Browsing by Author "Elbalkiny H.T."

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Chemometrics for resolving spectral data of cephalosporines and tracing their residue in waste water samples
(Elsevier B.V., 2019) Yehia A.M.; Elbalkiny H.T.; Riad S.M.; Elsaharty Y.S.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini 13 Street; Cairo; 11562; Egypt; Chemistry Department; School of Pharmacy and Pharmaceutical Industries; Badr University in Cairo; Badr City; Cairo 11829; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th of October City; 11787; Egypt
Chemometrics approaches have been used in this work to trace cephalosporins in aquatic system. Principal component regression (PCR), partial least squares (PLS), multivariate curve resolution-alternating least squares (MCR-ALS), and artificial neural networks (ANN) were compared to resolve the severally overlapped spectrum of three selected cephalosporins; cefprozil, cefradine and cefadroxil. The analytical performance of chemometric methods was compared in terms of errors. Artificial neural networks provide good recoveries with lowest error. Satisfactory results were obtained for the proposed chemometric methods whereas ANN showed better analytical performance. The qualitative meaning in MCR-ALS transformation provided very well correlations between the pure and estimated spectra of the three components. This multivariate processing of spectrophotometric data could successfully detect the studied antibiotics in waste water samples and compared favorably to alternative costly chromatographic methods. � 2019
Derivative constant wavelength synchronous fluorescence spectrometry for the simultaneous detection of cefadrine and cefadroxil in water samples
(Elsevier B.V., 2020) Elbalkiny H.T.; Yehia A.M.; Riad S.M.; Elsaharty Y.S.; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini 13 Street; Cairo; 11562; Egypt; Chemistry Department; School of Pharmacy and Pharmaceutical Industries; Badr University in Cairo; Badr City; Cairo 11829; Egypt
A sensitive accurate spectrofluorimetric technique was developed to detect cefadroxil and cefradine traces in water samples simultaneously, by applying a procedure based on the formation of hydrolysis products corresponding to these compounds by sodium hydroxide (1 N NaOH) treatment. The conventional and the synchronous fluorescence spectra of these hydrolyzed products were totally overlapped making resolving of this mixture impossible. The second-derivative constant-wavelength synchronous fluorescence spectra allowed their detection simultaneously in a single scan after experimental conditions optimization, which was measured at 390 nm and 379 nm for cefadroxil and cefradine, respectively at ?? = 30.0. The calibration curves between derivative synchronous fluorescence intensity and drugs concentration showed suitable linear correlation in the range of 0.1 to 5 ?g.mL? 1 for cefadroxil and 0.5�10 ?g.mL? 1 for cefradine. The proposed fluorimetric method is superior in being simple, environmental friendly and cost effective in comparison to the previously published reported methods. � 2019 Elsevier B.V.
Determination of fluoroquinolone antibiotics in industrial wastewater by high-pressure liquid chromatography and thin-layer chromatography-densitometric methods
(Akademiai Kiado Rt., 2014) Khattab F.I.; Salem H.; Riad S.M.; Elbalkiny H.T.; Cairo University; Analytical Chemistry Department; Faculty of Pharmacy; Kasr-El Aini Street; 11562 Cairo; Egypt; October University for Modern Sciences and Arts (MSA); Analytical Chemistry Department; Faculty of Pharmacy; 11787 6th October City; Egypt
Two methods were described for the simultaneous determination of ciprofloxacin HCl (CIP) and moxifloxacin HCl (MOX) in their binary mixture present in industrial wastewater. A solid-phase extraction procedure (SPE) based on retention on HLB OASIS cartridges and elution with a mixture of methanol-water in acidic medium was preformed, and then both fluoroquinolones were separated using two chromatographic methods. The first method was based on high-performance liquid chromatographic separation of the two drugs on reversed-phase Zorbax C18 column. The mobile phase consisted of monobasic potassium phosphate (50 mM, pH 2.5, adjusted with phosphoric acid) and acetonitrile (80:20, v/v). Flow rate was 1 mL min-1. Quantitation was achieved with ultraviolet (UV) detection at 278 nm. Linearity was found to be over the concentration range of 1-50 ?g mL-1 for both CIP and MOX. The second method was based on the thin-layer chromatographic (TLC) separation of the two drugs followed by densitometric measurements of their bands at 278 nm. The separation was carried out on silica gel 60 F254 plates, using methanol, ammonia, and methylene chloride (55:35:20, v/v) as a developing system. The linearity was found to be in the range of 0.25-2.5 ?g band -1 for both CIP and MOX. Both methods were optimized and validated as per International Conference on Harmonization (ICH) guidelines. Separation was developed on spiked water samples and checked on process wastewaters of industrial origin after SPE sample pretreatment.
