Browsing by Author "Monir, Hany H"

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Appraisal for Edible Use of Vegetable Crops Cultivated in Egypt after 2 Treatment with Selected Insecticides and Fungicides: Insights of Dissipation 3 Rates and Pre-Harvest intervals
(J-Stage, 7/16/2021) Saleh, Sarah S; Monir, Hany H; El-Naem, Omnia A
An analytical investigation was carried out to study the dissipation rate of two commonly used pesticides, Thiamethoxam (neonicotinoid insecticide) and propamocarb hydrochloride (carbamate fungicide) applied to four vegetable crops: cucumber, zucchini, lettuce and pepper, after open- field application. Samples were harvested according to a scheduled plan followed by QuEChERS extraction, then thiamethoxam residues were analyzed using a GC-ECD method, while propamocarb HCl residues were analyzed using an HPLC-UV method. Validation parameters were attained for both methods and the kinetic profile was studied which fitted the first –order kinetics where k, t ½ and t90 were calculated. The proper pre-harvest interval (PHI) was studied for each crop to ensure that the residues levels declined to reach below the maximum residue limit (MRL) where the crop is suitable for edible use. These values were found to be different from labelled values which proves that the PHIs are greatly affected by changing weather conditions.
Implementation of quality by design approach for optimization of the green voltammetric analysis of a brain doping agent (Piracetam) using a novel molecular imprinted polymeric sensor
(Elsevier Inc, 2024-08) Medhat, Passant M; Fouad, Manal Mohamed; Mahmoud, Amr M; Ghoniem, Nermine S; Monir, Hany H
It is encouraging to note that in recent years there has been a growth of high-quality articles detailing molecular imprinted sensors for the detection of biomolecules, illicit narcotics, and explosives, paving the way for the technology's usage in forensic and medical diagnostics. Thus in this work, a molecularly imprinted polymeric sensor was fabricated, for the first time, for the sensitive and selective determination of a brain doping agent; Piracetam, using a pencil-graphite electrode. This sensor was created by the simple anodic electro-polymerization of o-phenylenediamine (o-PD) with Piracetam as the template. Then the sensor was activated by removing the template using a suitable solvent mixture. Because of Piracetam's lack of electro-activity, [Fe (CN)6]3−/4− has been used as an electrochemical probe that produces analytically relevant voltammetric signals by competing for the binding sites. Based on UV-spectrophotometric measurements, Job's approach confirmed the expected stoichiometric ratio between Piracetam and the chosen monomer. X-ray photoelectron spectroscopy and cyclic voltammetry techniques were used for the characterization of the fabricated sensors. Different factors affecting the electro-polymerization conditions as; the effect of scan rate, number of cycles, pH of electro-polymerization, and the incubation time for rebinding were studied and optimized using fractional factorial design, in which the predicted model fits well to the experimental data as proved by ANOVA results. The developed voltammetric platform was applied for the in-line quantification of Piracetam in its pure solutions, pharmaceutical dosage form, and spiked human plasma with high accuracy and selectivity without the interference of the co-formulated drug; Citicoline sodium and excipients. The proposed molecular imprinted sensor was very sensitive with a linearity range (1.00 × 10−13 − 1.00 × 10−12 M), with LOD down to 4.38 × 10−15 M. This method was statistically compared with the reported method, and no statistically significant difference was found. The proposed method was assessed for greenness quantitatively and qualitatively using the Green Analytical Procedure Index (GAPI) and Analytical GREEnness metric (AGREE) as new greenness assessment tools.