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Owing to the increase of pollutant sources in oceans, seas, and lakes, there is an expected effect on growth and metabolism of planktonic algae which are considered primary producers in the ecosystem. Therefore, it becomes urgent to carry out laboratory studies to test to what extent these pollutants can affect the growth of algae which is necessary as a food for marine fishes. Spirulina is considered the most important algal species due to its high nutritional value for humans and animals. Therefore, this work investigated the effect of different concentrations of Ni2+, Zn2+, and Cu2+ metal ion pollutants on growth of the blue-green alga Spirulina platensis. EC50 was identified to be around 2 mg/l for the three heavy metals. The suitability of Idku Lake for Spirulina platensis growth was investigated using multi-criteria spatial modeling integrated with remotely sensed data processing. Spatial distribution maps of turbidity, water nutrients, and phytoplankton were the input criteria used to assess Idku Lake’s suitability. The results obtained proved that low concentrations of the tested heavy metals stimulated growth and pigment fractions (chlorophyll a, carotenoids, and total phycobilins content) but to different degrees. The inhibitory effect was more prominent in the case of copper ions than zinc and nickel ions with all concentrations used. The overall suitability map of Spirulina platensis in Idku Lake showed that the whole lake is suitable for growth and proliferation except for the northwestern corner due to the high salinity levels. The present paper helps to understand the behavior of algae responding to environmental pollution, which supports environmental planners with the necessary baseline for investigating the fate of pollutants and the potential risk.

This study focused on the effect of five different concentrations of three heavy metals (Nickel, Copper and Zinc) on growth, IR spectra, the content of fatty acids and total soluble protein profile in Spirulina platensis. Spirulina platensis was selected for this study because of its high nutritional value as an important form of algae that is used commercially (especially for fish feeding) as a source of proteins, minerals, amino acids, vital unsaturated fatty acids, and a range of vitamins. EC50 of the three heavy metals was recorded nearly at concentration 2.0 mg/l. The inhibitory effect of growth measured in optical density was more prominent in case of copper than zinc and nickel. IR spectra showed formation of new compounds and absence of other compounds when compared to untreated cells, it was clearer in case of Cu2+ than in case of Zn2+ and Ni2. Grand total fatty acids decreased under all the tested concentrations, saturated fatty acids were more dominant than unsaturated ones under stress conditions. The destructive effect of the heavy metal ions on protein profile was more prominent under the stress effect of Cu2+ than in case of Zn2+ and Ni2+.

Rapid-acting inhaled (Afrezza) and injected mealtime insulins are available for patients with type 2 diabetes who are also treated with basal insulin. In this interim analysis of a single-site, observational, investigator initiated study, time spent in glycemic goal range (70-180 mg/dL) without significant hypoglycemia (primary endpoint) was assessed in the intent-to-treat population of patients with type 2 diabetes (N=25; 60%M; age 62y; wt 95.7±4.4kg; A1c 8.3±0.2%). Patients were titrated from pre-meal insulin plus basal insulin to inhaled insulin plus basal insulin over 2 weeks and followed for 14 weeks. At Week 14, mean (±SE) times spent above (>180 mg/dL; -1.7±3.2 mins; P=0.60), in (70 180 mg/dL; -1.2±2.6 mins; P=0.65), and below (60 units/day inhaled insulin. Although this interim analysis did not achieve its primary endpoint of significant increase of time spent in glycemic goal range, possibly caused by patients not self-adjusting post-prandial dosing as instructed. Patients treated with inhaled insulin with background basal insulin for 14 weeks experienced significant reduction of A1c and significant improvements of Useful, Freeing, and Difficult QoL subdomains compared to baseline. Disclosure M. Kipnes: None. A. Salhin: None. T. Ryan: None. J. Vadakekalam: None. V. Pamar: None. F. Trigoso: None. F. Akhrass: None. Funding MannKind Corporation

Objective: the present paper aims to explore the main motives behind Cairo bank’s attempts to raise its senior bankers’ level of organizational resilience. Methodology: after gathering and investigating all relevant literature about organizational resilience, semi-structured interviews were conducted with 24 of the senior bankers who work at Cairo bank at 6 October city, Giza, Egypt. All interviews were conducted in the Arabic language. Findings: the findings of this study show that senior bankers at Cairo bank, like many other Egyptian classes, struggle in a state of uncertainty and consider it the main motive behind their bank’s attempt to raise their resilience level. The pressure of stakeholders is, to a large extent, present, and there is a thought that fulfilling different societal obligations is a source for economic gains and accordingly, stakeholders’ pressure is a second motive behind raising employees’ organizational resilience. Furthermore, organizational culture adaptability and the tendency to responsively act in line with unpredicted events is a third motive. Finally, senior bankers’ loud voice in calling for continuous grants for education and training has come to be the fourth motive. Value added: the paper is considered the first to qualitatively investigate organizational resilience in Egypt. Recommendations: The researchers are of the view that the development of every departmental agenda for needed resilience is a priority for improving organizational capacity. Moreover, reformulating the bank’s values, operations and activities should also be considered to create a harmony between the external threats and the internal duties. Furthermore, there should be also an orientation to redefine the concept of “uncertainty” from time to time to include socio-political and socio-economic types of risk.