Ion-Selective membrane sensors for the determination of ciprofloxacin hydrochloride in water and pharmaceutical formulation
(Center of Excellence in Electrochemistry, Univ. of Tehran, 2014) Riad S.M.; Khattab F.I.; Salem H.; Elbalkiny H.T.; Analytical Chemistry Department; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt
The construction and electrochemical response characteristics of six Ciprofloxacin-selective electrodes were investigated using precipitation based technique with sodium tetraphenyl borate (TPB), phosphomolybdate (PMA) and phosphotungstate (PTA); respectively upon using polyvinyl chloride (PVC) matrix and dibutyl phthalate (DBP) as a plasticizer. The resultant sensors have different forms, either as membrane electrodes (sensors 1, 3 and 5) or as coated wire electrodes (sensors 2, 4 and 6). Linear responses of CIP within the concentration ranges of 10?6 to 10?2 mol/L for sensors 1, 2 and 5 while for sensors 3 and 4, the linear responses were within the concentration ranges of 10?5 to 10?2 mol/L and for sensor 6 it shows linear responses within the concentration ranges of 10?7 to 10?2 mol/L. Nernstian slopes of 51.7, 50.7, 58.3, 57.7, 44 and 41.8 mV/decade were observed over the pH range of (5�9) for sensors 1, 2, 5 and 6 and over range of (5-7) for sensor 3 and 4 respectively. The selectivity coefficients of the developed sensors indicated excellent selectivity for CIP. The proposed sensors displayed useful analytical characteristics for the determination of CIP in water samples and pharmaceutical preparation. 2014 by CEE.
Monitoring and optimization of diclofenac removal by adsorption technique using in-line potentiometric analyzer
(Elsevier Inc., 2019) Yehia A.M.; Elbalkiny H.T.; Riad S.M.; Elsaharty Y.S.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini 13 Street; Cairo; 11562; Egypt; Chemistry Department; School of Pharmacy and Pharmaceutical Industries; Badr University in Cairo; Badr City; Cairo 11829; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt
Diclofenac (DICLO) is one of the most prescribed non-steroidal anti-inflammatory drugs worldwide. The presence of DICLO residues in aquatic environment either from industrial or hospital wastewater has harmful effects on many organisms. In this contribution, the adsorption of DICLO on granulated active carbon and mesoporous silica nanoparticles was optimized in order to remove those residues from water. The tracking of DICLO was done using in-line potentiometric ion-selective electrodes (ISE) through the whole experiments. The constructed electrode allows tracking of DICLO residues in real time. A central composite design was applied, inspecting the pH, initial concentration, adsorbent loading concentration and adsorbent type effects on the adsorption process, the results showed that the pH effect was most significant; pH 5 gave best results. The adsorption kinetics of these adsorbents have been investigated and the results indicated that the adsorption process followed the pseudo-second-order kinetic model. The adsorption isotherm data were analyzed by both Langmuir and Freundlich models and later provides better fit of the experimental data. The removal efficiency was about ~89% upon applying the optimum set of experimental conditions in time < 60 min. In-line monitoring is considered a green protocol, that should be carried out also at the pharmaceutical industry scale due to the high selectivity, lack of harmful waste generation and minimal solvent use. � 2019 Elsevier B.V.
