Journal of Chemistry http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Laser-Induced Breakdown Spectroscopy in Africa Wed, 04 Mar 2015 14:22:58 +0000 http://www.hindawi.com/journals/jchem/2015/648385/ Laser-induced breakdown spectroscopy (LIBS), known also as laser-induced plasma spectroscopy (LIPS), is a well-known spectrochemical elemental analysis technique. The field of LIBS has been rapidly matured as a consequence of growing interest in real-time analysis across a broad spectrum of applied sciences and recent development of commercial LIBS analytical systems. In this brief review, we introduce the contributions of the research groups in the African continent in the field of the fundamentals and applications of LIBS. As it will be shown, the fast development of LIBS in Africa during the last decade was mainly due to the broad environmental, industrial, archaeological, and biomedical applications of this technique. M. A. Kasem and M. A. Harith Copyright © 2015 M. A. Kasem and M. A. Harith. All rights reserved. Cometabolism of Fluoroanilines in the Presence of 4-Fluoroaniline by Ralstonia sp. FD-1 Mon, 02 Mar 2015 10:13:32 +0000 http://www.hindawi.com/journals/jchem/2015/206150/ A strain of Ralstonia sp. FD-1 capable of using 4-fluoroaniline (4-FA) as the sole carbon and nitrogen source was investigated for its ability to utilize 4-FA isomers (2-FA, 3-FA) and homologs (2,4-DFA, 3,4-DFA, and 2,3,4-TFA). Both 4-FA and 3-FA could be mineralized as the sole carbon and nitrogen source by FD-1. 2-FA, 2,4-DFA, 3,4-DFA, and 2,3,4-TFA could not be degraded by FD-1, respectively, and were selected as secondary substrates for cometabolism with 500 mg/L 4-FA as growth substrate. Bacterial growth (OD600), F− concentrations, and fluoroanilines contents were measured to determinate the degradation ability of 4-FA isomers and homologs by FD-1. FD-1 growth was inhibited by 2,4-DFA, 3,4-DFA, and 2,3,4-TFA at higher concentrations (400 mg/L), except for 2-FA. Complete fluoroanilines degradation was achieved while incomplete defluorination was characterized by the stoichiometric fluoride release indicating partial degradation but not total mineralization. When fluoroaniline was supplied to the resting cells of strain FD-1, a relatively effective removal was showed. Strain FD-1 had broadened application prospect of toxicity and low nutrition fluoroanilines wastewater. Wenling Cao, Erxi Song, Dongsheng Shen, and Meizhen Wang Copyright © 2015 Wenling Cao et al. All rights reserved. Biocompatible SiO2 in the Fabrication of Stimuli-Responsive Hybrid Composites and Their Application Potential Sun, 01 Mar 2015 12:30:48 +0000 http://www.hindawi.com/journals/jchem/2015/846328/ Organic/inorganic hybrid composite materials have been extensively studied as they combine the properties of inorganic material and organic polymer. Among the inorganic material biocompatible silica (SiO2) is an interesting candidate for application in biotechnology because such material is wide spread in nature as well as in medicine. During the last few decades, stimuli-responsive polymers are drawing much attention from the researchers for application versatility such as target-specific delivery of drug and corrosion inhibitors. Considering the biocompatibility and many such important properties as high cargo loading capacity, long blood circulation lifetime, enhanced permeability and retention, mechanical strength, and easy processability, combination of SiO2 particles with stimuli-responsive polymers is gaining attention over the last decade. This review article will report the progress made towards the development and application of stimuli-responsive hybrid composites based on SiO2. Hasan Ahmad Copyright © 2015 Hasan Ahmad. All rights reserved. Liquid-Phase Polymer-Based Retention: Theory, Modeling, and Application for the Removal of Pollutant Inorganic Ions Sun, 01 Mar 2015 08:38:28 +0000 http://www.hindawi.com/journals/jchem/2015/965624/ The aim of this work is to give the theoretical background of liquid-phase polymer-based retention (LPR) technique, provide a complete model of separation process, and evaluate its application for the removal of pollutant inorganic ions (PIIs) from aqueous solution. Thus, fundaments of LPR modeling by washing method from the ion distribution in active and passive zones are specified and its application was evaluated for cadmium removal using poly(sodium styrene sulfonate) as water-soluble polymer (WSP). LPR simulations were performed using a semiempirical description from data of concentration, filtration factorm, and retention coefficients. It is concluded that semiempirical simulation of PII retention by WSP can be performed from a small amount of experimental data using the described modeling. In addition, new approximations associated with molecular structure of polymer should be performed and linked to parameters of LPR experiments. Manuel Palencia Copyright © 2015 Manuel Palencia. All rights reserved. Impact of Production Location, Production System, and Variety on the Volatile Organic Compounds Fingerprints and Sensory Characteristics of Tomatoes Sun, 01 Mar 2015 06:43:28 +0000 http://www.hindawi.com/journals/jchem/2015/981549/ Consumers have more and more