This paper investigates the relationship between managerial sentiment and sector returns. Using UK monthly data from January 1985 to December 2014 and a sample of consumer and business confidence indicators provided by the European Commission, we provide novel evidence on how managerial and consumer sentiment indicators affect stock returns. We find no support for consumer confidence as a predictor of stock returns. However, managerial sentiment shows a significant impact on aggregate market and sector return indices. Furthermore, we find that parameter estimates for sector groupings are not consistent, implying that the sentiment-return relationship differs across sectors. We also find parameters are sensitive to industry characteristics. Importantly, the overall sentiment-return relationship is dominated by sentiment associated with manufacturing firms.

Novel aromatic embedded Schiff bases have been synthesized in ionic liquid [bmim]Br and evaluated in vitro for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibitory activities. Among the newly synthesized compounds, 5f, 5h and 7j displayed higher AChE enzyme inhibitory activities than standard drug, galanthamine, with IC50 values of 1.88, 2.05 and 2.03μM, respectively. Interestingly, all the compounds except for compound 5c displayed higher BChE inhibitories than standard with IC50 values ranging from 3.49 to 19.86μM. Molecular docking analysis for 5f and 7j possessing the most potent AChE and BChE inhibitory activities, disclosed their binding interaction templates to the active site of AChE and BChE enzymes, respectively.

A class of second order nonlinear damped differential equations is studied and several new oscillation conditions are obtained. Our results extend, improve and unify a number of existing results and handle the cases which are not covered by known criteria.

Reinforced concrete beams were subjected to the combination of mechanical loading and alkali-silica reaction (ASR) in order to investigate the durability of concrete under their combined action. This experiment used locally-sourced materials such as aggregates and admixtures in order to develop a concrete mix that will give the optimum resistance to such combined action. Half of the specimens were subjected to static, and cyclic loading and exposure to accelerated ASR-inducing environment and the other half were exposed only to an ASR-inducing environment. The test results indicate that the expansion due to the combined action was significantly different from that in specimens exposed only to a high-alkaline environment. The micro and macro cracks induced by cyclic loading form paths leading to an increased ASR rate, while the macro-mechanical cracks provide regions of relatively free expansion, as can be deduced from the decreasing crack widths.

New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (k(b)=5.03-33.00×10(5) M(-1)) for L1-L3 and L5 and (6.14-9.47×10(4) M(-1)) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency.

Six new platinum(II) complexes of a thiosemicarbazone Schiff base with isatin moiety [PtL1 to Pt(L6)2] were synthesized by the reaction of platinum(II) with the following: (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide [L1H], (Z)-2-(5-methyl-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide [L2H], (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide [L3H], (Z)-N-methyl-2-(5-nitro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide [L4H], (Z)-N-methyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide [L5H], and (Z)-N-ethyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide [L6H]. The structures of these complexes were characterized by elemental analysis, IR, UV–Vis, 1H NMR, and mass spectrometry analyses. The structure of Pt(L6)2 was further characterized by single-crystal XRD. The interaction of these complexes with calf thymus (CT) DNA exhibited a high intrinsic binding constant (Kb = 3.5 × 104 to 3.29 × 106 M−1), which reflected the intercalative activity of these complexes toward CT DNA. This result was also confirmed by viscosity data. Data obtained from the in vitro anti-proliferative study clearly established the anticancer potency of PtL1, PtL2, PtL3, PtL5, and Pt(L6)2 against the human colorectal carcinoma cell line HCT 116.

This study involves a simple and low cost chemical method for the synthesis of Gallium Nitride (GaN) nanoparticles at low temperature. Structural and optical characterizations were carried out using various techniques in order to investigate the properties of the nanoparticles. The Field-Emission Scanning Electron Microscope (FESEM) images showed that the nanoparticles consist of cubic and hexagonal shapes, indicating crystallized structural quality of the GaN nanoparticles. The average size of the nanoparticles was found to be 51 nm. The X-ray Diffraction (XRD) and Raman analysis further confirmed the hexagonal and cubic phases of GaN nanoparticles. The room temperature photoluminescence deduced h-GaN energy gaps of 2.95, 3.12 and 3.13 eV.