Potentiometric diclofenac detection in wastewater using functionalized nanoparticles
(Elsevier Inc., 2019) Elbalkiny H.T.; Yehia A.M.; Riad S.M.; Elsaharty Y.S.; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini 13 Street; Cairo; 11562; Egypt; Chemistry Department; School of Pharmacy and Pharmaceutical Industries; Badr University in Cairo; Badr City; Cairo; 11829; Egypt
Ion selective electrodes for diclofenac monitoring in both pharmaceutical wastewater and dosage form were described; that are considered environmental friendly analytical method. The sensors development depended on comparative performance evaluation of membranes that were based on functionalized magnetite nanoparticles with the classical sensors; this approach provided that nanoparticles in the inner solution of sensor membrane were highly dispersed and coated with ionophore to enhance a complete ion-pairing interaction between the ionophore and the analyte. The optimum membrane was that containing ??cyclodextrin coupled with magnetite ferric oxide as inner filling solution, dibutylphthalate as plasticizer and crystal violet as ion exchanger in poly (vinylchloride) matrix. This sensor (CV-Fe-?-CD) exhibited high sensitivity, Nernstian slope of the calibration curve, as well as fast, stable response and good selectivity. The sensor exhibits a Nernstian slope of ?58.7 � 1 mV/decade over the concentration range 1.0 � 10?7 to 1.0 � 10?2 M of Diclofenac with a minimal limit of detection of 1.1 � 10?7 M. The electrode showed a good potentiometric selectivity for diclofenac with respect to a number of interfering ions and organic species. The membrane sensor was successfully applied for the determination of diclofenac in wastewater samples and dosage form without sample pretreatment steps prior to its analysis. � 2018 Elsevier B.V.
Removal and tracing of cephalosporins in industrial wastewater by SPE-HPLC: optimization of adsorption kinetics on mesoporous silica nanoparticles
(Springer, 2019) Elbalkiny H.T.; Yehia A.M.; Riad S.M.; Elsaharty Y.S.; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th of October City; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini 13 Street; Cairo; 11562; Egypt; Chemistry Department; School of Pharmacy and pharmaceutical industries; Badr University in Cairo; Badr City; Cairo 11829; Egypt
Cephalosporins are ?-lactam antibiotics which are considered the most widely used for humans and animals in many countries. Solid phase extraction was applied using Oasis HLB cartridges for tracing three cephalosporins (cefadroxil, cefprozil, and cefradine) in industrial wastewater samples. Sample extraction was followed by chromatographic analysis. The developed high-performance liquid chromatographic method was used for the determination of these selected cephalosporins. Separation was achieved on a Hypersil C18 column with an isocratic elution of acidified water (pH 2.5) to methanol to acetonitrile (82:12:6 per volume) at a flow rate of 1.5 mL min?1 and UV detection at 254 nm. Moreover, the proposed extraction and analysis procedures were applied to study the ability of mesoporous silica nanoparticles to remove cephalosporin residues from water by adsorption technique. A factorial design was applied to investigate the effect of pH, initial cephalosporins concentration, and adsorbent concentration on the adsorption process using removal percentage as a response. The prediction model fit well to experimental data based on statistical analysis. Adsorption kinetics and isotherm have been also studied, and the experimental results indicated that the adsorption process followed the pseudo-second-order kinetic model and Freundlich isotherm. � 2019, The Author(s).
Validated univariate and multivariate spectrophotometric methods for the determination of pharmaceuticals mixture in complex wastewater
(Blackwell Publishing Ltd, 2015) Riad S.M.; Salem H.; Elbalkiny H.T.; Khattab F.I.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Deraya University; Menia; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); October City; 11787 6th; Egypt
Five, accurate, precise, and sensitive univariate and multivariate spectrophotometric methods were developed for the simultaneous determination of a ternary mixture containing Trimethoprim (TMP), Sulphamethoxazole (SMZ) and Oxytetracycline (OTC) in waste water samples collected from different cites either production wastewater or livestock wastewater after their solid phase extraction using OASIS HLB cartridges. In univariate methods OTC was determined at its ?max 355.7 nm (0D), while (TMP) and (SMZ) were determined by three different univariate methods. Method (A) is based on successive spectrophotometric resolution technique (SSRT). The technique starts with the ratio subtraction method followed by ratio difference method for determination of TMP and SMZ. Method (B) is successive derivative ratio technique (SDR). Method (C) is mean centering of the ratio spectra (MCR). The developed multivariate methods are principle component regression (PCR) and partial least squares (PLS). The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures containing different ratios of the three drugs. The obtained results are statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at p = 0.05. � 2015 Elsevier B.V. All rights reserved.