interest in where and how their foods are produced. However, it is often challenging to discriminate products from different production locations and systems. The objective of this study was to examine fingerprinting of volatile organic compounds (VOCs) as an approach for characterization and discrimination of tomatoes by their production location, production system, and variety using Proton Transfer Reaction Mass Spectrometry combined with multivariate statistics. Sensory analysis was complementing the VOC analyses. The study was part of the EU CORE Organic II project AuthenticFood. Tomato sample batches cultivated in two locations in Italy, according to the organic and conventional production system, comprising two varieties, and produced in two consecutive years were examined. Both factors production location and production system impacted considerably the VOC fingerprints, but compared to these two factors, minor differences were observed between the two varieties of tomatoes studied. VOC data were successfully used to predict the origin and production system for this sample set. Sensory data also primarily indicated the differences between origin and production systems, and several sensory attributes could be predicted from the VOC fingerprints. Therefore, VOC fingerprints reflect production conditions and are promising for substantiation and authentication of special tomato traits. Mirthe Muilwijk, Samuel Heenan, Alex Koot, and Saskia M. van Ruth Copyright © 2015 Mirthe Muilwijk et al. All rights reserved. Reaction of Nitrilimines with Pyruvaldehyde Hydrazones: Synthesis and Antimicrobial Evaluation of Some New 1,2,4-Triazole Derivatives Sat, 28 Feb 2015 10:47:07 +0000 http://www.hindawi.com/journals/jchem/2015/593738/ A new series of 1,3,4,5,5-pentasubstituted-1,2,4-triazoles (4a–j, 6a–j) have been synthesized by the 1,3-dipolar cycloaddition of suitable nitrilimines 2 to pyruvaldehyde (2-oxopropanal) hydrazones having (COPh, COOMe, COOEt, Me/Me, and Me/Ph) groups 3 and 5. Both analytical and spectroscopical data of all the synthesized compounds are in full agreement with the proposed structures. The microbial features of the synthesized compounds were studied by a known method. Hany M. Dalloul Copyright © 2015 Hany M. Dalloul. All rights reserved. Effect of PAN Oxidation on the Electrochemical Lithium Insertion/Deinsertion Behavior of Resultant Carbons Thu, 26 Feb 2015 18:44:59 +0000 http://www.hindawi.com/journals/jchem/2015/370906/ The effect of polyacrylonitrile (PAN) oxidation on the properties and electrochemical lithium insertion/deinsertion behavior of carbons produced in the temperature range of 1000–1150°C has been assessed. Air-treatment at 220 and 240°C modifies essentially the carbonization behavior of polymer leading to materials with developed microporosity and enhanced oxygen content in contrast to practically nonporous pristine PAN-based carbon. The extent of the modification increases with the oxidation depth and decreases with HTT. Galvanostatic charge/discharge reveals typical hard carbons characteristics of all the materials. PAN-based carbon heat-treated at 1050°C represents most promising anodic performance. It gives reversible capacity () near 420 mAh g−1 with a reasonable coulombic efficiency during cycling of ~99% and a moderate low voltage capacity of 100 mAh g−1. Extensive oxidation enhances overall 1st discharge cycle capacity to 870 mAh g−1 and to 560 mAh g−1; however, large irreversible capacity () and poor cycleability are serious drawbacks of all carbons from oxidized PAN. Pyrolytic carbon coating using methane CVD at 830°C is effective in suppressing by about 30% but the cycleability remains nonacceptable. Aleksandra Piotrowska, Krzysztof Kierzek, and Jacek Machnikowski Copyright © 2015 Aleksandra Piotrowska et al. All rights reserved. Oyster and Pyramidella Shells as Heterogeneous Catalysts for the Microwave-Assisted Biodiesel Production from Jatropha curcas Oil Thu, 26 Feb 2015 12:26:32 +0000 http://www.hindawi.com/journals/jchem/2015/578625/ Microwave-assisted biodiesel production via transesterification of Jatropha curcas oil with methanol using solid oxide catalyst derived from waste shells of oyster and Pyramidella was studied. The shells were calcined at 900°C for 2 h and calcium oxide (CaO) catalyst characterizations were carried out by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope (SEM), and the Brunauer-Emmett-Teller (BET) surface area measurements. The effects of reaction variables such as reaction time, microwave power, methanol/oil molar ratio, and catalyst loading on the yield of biodiesel were investigated. Reusability of waste shell catalyst was also examined. The results indicated that the economic and environmentally friendly catalysts derived from oyster and Pyramidella shells showed good reusability and had high potential to be used as biodiesel production catalysts under microwave-assisted transesterification of Jatropha curcas oil with methanol. Achanai Buasri, Tidarat Rattanapan, Chalida Boonrin, Chosita Wechayan, and Vorrada Loryuenyong Copyright © 2015 Achanai Buasri et al. All rights reserved. Antioxidant and Sensorial Properties of Polyfloral Honey with Dried Apricots after One Year of