This study involves the synthesis of indium nitride (InN) nanoparticles at low temperature using a chemical method. The synthesized InN nanoparticle exhibited high quality crystalline cubic phases with In2O3 impurity. The average diameter of the cubic phases ranges from 11.4 nm to 21.4 nm. The energy gap of the synthesized InN nanoparticle is approximately 0.97 eV. Under illuminasion (30 mW/ cm 2 ) the n-InN/p-Si (1 1 1) hetro-junction solar cells displayed a short circuit current of 1.2 mA and power-conversion efficiency of 1.09%. This work demonstrates the first successful synthesis of n-type InN nanoparticles at low temperature using a chemical method. This novel approach is an important breakthrough in the development of InGaN-based full-solar-spectrum photovoltaic. 2013 Elsevier Ltd. All rights reserved.

The free fatty acids (FFA) in palm oil were determined by flow injection titrimetric method using salicyladhyde-2,4-dinitrophenylphenylhydrazone (SDPH) as a new coloring reagent. The compound was synthesized and its structure was established using different spectroscopic data. It exhibited sensitive colour changes in basic medium and absorb at 482 nm. Single-line manifold using SDPH as indicator was developed. Flow injection operating parameters such as carrier, reagent concentration, flow rate, size of mixing chamber and injection volume were optimized. The method is recommended for the determination of oil samples with acidity degree (a.d.) higher than 0.5 a.d. Twelve oil samples were tested using the appropriate FIA manifold and the obtained results were compared to the standard PORIM method. Good correlation (r2 = 0.99) between the two methods was obtained.

Regulating the licensing and practice of healthcare professions is an essential first step for reforming the Libyan healthcare system. In this article, we identify the overarching principles that should guide any efforts targeted at reforming the regulation of healthcare professions in Libya, and to summarize the perspective of the Libyan Healthcare Society-USA (LHS-USA) on these issues. Our aim is not to advocate for the adoption of a specific regulatory model. Instead, we hope to stimulate debate about the principles of professional regulation, and over the process needed to develop consensus on the final shape of the Libyan regulatory model. Key words: Healthcare, Libya, Licencing, Profession, Regulating.

Thiosemicarbazones of 2-amino-5-chlorobenzophenone and 3-aminobenzophenone (L 1 –L 4 ) have been synthesized and their Cu(II) complexes ( 1 – 4 ) were afforded via coordination with cupric chloride. All these compounds were characterized by UV–vis and IR spectroscopy together with CHN elemental analysis. NMR spectroscopy was also applied to characterize the ligands. In vitro cholinesterase inhibitory assays for the complexes ( 1 – 4 ) showed IC 50 values less than 10 μmol/L, with complex 1 exhibiting the most activity, IC 50 = 2.15 μmol/L and 2.16 μmol/L for AChE and BuChE, respectively. Molecular modeling simulation revealed the binding interaction template for complex 1 with the AChE and BuChE receptors. In DPPH assay, the complexes also showed more in vitro antioxidant activities in comparison to their parent ligands.

A novel glassy carbon electrode (GCE) modified with a composite film of poly (4-vinylpyridine) (P4VP) and multiwalled carbon nanotubes (P4VP/MWCNT GCE) was used for the voltammetric determination of paracetamol (PCT). This novel electrode displayed a combined effect of P4VP and MWCNT on the electro-oxidation of PCT in a solution of phosphate buffer at pH 7. Hence, conducting properties of P4VP along with the remarkable physical properties of MWCNTs might have combined effects in enhancing the kinetics of PCT oxidation. The P4VP/MWCNT GCE has also demonstrated excellent electrochemical activity toward PCT oxidation compared to that with bare GCE and MWCNT GCE. The anodic peak currents of PCT on the P4VP/MWCNT GCE were about 300 fold higher than that of the non-modified electrodes. By applying differential pulse voltammetry technique under optimized experimental conditions, a good linear ratio of oxidation peak currents and concentrations of PCT over the range of 0.02–450 μM with a limit of detection of 1.69 nM were achieved. This novel electrode was stable for more than 60 days and reproducible responses were obtained at 99% of the initial current of PCT without any influence of physiologically common interferences such as ascorbic acid and uric acid. The application of this electrode to determine PCT in tablets and urine samples was proposed.

