Mahmoud A. Alawi

Organochlorine pesticide contaminations in human milk samples from women living in Amman Jordan.

Concentrations of 15 organochlorine pesticides were determined by capillary gas chromatography in 59 human milk samples collected from the general population during 1989/1990 in the Jordanian capital of Amman. In addition to hexachlorbenzene (HCB), three groups of organochlorine compounds namely, DDT and its metabolites, hexachlorcyclohexane (HCH-isomers) and the cyclopentadiene group (aldrin, dieldrin, endrin, heptachlor, and heptachlor epoxide) were analyzed.The results show that almost all samples contained HCB, β-HCH, p,p′-DDE and p,p′-DDT, whereas p,p′-DDD, heptachlor, α-HCH, γ-HCH and o,p′DDT were found in 42, 40, 33, 22 and 20 analyzed samples, respectively. The concentration of HCB, β-HCH, p,p′-DDE, p,p′-DDT and heptachlor expressed on a milk-fat basis (median in mg/kg milk fat): 0.29, 0.4, 2.04, and 0.7 respectively.For the comparative purposes and in order to try to find the possible sources of mother-milk contaminations, different types of locally produced and imported cow milk samples were also analyzed for the same organochlorine compounds. Almost all types of tested milk were contaminated with p,p′-DDE.

Simultaneous determination of amlodipine and atorvastatin with its metabolites; ortho and para hydroxy atorvastatin; in human plasma by LC–MS/MS

A simple liquid chromatography/ion trap mass spectrometry method for the quantification of amlodipine and atorvastatin with its metabolites, ortho and para hydroxy atorvastatin, simultaneously in human plasma was developed. Analytes with internal standard were extracted by protein direct precipitation with acetonitrile. Adequate chromatographic separation was achieved using Phenomenex Synergi 4u polar-RP 80A (150mm×4.6mm, 4μm) column in the isocratic elution mode and the eluent was water/methanol (14:86%, v/v) adjusted by trichloroacetic acid to pH 3.2 which was delivered isocratically at constant flow rate of 0.50mL/min. Standard solutions for the analytes were prepared using amlodipine besylate, atorvastatin calcium, ortho-hydroxy atorvastatin dihydrate monosodium salt, para-hydroxy atorvastatin disodium salt, and pravastatin sodium as an internal standard. The method validation intends to investigate specificity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability according to USFDA guideline. Standard calibration levels were prepared by pooled human plasma to attain final dynamic range of 0.2-20.0ng/mL for amlodipine, 1.5-150ng/mL for atorvastatin, 1.0-100.0ng/mL for ortho-hydroxy atorvastatin and 0.2-20.0ng/mL for para-hydroxy atorvastatin. Clinical bioequivalence study was successfully investigated by the application of this validated bioanalytical method in order to evaluate bioequivalence of two commercial products 10mg amlodipine/80mg atorvastatin in a single dose. In this study, 29 healthy volunteers were participated in randomized, two periods, double blend, open label cross over design. Pharmacokinetic parameters of C(max), AUC(0-t) and AUC(0-∞) were calculated to compare a test product with CADUET(®) reference product.

Interaction behavior of organochlorine pesticides with dissolved Jordanian humic acid

The interaction behavior of Jordanian humic acid isolated from the sediment of King Talal Dam with some chlorinated pesticides (tetradifon, p,p′-DDE and p,p′-DDT) was studied under different experimental conditions, namely: humic acid concentration, pH, and temperature. The synergistic effect was also studied. The amount of pesticide that did not interact was determined by extraction and analysis by gas chromatography.The interacted amount of pesticide was directly proportional to the concentration of soluble humic acid and inversely proportional to pesticide polarity. There was no significant change in the interacted amount of pesticide with respect to change in temperature. With pH increase, there was a small decrease in the interacted amount of tetradifon, while no changes were detected for p,p′-DDE and p,p′-DDT.

Determination of trihalomethanes produced through the chlorination of water as a function of its humic acid content

Pure humic acid was isolated from Azraq Oasis sediments in the east of Jordan. Different concentrations of humic acid solutions, under different experimental conditions were analyzed for trihalomethanes (THMs), using different concentrations of hypochlorite ion as the chlorinating agent. The analysis of the THMs was done by capillary gas chromatography equipped with a 63Ni-electron capture detector. The presence of trihalomethanes in drinking water from some sites in Jordan was also studied, and some treatment techniques were attempted that could be used for reducing or eliminating trihalomethanes from drinking water.