Storage Thu, 26 Feb 2015 11:25:17 +0000 http://www.hindawi.com/journals/jchem/2015/858049/ Total phenol (TPh) and flavonoid (TFd) contents, antioxidant and sensorial properties of polyfloral (PH), and polyfloral honey after one year of storage (PHs) with dried apricots (20, 30, and 40%) were evaluated. In comparison to honey, TPh increased 1.86 times for PH40. After storage time, TPh of PH40s increased slightly lower (1.77 times), compared to PHs. TFd slightly increased, approximately 3.23-fold, from PH to PH40, while PHs showed increase of 5.15-fold for PH40s. Antioxidant activity increased with increasing concentration of apricots in honey. varied from 3.36 for PH to 2.29 mg/mL for PH40 and from 3.48 for PHs to 2.68 mg/mL for PH40s; ranged from 30.60 for PH to 14.95 mg/mL for PH40 and from 31.22 for PHs to 17.43 mg/mL for PH40s; RP0.5 ranged from 66.37 for PH to 31.83 mg/mL for PH40 and from 67.99 for PHs to 35.03 mg/mL for PH40s. Statistical analysis suggested that TPh and TFd were associated with antioxidant activity and colour. Sensory parameters, before and after storage, indicated very good sensory qualities. Phenolic composition, antioxidant capacity, and sensory properties were promoted after addition of dried apricots and these parameters stayed improved, since antioxidant compounds present in dried apricots aided in maintenance of honey properties along one year of storage. Jelena Vulić, Jasna Čanadanović-Brunet, Gordana Ćetković, Sonja Djilas, and Vesna Tumbas Šaponjac Copyright © 2015 Jelena Vulić et al. All rights reserved. Effect of Organic Inhibitors on Chloride Corrosion of Steel Rebars in Alkaline Pore Solution Thu, 26 Feb 2015 10:08:30 +0000 http://www.hindawi.com/journals/jchem/2015/521507/ The inhibition properties of aspartic and lactic acid salts are compared with nitrite ions with regard to their effect on critical chloride concentration. The tests were carried out on carbon steel specimens in simulated pore solutions with initial pH in the range of 12.6 to 13.8. The critical chloride concentrations were estimated through multiple specimen potentiostatic tests at potentials in the usual range for passive rebar in noncarbonated concrete structures. During tests, chloride ions were progressively added until all specimens showed localized attack, obtaining cumulative distribution curves reporting the fraction of corroded specimens as a function of chloride concentration. The presence of the organic inhibitors on the passivity film was detected by IR spectra. The results confirm that 0.1 M aspartate exhibits an inhibiting effect comparable with nitrite ions of the same concentration. Calcium lactate does not increase critical chloride concentration; however it appears to promote the formation of a massive scale, reducing the corrosion propagation. Marina Cabrini, Francesca Fontana, Sergio Lorenzi, Tommaso Pastore, and Simone Pellegrini Copyright © 2015 Marina Cabrini et al. All rights reserved. Phragmites karka as a Biosorbent for the Removal of Mercury Metal Ions from Aqueous Solution: Effect of Modification Thu, 26 Feb 2015 08:21:34 +0000 http://www.hindawi.com/journals/jchem/2015/293054/ Batch scale studies for the adsorption potential of novel biosorbent Phragmites karka (Trin), in its natural and treated forms, were performed for removal of mercury ions from aqueous solution. The study was carried out at different parameters to obtain optimum conditions of pH, biosorbent dose, agitation speed, time of contact, temperature, and initial metal ion concentration. To analyze the suitability of the process and maximum amount of metal uptake, Dubinin-Radushkevich (D-R) model, Freundlich isotherm, and Langmuir isotherm were applied. The values of for natural and treated biosorbents were found at 1.79 and 2.27 mg/g, respectively. The optimum values of contact time and agitation speed were found at 50 min and 150 rpm for natural biosorbent whereas 40 min and 100 rpm for treated biosorbent, respectively. The optimum biosorption capacities were observed at pH 4 and temperature 313 K for both natural P. karka and treated P. karka. values indicate that comparatively treated P. karka was more feasible for mercury adsorption compared to natural P. karka. Both pseudo-first-order and pseudo-second-order kinetic models were applied and it was found that data fit best to the pseudo-second-order kinetic model. Thermodynamic studies indicate that adsorption process was spontaneous, feasible, and endothermic. Muhammad Hamid Raza, Aqsa Sadiq, Umar Farooq, Makshoof Athar, Tajamal Hussain, Adnan Mujahid, and Muhammad Salman Copyright © 2015 Muhammad Hamid Raza et al. All rights reserved. Phase Behavior and Heat Capacity of {DPnP + Water} Mixtures at the Temperature Range of 273.15–338.15 K Wed, 25 Feb 2015 16:09:22 +0000 http://www.hindawi.com/journals/jchem/2015/932819/ The differential scanning calorimetry method (DSC) was used to examine the miscibility in the dipropylene glycol propyl ether (DPnP) + water system. Based on recorded curves of differential heat flow on temperature, HF , the range (composition, temperature) of the occurrence of miscibility gap, the values of lower critical solution temperature (LCST), and critical concentration were determined. On