A Schiff base, (E)-ethyl-4-(2-oxoacenaphthylen-1(2H)-ylideneamino)benzoate, (E4AB) had been synthesized in good yield by the acid-catalyzed condensation reaction of acenaphthenequinone and ethyl-4-aminobenzoate in methanolic solution. The synthesized compound was elucidated by elemental analysis (CHN), FTIR, 1H-NMR, 13C-NMR and single crystal X-ray diffraction. E4AB crystallized in the monoclinic crystal system with space group P21/c, Z = 4, V = 1569.3(2) ?3 and unit cell parameters a = 9.1589(8) , b = 21.2003(17)?, c =8.4502(7) ?, β= 106.972(2)°. The crystal structure of the compound is stabilized by intermolecular C-H···O hydrogen bonds and weak intermolecular π···π interactions. The title compound had been tested for the antimicrobial activity against Bacillus subtilis (B. subtilis), Enterobacter and Fusarium oxysporum f. sp. Cubense (Foc) by disc-diffusion method. E4AB is relatively active against Foc which is a pathogen that cause Wilt disease (also well known as Panama disease) in banana plantation.

A benzophenone substituted semicarbazone, 2-((3-aminophenyl)(phenyl)methylene)hydrazinecarboxamide (APHC) had been synthesized in good yield by the condensation of 3-aminobenzophenone and semicarbazide hydrochloride. The title compound was elucidated by elemental analysis (CHN), FTIR, 1 H and 13 C-NMR, 1 H- 1 H COSY, TGA and single crystal X-ray diffraction. The compound crystallized in the orthorhombic crystal system with space group of Pccn, Z = 32, V = 10375.1 (2) A 3 , and lattice constants a = 12.3855 (1) A, b = 34.5746 (5) A, c = 24.2283 (3) A and γ = β = α = 90˚. The molecular view shows that APHC contains four molecules of each species in the asymmetric unit, with similar geometries. However, there is no intramolecular hydrogen bond found in the crystal structure of the synthesized compound. X-ray diffraction also reveals that the molecule of the semicarbazone exists as a Z isomer with respect to the C=N.

A simple method for the determination of paracetamol (acetaminophen) with sodium 1,2-naphthoquinone-4-sulphonate (NQS) in alkaline medium using flow injection analysis (FIA) was developed and validated. The effect of variables such as flow rate, NQS concentration, reaction coil length, NaOH concentration, and detection wavelength were studied. Linear response was found over the concentration range 3–35 mg L−1 (r2 = 0.9995), the relative standard deviation from replicate injections (n = 9) of 20 mg L−1 of paracetamol was 0.89%. A sampling rate of 82 samples h−1 was obtained. The method was applied for the determination of paracetamol in pharmaceutical tablets, and results have been compared with those obtained by the official method.

A flow injection analysis (FIA) incorporating a thiosemicarbazone-based coated wire electrode (CWE) was developed method for the determination of mercury(II). A 0.1 M KNO3 carrier stream with pH between 1 and 5 and flow rate of 1 mL·min−1 were used as optimum parameters. A linear plot within the concentration range of 5 × 10−6–0.1 M Hg(II), slope of 27.8 ± 1 mV per decade and correlation coefficient (R2) of 0.984 were obtained. The system was successfully applied for the determination of mercury(II) in dental amalgam solutions and spiked environmental water samples. Highly reproducible measurements with relative standard deviation (RSD < 1% (n = 3)) were obtained, giving a typical throughput of 30 samples·h−1.

To understand data and present findings appropriately, researchers need awareness of statistical techniques. This chapter discusses the statistical tools used to analyse data collected. It focuses on two sets of the most widely used statistical tools, as shown in the ‘Deductive’ section in the data analysis area of the Methods Map (see Chapter 4): (1) exploring relationships and (2) comparing groups. In addition, we briefly explain ‘Big Data’.

Hg(II) has formed a soluble complex with 4-(dimethylamino) benzaldehyde-4-ethylthiosemicarbazone (DMABET) in methanol with a molar ratio of mercury(II):DMABET of 1 : 4. The formation constant (Kf) and Gibbs free energy (~G) of the complex showed that the formation of the complex was favorable. The DMABET was investigated as ionophore for Hg(II)-ion selective electrode (ISE). At optimum pH 1–5 the proposed Hg(II)-ISE showed an almost Nernstian slope at 27.8 � 1 mV, with linear regression coefficient, R 2 = 0.995 and a detection limit of 5 � 10 � 6 M. There was no serious interference from silver(I) with selectivity coefficient 5.69 � 10 � 3 . The electrode life span was more than 3 months. It has been applied for real water sample analysis and the results were in good agreement with the standard method.

Copper indium gallium diselenide (CIGS) films were deposited as an absorber layer on polyethylene terephthalate (PET) substrates by a screen printing technique using CIGS ink with a Ga content ranging from 0.3 to 0.6. The melting point of PET substrate is 254.9 °C; the average transmission in the visible (400 nm–800 nm) for PET substrates is greater than 85%. Effects of Ga content of the CIGS absorber layer on structural and electrical properties of the CIGS films were studied. The lattice parameters, a and c for all CIGS films were decreased with increasing Ga content. At room temperature, Hall mobility and charge-carrier concentration of the CIGS films varies from 97.2 to 2.69 cm2 V−1 s−1 and 9.98×1016 to 3.23×1018 cm−3, respectively.

