Mostafa M. Emara

Development and Validation of a New GC–MS Method for the Detection of Tramadol, O-Desmethyltramadol, 6-Acetylmorphine and Morphine in Blood, Brain, Liver and Kidney of Wistar Rats Treated with the Combination of Heroin and Tramadol

Heroin is one of the most dangerous abused drugs in the world. Tramadol is an additive recently found at high concentration levels in street heroin seizures in Egypt. This substance could affect the usual analytical method for the detection of heroin and metabolites, as well as the pharmacokinetic and disposition of single analytes. One shortfall regarding this issue is present in the literature. This study describes a validated, simple, sensitive and selective method to determine tramadol, O-desmethyltramadol, 6-acetylmorphine and free morphine in the blood, brain, liver and kidney of Wistar rats, intraperitoneally treated with a combination of heroin and tramadol (10 and 70 mg/kg, respectively) using liquid-liquid extraction and gas chromatography-mass spectrometry detection. The calibration curves of tramadol, O-desmethyltramadol and 6-acetylmorphine in blood were linear in the concentration range from 25-5,000 ng/mL and morphine was found in the concentration range 50-5,000 ng/mL. The analytes were detected in all tested matrices, except 6-acetylmorphine, which was not detected in liver. The highest concentrations of tramadol and O-desmethyltramadol were observed in kidney (22,9381 and 28,498 ng/g), while 6-acetylmorphine and morphine were found at the highest levels in brain (3,280 and 3,899 ng/g, respectively). The present method is simple, rapid and sensitive and can be used to study the pharmacokinetics, disposition and interaction of these drugs in several animal models.

Silica coating and photocatalytic activities of ZnO nanoparticles: effect of operational parameters and kinetic study.

Silica-coating ZnO nanoparticles were prepared using the hydrothermal method. The prepared nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray Spectroscopy (EDX). It was found that ultrafine core/shell structured silica-coating ZnO nanoparticles were successfully obtained. TEM analysis revealed a continuous and uniform silica coating layer of about 8nm in thickness on the surface of ZnO nanoparticles. The photocatalytic performance of silica-coating ZnO core/shell nanoparticles in methylene blue aqueous solution was investigated. The effects of some operational parameters such as pH value, nanocatalyst loading and initial MB concentration on the degradation efficiency were discussed. Kinetic parameters were experimentally determined and a pseudo-first-order kinetic was observed. Thus, the main advantage of the coating is the stability of the photocatalysts and the better performance in acidic or alkaline solutions. Compared to ZnO the maximum apparent rate constant is obtained at pH 8.5 (pH 11.5 in case of bare ZnO). Moreover, the Langmuir adsorption model was applied to describe the equilibrium isotherm at different MB concentration. The applicability of the Langmuir isotherm suggests monolayer coverage of the MB onto surface of silica-coating ZnO nanoparticles. The kinetics of the adsorption with respect to the initial dye concentration, were also investigated. The pseudo-first-order and second-order kinetic models were used and the rate constants were evaluated. The kinetic studies revealed that the pseudo-second-order kinetic model better represented the adsorption kinetics, suggesting that the adsorption process may be chemisorption.

Structural modification of mordenite zeolite with fe for the photo-degradation of edta

Fe(2+) was incorporated inside mordenite through ion exchange technique in aqueous solution. The amount of Fe loading was 25-100 wt %, using FeSO(4).7H(2)O as precursor and Na-mordenite starting material Na-M. The Fe incorporated (Fe-M) thus prepared was characterized by XRD, FTIR and N(2) adsorption measurements. It was found that Fe mordenite retained the same structure as that for Na-mordenite which may indicate that Fe well dispersed into mordenite channels. BET indicated that Fe-M samples possessed higher surface area compared to the parent Na-M. Photocatalytic degradation of EDTA was carried out in presence of the prepared Fe-M catalysts. Effects of catalyst concentration and temperature were also studied. Thermodynamic parameters calculated for 50% Fe-M showed the highest catalytic activity toward EDTA degradation.

Thermodynamics of ionic-association in aqueous solutions of Ca and Mg organic salts using ion-selective electrode technique—II. benzoate, o-toloate, o-chlorobenzoate and salycylate

Abstract The stoichiometric association constants, K , the thermodynamic association constant, K A , and the other thermodynamic parameters such as Δ S °, Δ H ° and ΔG° for the association between each of the Ca and Mg ions with benzoate, o -toloate, o -chlorobenzoate and salycylate have been determined at 25°C, 35°C and 45°C in aqueous media. Ion-selective electrode technique has been used in the measurements of Ca and Mg ion activities The trend of association behavior of both Ca and Mg aromatic salts could not be explained on the basis of p K a of the mother organic acids but could be explained based on the trend of Hammet function σ of these salts themselves relative to the corresponding benzoate salt.

New HPLC Method to Detect Individual Opioids (Heroin and Tramadol) and their Metabolites in the Blood of Rats on Combination Treatment

Drug abuse is both an age-old and a constantly evolving problem in society. Trends in illicit drug use are highly fluid, with new formulations increasing in popularity. For this reason, methods for illicit drug detection and analysis need to be continually updated so they remain useful and relevant. A recent trend in street heroin production has seen it diluted with large amounts of tramadol in addition to the classical diluents such as acetaminophen and caffeine. This study describes a sensitive, simple and accurate high-performance liquid chromatographic method with ultraviolet detection for the simultaneous detection of heroin, 6-acetylmorphine, morphine, tramadol and O-desmethyltramadol in the blood of rats using a liquid-liquid back-extraction method. The separation was performed on LichroCART RP-18e with particle size of 5 µm (250 × 4.6 mm) with mobile phase acetonitrile-50 mM KH(2)PO(4) buffer, pH 7.1, using a gradient mode with a 1.0 mL/min flow rate. The calibration curves were linear in the concentration ranges 0.25-100 and 0.1-100 µg/mL for morphine and other analytes, respectively. Recovery values for the substances ranged between 59 and 83%. This technique was successfully used in pharmacokinetic studies measuring 6-acetylmorphine, morphine, tramadol and O-desmethyltramadol in the blood of rats intraperitoneally treated with a blend of 10 mg/kg heroin and 70 mg/kg tramadol. This technique shows promise for analysis of confiscated street heroin.