the basis of the experimentally determined specific heat capacity data the partial molar heat capacities () of DPnP in the mixtures with water were calculated. Analyzing changes in the course of function, the boundary of transition from a homogeneous solution was determined, in which the monomers of amphiphile dominate, to the region, in which aggregates of the cluster type appear. Mariola Tkaczyk, Henryk Piekarski, and Paweł Góralski Copyright © 2015 Mariola Tkaczyk et al. All rights reserved. Simultaneous HPLC Determination of Chlordiazepoxide and Mebeverine HCl in the Presence of Their Degradation Products and Impurities Wed, 25 Feb 2015 10:11:44 +0000 http://www.hindawi.com/journals/jchem/2015/293719/ A simple, rapid, and sensitive RP-HPLC method was developed and validated for the simultaneous determination of chlordiazepoxide (CDO) and mebeverine HCl (MBV) in the presence of CDO impurity (2-amino-5-chlorobenzophenone, ACB) and MBV degradation product (veratric acid, VER). Separation was achieved within 9 min on a BDS Hypersil phenyl column (4.5 mm × 250 mm, 5 µm particle size) using a mobile phase consisting of acetonitrile: 0.1 M potassium dihydrogen phosphate: triethylamine (35 : 65 : 0.2, v/v/v) in an isocratic mode at a flow rate of 1 mL/min. The pH of the mobile phase was adjusted to 4.5 with orthophosphoric acid and UV detection was set at 260 nm. A complete validation procedure was conducted. The proposed method exhibited excellent linearity over the concentration ranges of 1.0–100.0, 10.0–200.0, 2.0–40.0, and 2.0–40.0 µg/mL for CDO, MBV, VER, and ACB, respectively. The proposed method was applied for the simultaneous determination of CDO and MBV in their coformulated tablets with mean percentage recoveries of 99.75 ± 0.62 and 98.61 ± 0.38, respectively. The results of the proposed method were favorably compared with those of a comparison HPLC method using Student t-test and the variance ratio F-test. The chemical structure of MBV degradation product was ascertained by mass spectrometry and IR studies. Rania N. El-Shaheny and Fathalla F. Belal Copyright © 2015 Rania N. El-Shaheny and Fathalla F. Belal. All rights reserved. A Microwave-Based Chemical Factory in the Lab: From Milligram to Multigram Preparations Wed, 25 Feb 2015 07:10:25 +0000 http://www.hindawi.com/journals/jchem/2015/879531/ Microwave technology is changing the way we design and optimize synthetic protocols and their scaling up to multigram production levels. The latest generation of dedicated microwave reactors enables operators to quickly screen reaction conditions by means of parallel tests and select the best catalyst, solvent, and conditions. Pilot scale synthetic procedures require flow-through conditions in microwave flow reactors which can be obtained by adapting classic batch protocols. Microwave-assisted chemical processes play a pivotal role in the design of sustainable multigram preparations which address the double requirement of process intensification and competitive production costs. Although most researchers are likely to be acquainted with the great potential of dielectric heating, the advantages and disadvantages of a particular device or the conditions needed to maximize efficiency and functionality are often overlooked. The double aims of the present review are to provide a panoramic snapshot of commercially available lab microwave reactors and their features as well as highlighting a few selected applications of microwave chemistry of particular relevance. Laura Rinaldi, Diego Carnaroglio, Laura Rotolo, and Giancarlo Cravotto Copyright © 2015 Laura Rinaldi et al. All rights reserved. Synthesis of Novel Fluorescent Sensors Based on Naphthalimide Fluorophores for the Highly Selective Hg2+-Sensing Wed, 25 Feb 2015 06:48:58 +0000 http://www.hindawi.com/journals/jchem/2015/165295/ With an aim to develop the new sensors for optical detection of Hg2+ ions, two novel fluorometric sensors were designed and successfully prepared using 2-(3-(2-aminoethylsulfanyl)propylsulfanyl)ethanamine and one or two N-methylnaphthalimide moieties (1 and 2). Sensor 1 was obtained via N-alkylation, N-imidation and a one-pot nucleophilic aromatic substitution, and N-formylation of the amine, while sensor 2 was prepared via N-alkylation, N-imidation, and nucleophilic aromatic substitution. The characterization, including 1H NMR, 13C NMR, and mass spectrometry, was then performed for 1 and 2. The Hg2+-binding behaviors of the sensors were investigated in terms of sensitivity and selectivity by fluorescence spectroscopy. Sensor 1 especially provided the reversible and highly Hg2+-selective ON-OFF fluorescence behavior by discriminating various interfering ions such as Pb2+, Co2+, Cd2+, Mn2+, Fe2+, K+, Na+, and in particular Cu2+ and Ag+ with a detection limit of 22 ppb toward Hg2+ ions. Yordkhuan Tachapermpon, Pornthip Piyanuch, Narupon Prapawattanapol, Kanjarat Sukrat, Kullatat Suwatpipat, and Nantanit Wanichacheva Copyright © 2015 Yordkhuan Tachapermpon et al. All rights reserved. Synthesis, Crystal Structure, and DFT Calculations of 1,3-Diisobutyl Thiourea Tue, 24 Feb 2015 14:26:34 +0000 http://www.hindawi.com/journals/jchem/2015/913435/ 1,3-Diisobutyl thiourea was synthesized and