Chalcopyrite copper indium gallium diselenide (CIGS) ink was prepared by dissolving copper, indium, gallium acetylacetonate and Se powder in oleylamine using the hot injection methods. CIGS films were deposited on a PET plastic substrate by a screen-printing technique using CIGS ink with a Ga content ranging from 0.3 to 0.6. X-ray diffraction patterns reveal that the films exhibit a chalcopyrite-type structure. The crystalline grain sizes of the films decrease with increasing Ga content. AFM data shows that the root mean square (RMS) surface roughness of the CIGS film decreases with increasing Ga content. The effects of the Ga content in the CIGS absorber layer on the optical properties of the corresponding thin films and solar cells were studied. The band-gap energies of the CIGS thin films increased with an increasing Ga/(In+Ga) ratio. The short-circuit current (ISC) of the solar cell decreased linearly with the Ga/(In+Ga) ratio, while the open-circuit voltage (VOC) increased with this ratio. The solar cell exhibited its highest efficiency of 4.122% at a Ga/(In+Ga) ratio of 0.3.

CIGS nanoparticles ink with composition of Cu (Ga0.3 In0.7) Se2 was prepared by using dissolved copper, indium, gallium acetylacetonate, and Se powder in oleylamine using hot injection methods. The structural properties of the CIGS films deposited on the polyethylene terephthalate (PET) substrate were studied using an X-ray diffraction technique. The as-deposited CIGS films were found to be a chalcopyrite-type structure with crystallite grain size of about 43.8 nm. An optical study shows that the band-gap energy of the CIGS film is 1.25 eV. The flexible CIGS solar cell on a PET substrate with the best conversion efficiency of 4.21% is demonstrated.

Eight hydrazone-based ligands were synthesized, trapped in a silica sol–gel matrix, and were subsequently used in the micro-solid phase extraction (μ-SPE) of biogenic amines (BAs). The BAs investigated were tryptamine, phenylethylamine, putrescine, histamine, tyramine and spermidine. Prior to the extraction, dansyl chloride was added to the samples which were heated to 70 °C for 10 min. The samples were extracted with μ-SPE, after which analytes were desorbed using acetonitrile via ultrasonication. The extracts were analysed by high performance liquid chromatography (HPLC) with ultraviolet detection. Of the eight ligands investigated as sorbents, benzophenone 2,4-dinitrophenylhydrazone was found to be the most promising. The enhanced π–π interaction between the analytes and the ligand facilitated the adsorption process. Under the most suitable extraction conditions, the method demonstrated good linearity with correlation coefficient of more than 0.985 over a concentration range of 1–50 μg L −1 . Satisfactory repeatability with relative standard deviations of 7.43–11.30% ( n = 3) were obtained. Detection limits ranged from 3.8 to 31.3 ng L −1 . The μ-SPE method exhibited lower recoveries (71.5–87.4%) when compared to the solid phase extraction technique (79.7–95.0%), but enrichment factors of 94–460 were obtained. The proposed μ-SPE-HPLC method was applied to the determination of BAs in orange juice purchased from local supermarkets, with satisfactory results. The orange juices were characterized by the presence of relatively high levels of putrescine (range, 550–2210 μg L −1 ) but tryptamine and phenylethylamine were not detected in any of the tested samples.

A sorbent material based on a newly synthesized hydrazone ligand, 4-hydroxy-N'-[(E)-(2-hydroxyphenyl)methylidene]benzohydrazide was prepared by immobilizing the ligand into a silica sol-gel matrix. The capability of the sorbent material for the extraction of seven biogenic amines (BAs), i.e., tryptamine (TRY), beta-phenylethylamine (PEA), putrescine (PUT), cadaverine (CAD), histamine (HIS), tyramine (TYR), and spermidine (SPD) was studied. Under the adopted conditions, the sorbent showed good selectivity towards PUT, CAD, HIS and SPD (% extraction (%E)>96) while %E for TYR, TRY and PEA were 82.0, 78.9 and 46.4%, respectively. The sorbent could be used up to six extraction cycles for SPD, CAD and PUT and was applied to the determination of food samples ("budu", ketchup, orange juice, soy sauce) that were spiked with 20 mg L(-1) of the BAs. The extracted analytes were derivatized with dansyl chloride before the HPLC determination. With the exception of HIS and TYR in "budu" sample, reasonable recoveries were found for the other analytes in all the tested food samples.