An Ion Selective Electrode Study of Calcium and Magnesium Sulfate in Aqueous Solution

Abstract A divalent cation-selective electrode was used to study the ion association thermodynamics of MgSO4 and CaSO4 at temperatures between 15 and 35 ° C and at various ionic strengths. The ionic strength was adjusted with sodium chloride because it is the major salt in most natural waters. The thermodynamic association constants for MgSO4 and CaSO4 compare well with those determined from conductance studies.

Preparation of Water-in-Diesel Fuel Nanoemulsions Using High-Energy Emulsification Method and a Study of Some of Their Surface Active Properties

In this work, formations of water-in-diesel fuel nanoemulsions using water/mixed nonionic surfactant/diesel fuel system has been studied. The high-energy emulsification method was used to form three emulsions using different water contents: 5, 10, and 14% (v/v) namely; E1, E2, and E3, respectively. These nanoemulsions were stabilized with emulsifiers having different hydrophilic lipophilic balance (HLB), namely, Span 80 (HLB = 4.3), Emarol 85 (HLB = 11), and their mixture (SE) with HLB = 10. The effect of water on the droplet size formation has been investigated. The interfacial tension and thermodynamic properties of the individual and emulsifiers blends have been studied. The interfacial tension (γ) measurements at 30°C were used to determine the critical micelle concentration (CMC) and surface active properties of these emulsifiers. The water droplet sizes were measured by dynamic light scattering (DLS). From the obtained data, it was found that mean sizes between 19.3 and 39 nm were obtained depending on the water content and concentration of blend emulsifiers (SE). Also, the results show that the interfacial tension (γ) gives minimum value (10.85 mN/m) for SE comparing with individual emulsifier (17.13 and 12.77 mN/m) for Span 80 and Emarol 85, respectively. The visual inspection by transmission electron microscopy showed that the obtained results support the data obtained by dynamic light scattering.

Thermodynamics of ionic-association in aqueous solutions of Ca and Mg organic salts using ion-selective electrode technique—I. Formates, acetates, propionates and butyrates

The divalent selective electrode together with high precision solid state, digital pH -mv -meter makes broader application of potentiometry in physical and inorganic chemistry a certainty. The above set-up is used to determine the stoichiometric constants, K, for Ca and Mg ions association with formates, acetates, propionates and butyrates at 25°, 35° and 45°C in aqueous media. The K-values were converted to infinite dilution KA values were found to be 8.4 LM−1, 10.4 LM−1, 19.1 LM−1 and 19.3 LM−1 for calcium salts of formate, acetate, propionate and butyrate respectively. Also KA values for Mg salts of formate, acetate, propionate and butyrate were found to be 7.8 LM−1, 9.5 LM−1, 13.1 LM−1 and 13.1 LM−1 respectively. Other thermodynamic parameters such as ΔG°, ΔH° and ΔS° are also obtained from the variation of KA with temperature for each salt. The data are interpreted relative to each other on basis of pKa of the corresponding organic acid. Their temperature behaviour is similar to those salts derived from strong acids such as sulphates, rather than weak acids.

Copper modified exchanger for the photodegradation of methyl orange dye

AbstractA Cu modified hybrid exchanger was synthesized by loading Cu(II) onto the sulfonic acid sites of the C-145 cation exchanger by passing CuSO4 solution followed by treatment with sodium hydroxide to deposit the copper hydroxide particles. Each hybrid sorbent particle is essentially a spherical macroporous cation exchanger bead within which agglomerates of nanoscale hydrated Cu oxide particles have been uniformly and irreversibly dispersed using a simple chemical–thermal treatment. The obtained material was characterized using X-ray diffraction, energy-dispersive X-ray spectroscopy and scanning electron microscope. The obtained materials were applied for the photo-decolorization of methyl orange as a member of the azo dye family, in an aqueous medium using UV irradiation (λ = 254 nm) under different experimental conditions. The effect of catalyst concentration and pH on the decolorization of methyl orange dye was investigated. The decolorization of methyl orange dye has been followed using UV–vis spe...

The dynamics of micelle formation in bile salts I. Sodium cholate and sodium deoxycholate

Abstract It has been found that two bile salt solutions of NaC (trihydroxy cholanic salt ) and NaDC (dihydroxy cholanic salt have an excess ultrasonic absorption . This excess absorption fits a single relaxation in all cases . To explain this observed single relaxation the data are considered in terms of several existing models. Simple cation-anion reactions to form a monomer salt are ruled out on the grounds that our experimentations are carried out at concentrations far above the critical micelle concentrations (CMC). A second approach in which the excess absorption is attributed to micelle- counter ion reaction. The third existing model deals with an equilibria between the micelles and the monomers of the bile salts. Three different types of models emerge from this kind of equilibria. Only two (3a and 3b ) of them can be considered as a feasible possibility to explain part of the results.