characterized by single crystal X-ray diffraction. It gives a monoclinic (α = γ = 90 and β  ≠ 90) structure with the space group P21/c. The unit cell dimensions are a = 11.5131 (4) Å, b = 9.2355 (3) Å, c = 11.3093 (5) Å, α = 90°, β = 99.569° (2), γ = 90°, V = 1185.78 (8) Å3, and Z = 4. The crystal packing is stabilized by intermolecular (N–H⋯S) hydrogen bonding in the molecules. The optimized geometry and Mullikan's charges of the said molecule calculated with the help of DFT using B3LYP-6-311G model support the crystal structure. Ataf A. Altaf, Adnan Shahzad, Zarif Gul, Sher A. Khan, Amin Badshah, Muhammad N. Tahir, Zafar I. Zafar, and Ezzat Khan Copyright © 2015 Ataf A. Altaf et al. All rights reserved. Doxycycline Degradation by the Oxidative Fenton Process Tue, 24 Feb 2015 13:59:05 +0000 http://www.hindawi.com/journals/jchem/2015/492030/ Doxycycline is a broad-spectrum tetracycline occurring in domestic, industrial, and rural effluents, whose main drawback is the increasing emergence of resistant bacteria. This antibiotic could be degraded by the so-called Fenton process, consisting in the oxidation of organic pollutants by oxygen peroxide (H2O2) in the presence of Fe2+. Experiments were performed according to an experimental Rotational Central Composite Design to investigate the influence of temperature (0–40.0°C), H2O2 concentration (100–900 mg/L), and Fe2+ concentration (5–120 mg/L) on residual doxycycline and total organic carbon concentrations. Whereas the final residual doxycycline concentration ranged from 0 to 55.8 mg/L, the oxidation process proved unable to reduce the total organic carbon by more than 30%. The best operating conditions were concentrations of H2O2 and Fe2+ of 611 and 25 mg/L, respectively, and temperature of 35.0°C, but the analysis of variance revealed that only the first variable exerted a statistically significant effect on the residual doxycycline concentration. These results suggest possible application of this process in the treatment of doxycycline-containing effluents and may be used as starting basis to treat tetracycline-contaminated effluents. Alexandre A. Borghi, Milena F. Silva, Saleh Al Arni, Attilio Converti, and Mauri S. A. Palma Copyright © 2015 Alexandre A. Borghi et al. All rights reserved. Unusual Chair-Like G-Quadruplex Structures: Heterochiral TBA Analogues Containing Inversion of Polarity Sites Tue, 24 Feb 2015 09:13:02 +0000 http://www.hindawi.com/journals/jchem/2015/473051/ Heterochiral oligodeoxynucleotides based on the thrombin binding aptamer sequence, namely, 5′gg3′-3′TT5′-5′ggtgtgg3′-3′TT5′-5′gg3′ (H1), 5′gg3′-3′TT5′-5′gg3′-3′TGT5′-5′gg3′-3′TT5′-5′gg3′ (H2), and 5′gGTTGgtgtgGTTGg3′ (H3), where lower case letters indicate L-residues, have been investigated in their ability to fold in G-quadruplex structures through a combination of gel electrophoresis, circular dichroism, and UV spectroscopy techniques. In H1 and H2 inversions of polarity sites have been introduced to control the strand direction in the loop regions. Collected data suggest that all modified sequences are able to fold in chair-like G-quadruplexes mimicking the original TBA structure. Antonella Virgilio, Luciano Mayol, Michela Varra, Aldo Galeone, and Veronica Esposito Copyright © 2015 Antonella Virgilio et al. All rights reserved. Wettability Studies Using Zeta Potential Measurements Tue, 24 Feb 2015 08:25:16 +0000 http://www.hindawi.com/journals/jchem/2015/743179/ Wettability studies have been carried out on reservoir rocks using different techniques such as the Amott-Harvey method, the USBM method, and the contact angle method, all with limitations. In this study, the wettability is studied by discussing the surface charge using zeta potential measurements. The study relies on the finding that carbonated reservoir rocks, consisting of CaCO3 mainly, are positively charged and their surface has the potential to adsorb significant quantities of anions. Moreover, heavy fractions such as asphaltenes are reported to remain afloat depending on dispersive forces present in the oil and its various fractions. Experiments are carried out on aqueous limestone suspension with the addition of crude oil. The experiment is repeated with the use of polymeric inhibitors, A and B. The zeta potential is found to alter depending on the sequence of polymeric inhibitor in oil/water addition. The inhibitor is found to adsorb on the limestone surface, with a net negative charge, causing repulsion between crude oil and the inhibitor and, hence, preventing the deposition of heavy fractions and particularly asphaltenes. This study gives a comprehensive insight on the mechanism of polymeric inhibitor interaction with the surface and the effect of wettability on its performance. Ghada Bassioni and Syed Taha Taqvi Copyright © 2015 Ghada Bassioni and Syed Taha Taqvi. All rights reserved. Influence of Elicitation and Germination Conditions on Biological Activity of Wheat Sprouts Mon, 23 Feb 2015 13:47:13 +0000 http://www.hindawi.com/journals/jchem/2015/649709/ The influence of elicitation, time, and temperature of germination on the biological activity of wheat sprouts was studied. The total phenolics content (TPC), antioxidant activity (AA), and microbiological purity of