A reversed-phase HPLC method with fluorescence detection for the determination of the aflatoxins B1, B2, G1 and G2 in 42 animal feeds, comprising corn (16), soya bean meal (8), mixed meal (13), sunflower, wheat, canola, palm kernel, copra meals (1 each) was carried out. The samples were first extracted using acetonitrile:water (9:1), and was further cleaned-up using a multifunctional column. Optimum conditions for the extraction and chromatographic separation were investigated. By adopting an isocratic chromatographic system using a mobile phase comprising acetonitrile:methanol:water (8:27:65, v/v/v), the separation of the four aflatoxins was possible within 30 min. Recoveries for aflatoxins B1, B2, G1 and G2 were 98 ± 0.7%, 95 ± 1.0%, 94 ± 3.6% and 97 ± 4.3%, respectively. The results show that eight samples (19%) were contaminated with aflatoxins, ranging from 6.5 to 101.9 ng g−1. Total aflatoxin levels in three samples exceed the legal limits of many countries of 20 ng g−1.

Three sorbent materials (A18C6-MS, DA18C6-MS and AB18C6-MS) based on the crown ether ligands, 1-aza-18-crown-6, 1,4,10,13-tetraoxa-7,16-diazacyclo octadecane and 4'-aminobenzo-18-crown-6, respectively, were prepared by the chemical immobilization of the ligand onto mesoporous silica support. The sorbents were characterized by FT-IR, scanning electron microscopy-energy dispersive X-ray microanalysis, elemental analysis and nitrogen adsorption-desorption test. The applicability of the sorbents for the extraction of biogenic amines by the batch sorption method was extensively studied and evaluated as a function of pH, biogenic amines concentration, contact time and reusability. Under the optimized conditions, all the sorbents exhibited highest selectivity toward spermidine (SPD) compared to other biogenic amines (tryptamine, putrescine, histamine and tyramine). Among the sorbents, AB18C6-MS offer the highest capacity and best selectivity towards SPD in the presence of other biogenic amines. The AB18C6-MS sorbent can be repeatedly used three times as there was no significant degradation in the extraction of the biogenic amines (%E>85). The optimized procedure was successfully applied for the separation of SPD in food samples prior to the reversed-phase high performance liquid chromatography separation.

A simple, rapid and validated capillary electrophoretic method has been developed for the separation and determination of ofloxacin and ornidazole in pharmaceutical formulations with detection at 230 nm. Optimal conditions for the quantitative separations were investigated. Analysis times shorter than 4 min were obtained using a background electrolyte solution consisting of 25 mmol/L phosphoric acid adjusted with 1 m Tris buffer to pH 8.5, with hydrodynamic injection of 5 s and 20 kV separation voltage. The validation criteria for accuracy, precision, linearity and limits of detection and quantitation were examined and discussed. An excellent linearity was obtained in concentration range 25–250 µg/mL. The detection limits for ofloxacin and ornidazole were 1.03 ± 0.11 and 1.80 ± 0.06 µg/mL, respectively. The proposed method has been applied for the analysis of ofloxacin and ornidazole both individually and in a combined dosage tablet formulation. The proposed validated method showed recoveries between 96.16 and 105.23% of the nominal contents. Copyright © 2009 John Wiley & Sons, Ltd.

Advanced Abstracts of The Seventh Libyan Diabetes and Endocrinology Conference 7-9 April 2009, Tripoli Libya

Hollow fibre liquid-phase microextraction with in situ derivatization using dansyl chloride has been successfully developed for the high-performance liquid chromatography-ultraviolet (HPLC-UV) determination of the biogenic amines (tryptamine, putrescine, cadaverine, histamine, tyramine, spermidine) in food samples. Parameters affecting the performance of the in situ derivatization process such as type of extraction solvent, temperature, extraction time, stirring speed and salt addition were studied and optimized. Under the optimized conditions (extraction solvent, dihexyl ether; acceptor phase, 0.1M HCl; extraction time, 30 min; extraction temperature, 26 degrees C; without addition of salt), enrichment factors varying from 47 to 456 were achieved. Good linearity of the analytes was obtained over a concentration range of 0.1-5 microg mL(-1) (with correlation coefficients of 0.9901-0.9974). The limits of detection and quantification based on a signal-to-noise ratio of 3-10, ranged from 0.0075 to 0.030 microg mL(-1) and 0.03 to 0.10 microg mL(-1), respectively. The relative standard deviations based on the peak areas for six replicate analysis of water spiked with 0.5 microg mL(-1) of each biogenic amine were lower than 7.5%. The method was successfully applied to shrimp sauce and tomato ketchup samples, offering an interesting alternative to liquid-liquid extraction and solid phase extraction for the analysis of biogenic amines in food samples.

