Hutaf M. Baker

Determination of decabromodiphenyl ether in backcoated textile preparation.

A simple and reproducible chromatographic method for determination of decabromodiphenyl ether (DBDPE) is presented. The mobile phase consisted of aqueous acetonitrile solution. A simple quantitative extraction method using a soxhlet extraction is proposed to extract decabromodiphenyl ether from textile backcoated sample, and, a rapid chromatographic method using spectrophotometric detection, is described for the determination of decabromodiphenyl ether. The proposed method is applied for the determination of the decabromodiphenyl ether in a backcoated textile. Complete methods validation for both the extraction and analytical methods are discussed. Linear calibration curve in a range of 0.3-300.0mg/microL is achieved with a detection limit of 0.1microg. The method is successfully applied to the determination of decabromodiphenyl ether in several backcoated formulations.

Synthesis and characterization of metal 2-pyridine carboxaldehyde-N-methyl-N-2-pyridyl hydrazone complexes and their microbiological activity

Complexes of Cu(II), Mn(II), Co(II), Ni(II), Hg(II), Cd(II) and Rh(III) with 2-pyridine carboxaldehyde-N-methyl-N-2-pyridylhydrazone ( pamph) have been prepared and characterized. The new complexes have been characterized by elemental analysis, conductivity and magnetic measurements, IR, UV–vis and 1H NMR spectroscopic methods. The microbiological activity of the complexes was investigated against bacteria and fungi. Most of the complexes studied appear to be active against bacteria while all are active against fungi. The Cu, Cd and Hg complexes exhibit the highest activity against both bacteria and fungi.

Kinetics of the Oxidation of L-Cysteine by trans- and cis-Cobalt(III) and Iron(III) Complexes

Kinetics of oxidation of L-cysteine by pairs of trans and racemic cis isomers of cobalt(III) and iron(III) based transition metal complexes have been studied in aqueous solution. Kinetics measurements were run under pseudo first order conditions in which the concentration of cysteine is between one and two orders of magnitude greater than that of the isomers of the transition metal complex. The orders of the reaction with respect to both cysteine and the isomer were determined. The observed rate constants and the overall rate constants of the oxidation process were measured. For all geometrical isomers, it was found that the rate constant of oxidation of L-cysteine by the trans isomer is between one to three orders of magnitude greater than that by the cis isomer. The difference in rates can be explained by a geometric factor around the metal ion center in the complex. The less crowded isomer (trans) makes electron transfer easier and hence facilitates the oxidation process which leads to a higher oxidation rate.

Evaluation of Jordanian treated natural zeolite for the uptake of p-nitrophenol from wastewater by continuous column method

AbstractIn this study, removal of p-nitrophenol (PNP) onto Jordanian zeolite was investigated. The surface of the calcinated zeolite (CZ) was modified using urea (CZU) and thiourea (CZT).The experiments of the removal were carried out under different operating conditions in column reactor. A pseudo-second-order, intraparticle diffusion, and Elovich kinetic models were investigated to predict the rate constants and equilibrium capacities for this process. The results showed that the removal of PNP highly fitted the pseudo-second-order for the three adsorbents which provides the best correlation of the experimental data. The activation energies were calculated using the rate constants of the pseudo-second-order kinetic model, the Ea values for CZU, and CZT were found to be small, since the process is an exothermic one, which may be as physical and chemisorptions.

Analysis of Lead and Cadmium in Selected Leafy and Non-Leafy Edible Vegetables Using Atomic Absorption Spectrometry

Sixteen leafy and non-leafy edible vegetables were collected from the Northern Al-gour area, Jordan, and analyzed for Pb and Cd using atomic absorption spectrometry. In addition, soil samples were collected from areas adjacent to the sites from which the vegetables samples were collected and about 40 m from the road. Results indicated that the average Pb and Cd concentrations in the selected edible vegetables were found in the following order: Leaves > roots > fruits > seeds. Moreover, Pb and Cd levels in soil samples collected from the near main road were higher than those soil samples collected from the sites 40 meters far from the main road.