seeds of three wheat cultivars elicited with Saccharomyces cerevisiae (Y) and Salix daphnoides bark extracts (W) and their mixture (1 : 1) germinated in different conditions were studied. The increase of germination time caused an increase the TPC and AA for all tested wheat cultivars. Germination temperature also influenced these parameters. Generally the highest values in TPC were obtained for sprouts germinated at 20°C. This tendency was found for all tested wheat cultivars. The highest values of TPC and AA were obtained after elicitation by S. daphnoides bark extract. The results of microbiological examination showed that generally for seeds germinated at lower temperature (15°C and 20°C) and during 2 and 4 days the molds were not detected and the levels of aerobic bacteria did not exceed the usually accepted limits. Taking into account both biological activity and microbiological purity of samples the best quality sprouts were in the most cases obtained for wheat germinated during four days at 20°C and elicited by W. Dariusz Dziki, Urszula Gawlik-Dziki, Monika Kordowska-Wiater, and Monika Domań-Pytka Copyright © 2015 Dariusz Dziki et al. All rights reserved. Benefits and Limitations of Lab-on-a-Chip Method over Reversed-Phase High-Performance Liquid Chromatography Method in Gluten Proteins Evaluation Mon, 23 Feb 2015 12:31:29 +0000 http://www.hindawi.com/journals/jchem/2015/430328/ RP-HPLC (reversed-phase high-performance liquid chromatography) is widely used to determine the amounts of the different gluten protein types. However, this method is time-consuming, especially at early stages of wheat breeding, when large number of samples needs to be analyzed. On the other hand, LoaC (Lab-on-a-Chip) technique has the potential for a fast, reliable, and automatable analysis of proteins. In the present study, benefits and limitations of Lab-on-a-Chip method over RP-HPLC method in gluten proteins evaluation were explored in order to determine in which way LoaC method should be improved in order to make its results more compliant with the results of RP-HPLC method. Strong correlation () was found between numbers of HMW glutenin peaks determined by LoaC and RP-HPLC methods. Significant correlations () were obtained between percentages of HMW and LMW glutenin subunits calculated with regard to total HMW + LMW area. Even more significant correlation () was found when percentages of individual HMW areas were calculated with regard to total HMW. RP-HPLC method showed superiority in determination of gliadins since larger number and better resolution of gliadin peaks were obtained by this method. Dragan Živančev, Daniela Horvat, Aleksandra Torbica, Miona Belović, Gordana Šimić, Damir Magdić, and Nevena Đukić Copyright © 2015 Dragan Živančev et al. All rights reserved. Xanthine Oxidase: Isolation, Assays of Activity, and Inhibition Mon, 23 Feb 2015 07:57:12 +0000 http://www.hindawi.com/journals/jchem/2015/294858/ Xanthine oxidase (XO) is an important enzyme catalyzing the hydroxylation of hypoxanthine to xanthine and xanthine to uric acid which is excreted by kidneys. Excessive production and/or inadequate excretion of uric acid results in hyperuricemia. This paper presents a detailed review of methods of isolation, determination of xanthine oxidase activity, and the effect of plant extracts and their constituents on it. Determining the content and activities of XO can be used for diagnostic purposes. Testing inhibition of XO is important for detection of potentially effective compounds or extracts that can be used to treat diseases that are caused by increased activity of XO. In vitro bioassays are used to examine test material for XO inhibition, as inhibitors of XO may be potentially useful for the treatment of gout or other XO induced diseases. Several authors reported on the XO inhibitory potential of traditionally used medicinal plants. Danijela A. Kostić, Danica S. Dimitrijević, Gordana S. Stojanović, Ivan R. Palić, Aleksandra S. Đorđević, and Jovana D. Ickovski Copyright © 2015 Danijela A. Kostić et al. All rights reserved. Evaluation of Ethnopharmacological and Antioxidant Potential of Zanthoxylum armatum DC. Sun, 22 Feb 2015 12:14:30 +0000 http://www.hindawi.com/journals/jchem/2015/925654/ Zanthoxylum armatum DC. (syn. Z. alatum Roxb.) is an important medicinal plant commonly called Timur or Indian prickly ash. The ethnopharmacological study of Z. armatum revealed the use of different plant parts for curing various ailments including cholera, chest infection, fever, indigestion, stomach disorders, gas problems, piles, toothache, gum problems, dyspepsia, as carminative, antipyretic, aromatic, tonic, and stomachic. Keeping in view the medicinal potential of the plant, the antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, reducing power, and phosphomolybdate assay using different concentrations (7.81 μg/mL–250 μg/mL). Ascorbic acid was taken as standard. The results indicated that the free radical scavenging activity ranged from 40.12% to 78.39%, and the reductive potential ranged from 0.265 nm to 1.411 nm while the total antioxidant activity ranged from 0.124 nm to 0.183 nm. The antioxidant potential evaluated by three assays increased in a concentration dependent