Separation of Polyphenols from Jordanian Olive Oil Mill Wastewater

This research aims at separation of polyphenols from Jordanian olive mill wastewater which have possible applications in pharmaceutical industry. The phenolic compounds were isolated using silica column chromatography based on using different solvents after extracting the acidified solution with n-hexane and ethyl acetate. The structural elucidation of the separated compounds was achieved using 1H-NMR, 13C-NMR and mass spectrometry. The concentrations of these compounds were determined by GC-MS after derivatization with N, O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). The concentrations of the main isolated phenolic compounds in the Jordanian olive mill wastewater were ferulic acid (93.6 mg/L), trans-cinnamic acid (105.3 mg/L), p-coumaric acid (117.0 mg/L), vanillic acid (128.7 mg/L), caffeic acid (140.4 mg/L), tyrosol (210.6 mg/L), and hydroxytyrosol (315.9 mg/L).

Dioxins and furans in the Jordanian environment Part 1: Preliminary study on a municipal landfill site with open combustion nearby Amman - Jordan

Polychlorinated dibenzo-p-dioxin and dibenzofuran concentrations in samples collected from the open-burnt municipal landfill site at Marka/Amman were analyzed. Six samples were collected from different locations distributed over the area of the landfill. The PCDD/PCDF concentrations ranged from 8.2 to 1,470 ng TEQ (BGA)/kg d.w. The total concentrations of PCDD/PCDF were between 685 and 112,300 ng/kg d.w. It was found that in all waste samples the total concentrations increased from Octa-CDD to Tetra-CDD and from Octa-CDF to Tetra-CDF.

Catecholamines in Drosophila melanogaster (wild type and ebony mutant) decuticalarized retinas and brains.

The concentrations of catecholamines were determined in the decuticalarized retinas and brains at different ages in wildtype and ebony Drosophila melanogaster using the HPLC‐technique with an electrochemical detector. L‐Dopa, dopamine (DA), α‐methyldopa (α‐MD) and unidentified compounds X1, X2 and X3 were found in decuticalarized retinas and brains of wildtype and ebony at different ages. Retinas and brains of the mutant ebony have higher concentrations of L‐Dopa, DA and α‐MD than the wildtype. In both wildtype and ebony, the concentrations of X1, X2 and X3 were found to be higher in decuticalarized retinas than in brains. The identity and importance of X1, X2 and X3 are still unknown.

Study of polycyclic aromatic hydrocarbons (PAHs) in soil samples from Al-Ahdab oil field in Waset Region, Iraq

Abstract Levels of thirteen polycyclic aromatic hydrocarbons (PAHs) were studied in 24 soil samples collected from the Ahdab oil field in Waset region, Iraq. The whole analysis was carried out using the gas chromatography with mass spectrometry (GC/MS) in the single ion monitoring (SIM)-mode. The total PAHs concentrations were ranged between 19 μg/kg (Site 15) and 855 μg/kg (Site of 16). The results of these samples were compared among each other according to their toxicity equivalence in μg TEQ/g concentrations and with the results of other studies. The total estimated cancer risks of exposure to PAHs in soil samples were ranged from 1.02 × 10−7 to 4.59 × 10−6. By multiplying the estimated cancer risk values by 106, then the estimated theoretical cancer cases per million is between 0.0 and 5. The total estimated cancer risks in this study were within the acceptable range of excess cancer risk specified by the Environmental Protection Agency in the United States.

Method development, validation and bioequivalence of varenicline in human plasma by liquid chromatography tandem mass spectrometry

A method based on liquid chromatography coupled to tandem mass spectrometry was developed for quantitative determination of varenicline in human plasma. Varenicline and the internal standard (25.0ng/mL of Clarithromycin) were extracted from human plasma by liquid-liquid extraction, using methyl tertiary butyl ether as the organic solvent. The chromatographic separation was achieved using C8 column with isocratic elution using a mixture of acetonitrile:0.001M ammonium acetate (adjusted to pH 4.0) (70:30%, v/v). The method was validated over the concentration range of 0.1-10.0ng/mL by investigating specificity, sensitivity, linearity, precision, accuracy, recovery, matrix effect and stability according to United State Food and Drug Administration guideline. The validated bioanalytical method was successfully applied to evaluate bioequivalence of two commercial products of 1mg varenicline single dose.

Dioxins and furans in the Jordanian environment part 2: Levels of PCDD and PCDF in human milk samples from Jordan

Thirty individual human milk samples were gathered from five main towns in Jordan. They were mixed to six pooled samples and analyzed for PCDD and PCDF. All examined samples were contaminated with 1,2,3,4,6,7,8-HeptaCDD (3.2-96.0 ng/kg fat) and OctaCDD (29.0-147 ng/kg fat). The calculated TEQ (BGA)-values range between 0.26 and 60.32 ng TEQ/kg fat, which are all above the calculated tolerable concentration of 0.19 ng TEQ/kg milk fat.