of various pesticides for controlling pests and enhancing the production of agricultural crops, there is a growing concern about the adverse effects of these toxic materials on human health. Therefore, the development of sensitive, selective, and accurate methods for continuous assessment of pesticides concentration in occupational and environmental fields and comparing them with national and international standards is of great importance. This study was aimed at synthesis and application of molecularly imprinted polymer as a selective sorbent for residue determination of two pyrethroid isomers in biological samples.
Material and Methods: The MIP particles were prepared by a non-covalent approach using permethrin as a template, chloroform as progen solvent, methacrylic acid as functional monomer and ethyleneglycol dimethacrylate as cross-linker, at 55 °C for 18 hours in an oil bath. Field emission scanning electron microscopy was used to investigate the morphology and size of polymer particles. Afterward, the critical parameters, which could affect the recognition properties of synthesized MIP, were investigated and optimized under the selected operational ranges for the highest adsorption and recycling yield in solid-phase extraction of permethrin in biological samples
Results: using precipitation polymerization technique, uniform and spherical particles with the nano-ranged diameter (less than 21.2 nanometers) were obtained. Under the optimized condition, the designed molecularly imprinted solid-phase extraction (MISPE) technique exhibited great potential for the extraction of pesticide isomers in the real sample. More than 93 % of the recovery obtained from spiked urine samples. The linear calibration curve was obtained from 20-120 μg.L-1 (R2=0.99) and the detection limit was less than 6 ppb for both isomers. The presence of interferences had no effect on the selectivity of the method up to 100-fold.
Conclusion: employing the molecular imprinted solid-phase extraction method along with the high-performance liquid chromatography technique resulted in a selective and sensitive approach, suitable for quantitative monitoring of the desired pesticide in complex biological samples.
Mahboobeh Kefayati, Mahnaz Mirza Ebrahim Tehrani, Omid Saber Fard,
Volume 10, Issue 4 (11-2020)
Abstract
Introduction: Even with the rising number of diseases and their severity as well as occupational-environmental accidents occurring within organizations, most managers do not still care about the profitability of implementing the health, safety, and environment (HSE) management system requirements.
Material and Methods: Accordingly, the integration of the HSE costs calculated through engineering-economics relations was investigated to evaluate the given profitability using a different approach. For this purpose, costs of diseases and occupational-environmental accidents were computed (n=2207), and then lack of their spending was considered as system income. By determining the correlation and calculating the P-value as well as the associated costs, the regression model was subsequently fitted. Investment in the HSE management system was further examined, and return on investment (ROI) and net present value (NPV) were calculated. Afterwards, the relationship between ROI and disease recurrence rates together with occupational-environmental accidents was explored.
Results: health costs with a P-value=0.03 had a significant effect on disease recurrence rates, so that the incidence rate was equal to 1.432 e-15 as it increased by one unit. The costs of accidents with a P-value=0.048 also had a substantial impact on the occurrence of occupational accidents and a growth by one unit, wherein the accident recurrence rates were 9.183 e. However, no significant association was found between environmental accidents and disease incidence rates.
Conclusion: The results implied that investment in HSE management systems is not just in accordance with implementing profitability requirements, but it should be targeted and based on priorities, influenced by the results of examining root causes of diseases and accidents as well as assessing risks facing organizations.