manner and ascorbic acid showed better antioxidant activity than leaf extract. Results obtained through different tests confirmed redox protective activities of Zanthoxylum armatum. Further in vitro and in vivo research should be performed, so this plant can be further utilized in drug development. Rabia Kanwal, Muhammad Arshad, Yamin Bibi, Saira Asif, and Sunbal Khalil Chaudhari Copyright © 2015 Rabia Kanwal et al. All rights reserved. Thermal and Mechanical Properties of Biodegradable Star-Shaped/Linear Polylactide Stereocomplexes Sun, 22 Feb 2015 06:43:41 +0000 http://www.hindawi.com/journals/jchem/2015/206123/ The 6-arm star-shaped poly(L-lactide) (6PLL)/linear poly(D-lactide) (1PDL) stereocomplex films were prepared by the solvent casting method. The influences of the 6PLL/1PDL blend ratios (75/25, 50/50, and 25/75 w/w) and 1PDL molecular weights (15,000, 30,000, and 60,000 g/mol) on the thermal and mechanical properties of the stereocomplex films were investigated. The 6PLL and 1PDLs had a single melting temperature () of homocrystallites at 174°C and 167°C, respectively. The 6PLL/1PDL blends had two s: a lower of homocrystallites (160–173°C) and a higher of stereocomplex crystallites (219–228°C). The stereocomplex crystallinity and mechanical properties of the 6PLL/1PDL blend films were higher than those of 6PLL and 1PDL and were the highest in the 50/50 (w/w) blend ratio. However, the stereocomplex crystallinity of the 50/50 (w/w) 6PLL/1PDL blend films decreased and the mechanical properties increased as the molecular weight of 1PDL increased. Onanong Cheerarot and Yodthong Baimark Copyright © 2015 Onanong Cheerarot and Yodthong Baimark. All rights reserved. Impact of Dietary α-Lipoic Acid on Antioxidant Potential of Broiler Thigh Meat Thu, 19 Feb 2015 18:20:11 +0000 http://www.hindawi.com/journals/jchem/2015/406894/ The lipid oxidation depressed the meat quality and can be triggered during industrial processing. The current study was designed to assess the antioxidant activity of thigh meat and meat products enriched with natural antioxidants (α-lipoic acid and α-tocopherol acetate). Broilers (21 days) were fed on feed supplemented with varying α-lipoic acid and constant concentration of α-tocopherol acetate for 3 weeks. Birds were slaughtered at the age of 42 days and meat samples were collected and stored for further analysis and product preparation. TPC and DPPH value indicated that meat of broilers receiving 100 mg of α-lipoic acid with 200 mg of α-tocopherol acetate/kg of feed possessed the highest antioxidant activity. TBARS and peroxides values were found to be lower for meat of broilers fed on different levels of α-lipoic acid. The antioxidants (lipoic acid and tocopherol) enrichment in meat helps to reduce PUFAs. A similar lipid stability trend was observed in nuggets prepared from broiler thigh meat and maximum sensory evaluation scores for nuggets prepared from thigh meat of broilers having the highest dose of lipoic acid. The lipoic acid supplementation in feed enhances the antioxidant capacity of thigh meat and meat products. Muhammad Issa Khan, Komal Shehzad, Muhammad Sajid Arshad, Amna Sahar, Muhammad Asim Shabbir, and Muhammad Saeed Copyright © 2015 Muhammad Issa Khan et al. All rights reserved. Preparation and Photocatalytic Properties of TiO2-Al2O3 Composite Loaded Catalysts Thu, 19 Feb 2015 18:02:15 +0000 http://www.hindawi.com/journals/jchem/2015/806568/ This paper presents an experimental approach to study catalytic effects of Fe3+ modified nanometer titanium dioxide (TiO2) loaded on aluminium oxide (Al2O3). Sol-gel method was used to prepare modified TiO2 loaded on carrier. Purification tests were conducted in a self-developed instrument to study catalytic effects of TiO2 loaded on Al2O3 with different contents through degradation rate. The modification mechanism was studied by scanning electron microscope (SEM). Results showed that loading on Al2O3 improved photocatalytic effect of TiO2 modified with Fe3+. The best photocatalytic effect was achieved under catalytic action of Al2O3 loaded with 10% TiO2 composite; the degradation rates were 6.9%, 13.8%, 21.4%, and 49.2%, respectively, 0.7%, 3.9%, 1.3%, and 15.1% larger than unloaded TiO2. SEM results of four catalysts showed that nanometer TiO2 was coated in form of grain on the surface of Al2O3. The optimal loading content was 10% at which the nanometer TiO2 grains were coated on the surface of Al2O3 uniformly. Jianzhong Pei, Weisi Ma, Rui Li, Yanwei Li, and Hongzhao Du Copyright © 2015 Jianzhong Pei et al. All rights reserved. Determination of Volatile Organic Compounds in Selected Strains of Cyanobacteria Thu, 19 Feb 2015 11:55:12 +0000 http://www.hindawi.com/journals/jchem/2015/969542/ Microalgal biomass can be used in creating various functional food and feed products, but certain species of microalgae and cyanobacteria are known to produce various compounds causing off-flavour. In this work, we investigated selected cyanobacterial strains of Spirulina, Anabaena, and Nostoc genera originating from Serbia, with the aim of determining the chemical profile of volatile organic compounds produced by these organisms. Additionally, the influence of nitrogen level during growth on