A capillary zone electrophoretic method has been developed and validated for the determination of the impurity quinocide (QC) in the antimalarial drug primaquine (PQ). Different buffer additives such as native cyclodextrins and crown ethers were evaluated. Promising results were obtained when either beta-cyclodextrin (beta-CD) or 18-crown-6 ether (18C6) were used. Their separation conditions such as type of buffer and its pH, buffer additive concentration, applied voltage capillary temperature and injection time were optimized. The use of 18C6 offers slight advantages over beta-CD such as faster elution times and improved resolution. Nevertheless, migration times of less than 5 min and resolution factors (R(s)) in the range of 2-4 were obtained when both additives were used. The method was validated with respect to selectivity, linearity, limits of detection and quantitation, analytical precision (intra- and inter-day variability) and repeatability. Concentrations of 2.12 and 2.71% (w/w) of QC were found in pharmaceutical preparations of PQ from two different manufacturers. A possible mechanism for the successful separation of the isomers is also discussed.

The biogenic amines tryptamine (TRP), putrescine (PUT), histamine (HIS), tyramine (TYR) and spermidine (SPD) were determined in 62 selected food items commonly consumed in Malaysia. This include the local appetisers “budu” and “cincalok”, canned fish, salt-cured fish, meat products, fruit juice, canned vegetables/fruits and soy bean products. After the aqueous extraction, the samples were derivatised with dansyl chloride before analysing using reversed phase HPLC with UV detection. Mean levels of TRP, PUT, HIS, TYR and SPD in eight budu samples were 82.7, 38.1, 187.7, 174.7 and 5.1 mg kg −1 , respectively. The main biogenic amines found in cincalok were PUT, HIS and TYR where the mean values were 330.7, 126.1 and 448.8 mg kg −1 , respectively. With the exception of “pekasam” and “belacan”, significantly lower levels of biogenic amines were found in canned fish and salt-cured fish samples. Non detectable or low levels of biogenic amines were found in meat, fruit juice and canned vegetables/fruit samples.

A capillary zone electrophoresis (CZE) method has been developed for the determination of the antibiotic sparfloxacin in tablets. The CZE separation was performed using 75 µm×35 cm fused-silica capillary under the following conditions: 25°C; applied voltage, 12 kV; 25 mM H3PO4-NaOH running buffer (pH 8.5). The detection wavelength was 254 nm. Flumequine was used as internal standard (IS). The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision, specificity, and robustness. The calibration was linear from 10 to 60 µg mL−1 and the limit of detection and quantification were 5.38 and 9.46 µg mL−1, respectively. Recoveries ranging from 95.68%–102.4% were obtained in the determination of sparfloxacin that were spiked to placebos. Excipients in the commercial tablets and degraded products from different stress conditions did not interfere in the assay. The method was successfully applied to the determination of sparfloxacin in pharmaceutica...

A capillary zone electrophoresis (CZE) method has been developed for the determination of the antibiotic ofloxacin in tablets. The CZE separation was performed using 75 µm × 35 cm fused silica capillary under the following conditions: 25°C; applied voltage, 12 kV; 25 mM H3PO4-NaOH running buffer (pH 8.5). The detection wavelength was 254 nm. Flumequine was used as internal standard. The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision, specificity, and robustness. The calibration was linear from 5 to 50 µg mL−1 and the limit of detection and quantification were 1.24 and 4.01 µg mL−1, respectively. Recoveries ranging from 99.71–102.4% were obtained in the determination of ofloxacin that were spiked to placebos. Excipients in the commercial tablets and degraded products from different stress conditions did not interfere in the assay. The method was successfully applied to the determination of ofloxacin in pharmaceutical tablets.

A new ligand, 25,27-bis (3-(4'-biphenyl-4-hydroxy carboxylic acid) propoxy)-26,28-dihydroxy-5,11,17-tetra(tert-butyl)calix[4]arene (CBiPh), a derivative of p-tert-butylcalix[4]arene (Cax) that was functionalized at the lower rim with biphenyl carboxylic acid has been synthesized. The compound was characterized by using NMR, FT-IR, and elemental analysis. The 1 H and 13 C NMR studies indicate that this new macrocycle (CBiPh) preferably adopts a cone structure. Sorbent materials prepared by immobilizing the ligands into silica sol-gel matrix (referred to as calixarene immobilized with sorbent (Cax-SG) and CBiPh immobilized with sorbent (CBiPh-SG)) were studied for their competitive sorption characteristic of a mixture of twelve metal ions (Mg 2+ , Li + , Cd 2+ , Co 2+ , Pb 2+ , Ca 2+ , Ba 2+ , Rb + , Ag + , Cs + , Sr 2+ , and Hg 2+ ). Under the adopted conditions, both sorbents exhibited highest selectivity toward Ag + (70% for Cax-SG and 85% CBiPh-SG), followed by Hg 2+ (60% for Cax-SG and 65% CBiPh-SG) while the other metal ions were negligibly extracted (

