Ragaa El-Sheikh

Oxidation of Levafix CA reactive azo-dyes in industrial wastewater of textile dyeing by electro-generated Fenton's reagent

The indirect electrochemical removal of pollutants from effluents has become an attractive method in recent years. Removal (decolorization and mineralization) of Levafix Blue CA and Levafix Red CA reactive azo-dyes from aqueous media by electro-generated Fentons reagent (Fe(2+)/H(2)O(2)) using a reticulated vitreous carbon cathode and a platinum gauze anode was optimized. Progress of oxidation (decolorization and mineralization) of the investigated azo-dyes with time of electro-Fentons reaction was monitored by UV-visible absorbance measurements, Chemical oxygen demand (COD) removal and HPLC analysis. The results indicated that the electro-Fentons oxidation system is efficient for treatment of such types of reactive dyes. Oxidation of each of the investigated azo-dyes by electro-generated Fentons reagent up to complete decolorization and approximately 90-95% mineralization was achieved. Moreover, the optimized electro-Fentons oxidation was successfully applied for complete decolorization and approximately 85-90% mineralization of both azo-dyes in real industrial wastewater samples collected from textile dyeing house at El-Mahalla El-Kobra, Egypt.

Plastic membrane and coated Wire Ion Selective Electrodes for Propylhexedrine

Abstract Propylhexedrine (PX) ion selective electrode based on plasti-cized (PX)-tetraphenylboron with dioctylphthalate in poly(vinyl chloride) (PVC)-matrix. The electrode shows near Nernstian response over the concentration range 2.5×10−5 -10−1 solutions of the drug. The working pH-range of the electrode is 2.5-9.5 at 25°C. The electrode response can be considered Nernstian over the temperature range 25-60°C with isothermal temperature coefficient 0.00025 V/°C. The selectivity coefficient of the electrode is calculated towards several inorganic cations, sugars, amines, amino acids and some other pharmaceutical preparations. Also, a coated wire ion-selective electrode based on the same ion pair was found to give a Nernstian response for a concentration range of 10−4-10−2 M PXH+ solution.

Potentiometric Sensor for Phenylephrine Based on Phenylephrine-tetraphenylborate Lipophilic Salt

Phenylephrine (PE) ion-selective electrode based on incorporation of phenylephrine-tetraphenylborate lipophilic salt in plasticized PVC matrices is constructed. The electrode shows near Nernstian response over the concentration range 1.5 × 10−4-10−1M in solutions of pH 2.9–8.0 at 25°C. The electrode resists the effect of heat in the temperature range 25–55°C exhibiting an isothermal temperature coefficient of 0.0007 V/°C. The selectivity of the electrode for PE towards large number of inorganic cations, sugars and amino acids is investigated. Determination of PE in an eye-drops pharmaceutical preparation is carried out using the proposed electrode as potentiometric sensor.

Spectrophotometric Determination of Gemifloxacin Mesylate, Moxifloxacin Hydrochloride, and Enrofloxacin in Pharmaceutical Formulations Using Acid Dyes

Simple, rapid, and extractive spectrophotometric methods were developed for the determination of some fluoroquinolones antibiotics: gemifloxacin mesylate (GMF), moxifloxacin hydrochloride (MXF), and enrofloxacin (ENF) in pure forms and pharmaceutical formulations. These methods are based on the formation of ion-pair complexes between the basic drugs and acid dyes, namely, bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB), bromothymol blue (BTB), and methyl orange (MO) in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 420, 408, 416, 415, and 422 nm for BCG, BCP, BPB, BTB, and MO, respectively, for GMF; at 410, 415, 416, and 420 nm for BCP, BTB, BPB, and MO, respectively, for MXF; and at 419 and 414 nm for BCG and BTB, respectively, in case of ENF. The analytical parameters and their effects are investigated. Beers law was obeyed in the ranges 1.0–30, 1.0–20, and 2.0–24 μg mL−1 for GMF, MXF, and ENF, respectively. The proposed methods have been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. Statistical comparison of the results with the reference methods showed excellent agreement and indicated no significant difference in accuracy and precision.