the production of volatile compounds was investigated for Nostoc and Anabaena strains. In addition, multivariate techniques, namely, principal component analysis (PCA) and hierarchical cluster analysis (HCA), were used for making distinction among different microalgal strains. The results show that the main volatile compounds in these species are medium chain length alkanes, but other odorous compounds such as 2-methylisoborneol (0.51–4.48%), 2-pentylfuran (0.72–8.98%), β-cyclocitral (0.00–1.17%), and β-ionone (1.15–2.72%) were also detected in the samples. Addition of nitrogen to growth medium was shown to negatively affect the production of 2-methylisoborneol, while geosmin was not detected in any of the analyzed samples, which indicates that the manipulation of growth conditions may be useful in reducing levels of some unwanted odor-causing components. Ivan Milovanović, Aleksandra Mišan, Jelica Simeunović, Dajana Kovač, Dubravka Jambrec, and Anamarija Mandić Copyright © 2015 Ivan Milovanović et al. All rights reserved. Effect of High Temperature on the Electrochemical and Optical Properties of Emeraldine Salt Doped with DBSA and Sulfuric Acid Thu, 19 Feb 2015 09:57:59 +0000 http://www.hindawi.com/journals/jchem/2015/826358/ A comprehensive study of thermally treated polyaniline in its emeraldine salt form is presented here. It offers an understanding of the thermal stability of the polymer. Emeraldine salt was prepared by a novel emulsion polymerization pathway using dodecylbenzene sulfonic acid and sulfuric acid together as dopants. The effect of temperature and heating rate on the degradation of this emeraldine salt was studied via thermogravimetric analysis. The thermally analyzed sample was collected at various temperatures, that is, 250, 490, 500, and 1000°C. The gradual changes in the structure of the emeraldine salt were followed through cyclic voltammetry, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. Results demonstrate that emeraldine salt shows high thermal stability up to 500°C. This is much higher working temperature for the use of emeraldine salt in higher temperature applications. Further heat treatment seems to induce deprotonation in emeraldine salt. Cyclic voltammetry and ultraviolet-visible spectroscopy revealed that complete deprotonation takes place at 1000°C where it loses its electrical conductivity. It is interesting to note that after the elimination of the dopants, the basic backbone of emeraldine salt was not destroyed. The results reveal that the dopants employed have a stability effect on the skeleton of emeraldine salt. Salma Gul, Anwar-ul-Haq Ali Shah, and Salma Bilal Copyright © 2015 Salma Gul et al. All rights reserved. Stability-Indicating Photochemical Method for the Assay of Riboflavin: Lumichrome Method Thu, 19 Feb 2015 07:08:17 +0000 http://www.hindawi.com/journals/jchem/2015/256087/ A stability-indicating photochemical method for the assay of riboflavin (RF) in photodegraded samples and aged vitamin preparations has been developed. It is based on photochemical conversion of RF to lumichrome (LC) in alkaline solution under controlled conditions of light intensity, temperature, pH, time of exposure, and distance. Under these conditions about two-thirds of RF is converted to LC and on the basis of the RF : LC ratio the concentration of RF can be determined in degraded solutions. The method involves the extraction of photolyzed solutions of RF (pH 2.0) with chloroform and determination of LC along with lumiflavin (LF) by a two-component spectrometric method at 356 and 445 nm. The method has been validated and the results of the assay of RF in photodegraded solutions compare well with those of the standard USP fluorimetric method. The recovery of the method is 99–101% and the precision is within 2%. The method is stability-indicating and can be applied to the assay of RF in photodegraded solutions and aged vitamin preparations. The method is specific compared to that of the USP fluorimetric method in which the degraded LC may interfere with the fluorescence emission of RF. Iqbal Ahmad, Syed Haider Abbas, Zubair Anwar, Muhammad Ali Sheraz, Sofia Ahmed, Adeel Arsalan, and Raheela Bano Copyright © 2015 Iqbal Ahmad et al. All rights reserved. Synthesis of N,N-Diethyldithiocarbamate Nitrile Ethyl and the Chelating Behaviors with Metal Ions Mon, 16 Feb 2015 09:13:57 +0000 http://www.hindawi.com/journals/jchem/2015/252967/ The N,N-diethyldithiocarbamate nitrile ethyl (NND) was the nonionic polar collector, and it can synthesize the NND in dimethyl sulfoxide solvent. This method can effectively reduce the reaction intensity and the coefficient of the synthetic risk. The purity of NND which we synthesized is 94.23%, and the yield is 91.06%. UV analysis shows that the characteristic absorption peak wavelength of the NND is 276 nm, and its absorbance is 0.901. Based on the interaction of NND + Mn+ (Mn+ = Fe3+, Cu2+, Zn2+, Pb2+) and the quantum chemical calculation analysis of the NND and ethyl xanthate, we can conclude that the flotation performance of NND should be better than that of ethyl xanthate. Zhonghui Zhang, Lijun Shi, Wen Deng, Dengbang Jiang, and Yaozhong Lan Copyright © 2015 Zhonghui Zhang et al. All rights reserved.