A capillary zone electrophoretic (CZE) method has been developed for the determination of gemifloxacin and lomefloxacin in pharmaceutical tablet formulations. The CZE separation was performed using a 75 µm×35 cm fused silica capillary under the following conditions: 25°C; applied voltage, 12 kV; 25 mM H3PO4‐NaOH running buffer (pH 8.5). The detection wavelength was 254 nm. Flumequine was used as internal standard. The method was suitably validated with respect to linearity, limit of detection and quantification, accuracy, precision, specificity, and robustness. The calibration was linear from 5 to 50 µg mL−1 for gemifloxacin and 10 to 60 µg mL−1 for lomefloxacin, and the limit of detection and quantification were 2.93, 4.91 µg mL−1, and 3.87, 8.93 for gemifloxacin and lomefloxacin, respectively. Recoveries ranging from 94.4–108.6% were obtained for both drugs. The method was successfully applied to the determination of gemifloxacin and lomefloxacin in pharmaceutical tablets. Excipients present in...

A capillary electrophoretic method for the separation of the enantiomers of ofloxacin using carboxymethyl‐β‐cyclodextrin (CM‐β‐CD) as chiral selector is described. The effect of the type of cyclodextrin and its concentration, buffer concentration, and its pH, as well as instrumental parameters, such as applied voltage and temperature were systematically studied. The highest resolution of ofloxacin enantiomers obtained was around 2.8. This was achieved using Tris‐citrate buffer (pH 4.5) that contained 3 mg mL−1 CM‐β‐CD and using UV detection (254 nm), applied voltage (12 kV), and capillary temperature of 25°C. Acceptable validation criteria for selectivity, precision, linearity, limit of detection, and quantitation were also included. Recoveries between 98.3–103.4% were obtained when the method was used to determine the enantiomers of ofloxacin that were spiked to placebos. The proposed method is fast, sensitive, inexpensive, and its usefulness was demonstrated for the analysis of five pharmaceuti...

A HPLC with gradient elution method for the determination of the synthetic phenolic antioxidants (SPAs) propyl gallate (PG), tertiary butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) in food items is described. A C18 column served as the stationary phase; the gradient elution was formed by acetonitrile and water:acetic acid (1%). The UV detector was set at 280 nm. Under the recommended conditions, separation of the four SPAs was achieved in less than 8 min. Analytical characteristics of the HPLC method such as limit of detection, linear range, and reproducibility were evaluated. Extraction parameters were optimized for the recoveries of the SPAs in different types of food items (cooking oil, margarine and butter, and cheese). Before the HPLC separation, the SPAs were extracted with methanol/acetonitrile (1:1, v/v) and were subjected to vortex/ultrasonic treatment. The extracts were next kept in a freezer (∼2 h) to precipitate co-extracted components. Recoveries of the SPAs when spiked to cooking oil, margarine, butter and cheese at 50 and 200 mg l−1 were in the ranges 93.3–108.3% for PG, 85.3–108.3% for TBHQ, 96.7–101.2% for BHA and 73.9–94.6% for BHT. The method was applied to the determination of SPAs in 38 food items (16 cooking oils, ten margarine, six butter and six cheese samples). The levels of SPAs in positive samples are all below the legal limits of Malaysia.

Flow injection (FI) non-aqueous titrimetric methods for the determination of free fatty acids (FFA) in palm oil samples are described. Single-line and two-line FI manifolds using phenolphthalein (PHP) and bromothymol blue (BTB) as indicators were developed. The method is based on the monitoring of the changes of absorbance of the indicators used from basic–acidic–basic form (pink–colourless–pink for PHP, blue–yellow–blue for BTB) as a result of the neutralization of KOH that was used as carrier stream by the injected FFA sample. FI parameters such as carrier and reagent concentration, flow-rate, length of reaction coil, size of mixing chamber and injected volume were optimized. The single-line manifold with PHT as indicator is recommended for the determination of samples with acidity degree (a.d.) higher than 0.4, but the oil samples need to be diluted with 2-propanol before their injection. For lower acidities (a.d. −1 for single-line and two-line manifolds, respectively, were achieved. Fifty different samples of palm oils were tested using the appropriate FIA manifolds, and results were compared with the standard PORIM procedure which involves manual titration. Good correlations between the two methods were obtained ( r 2 , at least 0.92) UV–VIS absorption spectra indicate that the absorption of these oil samples were minimum at the detection wavelengths (562 nm for PHP and 627 for BTB), indicating that the method is negligibly interfered from the background colour of the samples.