International Journal of Analytical Chemistry The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. The Adsorption of Pb, Zn, Cu, Ni, and Cd by Modified Ligand in a Single Component Aqueous Solution: Equilibrium, Kinetic, Thermodynamic, and Desorption Studies Thu, 18 May 2017 00:00:00 +0000 In this investigation, an amino functionalized adsorbent was developed by grafting 4-aminobenzoic acid onto the backbone of cross-linked chitosan beads. The 3 sets of beads including chitosan (CX), glutaraldehyde cross-linked chitosan (CCX), and 4-aminobenzoic acid grafted cross-linked chitosan (FGCX) were characterized by FTIR, XRD, SEM, and TGA. The water content and amine concentration of FGCX were determined. The effect of adsorption parameters was studied and the optimum was used for further studies. Equilibrium data was obtained from the adsorption experiment carried out at different initial concentration; the data were applied in isotherm, thermodynamics, and kinetic studies. The Langmuir and Dubinin-Kaganer-Radushkevich (DKR) models were successful in describing the isotherm data for the considered metal ions while the Freundlich and Temkin model fit some of the considered metal ions. Pseudo-second-order and intraparticle model described the kinetic data quite well. Thermodynamic parameters such as Gibb’s free energy change (), enthalpy change (), and entropy change () were calculated and the results showed that the adsorption of Pb, Cu, Ni, Zn, and Cd ions onto FGCX is spontaneous and endothermic in nature. Regeneration of the spent adsorbent was efficient for the considered metal ions. E. Igberase, P. Osifo, and A. Ofomaja Copyright © 2017 E. Igberase et al. All rights reserved. Formulation Development of High Strength Gel System and Evaluation on Profile Control Performance for High Salinity and Low Permeability Fractured Reservoir Tue, 16 May 2017 07:52:10 +0000 For the large pores and cracks of reservoirs with low temperatures, high salinity, and low permeability, a new type of high strength gel ABP system is developed in this paper. The defects of conventional gels such as weak gel strength, no gelling, and easy dehydration are overcome under the conditions of low temperature and high salinity. The temperature and salt resistance, plugging characteristics, and EOR of the gel system are studied. Under the condition of 32°C and 29500 mg/L salinity, the ABP system formulation is for 0.3% crosslinking agent A + 0.09% coagulant B + 3500 mg/L polymer solution P. The results show that when the temperature was increased, the delayed crosslinking time of the system was shortened and the gel strength was increased. The good plugging characteristics of the ABP system were reached, and the plugging rate was greater than 99% in cores with different permeability. A good profile control performance was achieved, and the recovery rate was improved by 19.27% on the basis of water flooding. In the practical application of the gel system, the salinity of formation water and the permeability of fractures are necessary to determine the appropriate formulation. Chengli Zhang, Guodong Qu, and Guoliang Song Copyright © 2017 Chengli Zhang et al. All rights reserved. Analyses of Mineral Content and Heavy Metal of Honey Samples from South and East Region of Turkey by Using ICP-MS Thu, 11 May 2017 00:00:00 +0000 The substantial of mineral ingredients in honey may symbolize the existence of elements in the plants and soil of the vicinity wherein the honey was taken. The aim of this study was to detect the levels of 13 elements (Potassium (K), Sodium (Na), Calcium (Ca), Iron (Fe), Zinc (Zn), Cadmium (Cd), Copper (Cu), Manganese (Mn), Lead (Pb), Nickel (Ni), Chromium (Cr), Aluminum (Al), and Selenium (Se)) in unifloral and multifloral honey samples from south and east regions of Turkey. Survey of 71 honey samples from seven different herbal origins, picked up from the south and east region of Turkey, was carried out to determine their mineral contents during 2015-2016. The mineral contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The most abundant minerals were K, Na, and Ca ranging within 1.18–268 ppm, 0.57–13.1 ppm, and 0.77–4.5 ppm, respectively. Zn and Cu were the most abundant trace element while Pb, Cd, Ni, and Cr were the lowest heavy metals in the honey samples surveyed, with regard to the concentrations of heavy metals such as Zn, Cu, Pb, Cd, Ni, and Cr suggested and influence of the botanical origin of element composition. Geochemical and geographical differences are probably related to the variations of the chemical components of honey samples. Serap Kılıç Altun, Hikmet Dinç, Nilgün Paksoy, Füsun Karaçal Temamoğulları, and Mehmet Savrunlu Copyright © 2017 Serap Kılıç Altun et al. All rights reserved. Rapid Determination of Isomeric Benzoylpaeoniflorin and Benzoylalbiflorin in Rat Plasma by LC-MS/MS Method Mon, 08 May 2017 00:00:00 +0000 Benzoylpaeoniflorin (BP) is a potential therapeutic agent against oxidative stress related Alzheimer’s disease. In this study, a more rapid, selective, and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed to determine BP in rat plasma distinguishing with a monoterpene isomer, benzoylalbiflorin (BA). The method showed a linear response from 1 to 1000 ng/mL (). The precision of the interday and intraday ranged from 2.03 to 12.48% and the accuracy values ranged from −8.00 to 10.33%. Each running of the method could be finished in 4 minutes. The LC-MS/MS method was validated for specificity, linearity, precision, accuracy, recovery, and stability and was found to be acceptable for bioanalytical application. Finally, this fully validated method was successfully applied to a pharmacokinetic study in rats following oral administration. Chuanqi Zhou and Xiaoke Wang Copyright © 2017 Chuanqi Zhou and Xiaoke Wang. All rights reserved. New Modified UPLC/Tandem Mass Spectrometry Method for Determination of Risperidone and Its Active Metabolite 9-Hydroxyrisperidone in Plasma: Application to Dose-Dependent Pharmacokinetic Study in Sprague-Dawley Rats Wed, 03 May 2017 00:00:00 +0000 Sensitive and specific liquid-chromatography tandem mass spectrometry (UPLC-MS/MS) assay has been developed and validated for simultaneous quantification of risperidone (RIS) and its active metabolite 9-hydroxyrisperidone (9-OH-RIS) in rat plasma using olanzapine (OLA) as internal standard (IS). Pharmacokinetics of risperidone and its active metabolite 9-hydroxyrisperidone was compared across different doses (0.3, 1.0, and 6.0 mg/kg). Serial blood sample was collected over a time of 48 hours and analyzed for risperidone and its active metabolite 9-hydroxyrisperidone. The pharmacokinetics parameters including , , and AUC were determined for risperidone and its active ingredient. The method was linear in the concentration range of 0.2–500 ng/mL for risperidone and 9-OH-risperidone, with coefficients of determination greater than 0.998 and lower limit of quantitation of 0.2 ng/mL. Blood levels of risperidone and its active metabolite were roughly dose-proportional. The method developed herein is simple and rapid and was successfully applied for dose-dependent pharmacokinetic study. Essam Ezzeldin, Marwa Tammam, and Nisreen F. Abo Talib Copyright © 2017 Essam Ezzeldin et al. All rights reserved. Analyses of Ferrous and Ferric State in DynabiTab Using Mössbauer Spectroscopy Sun, 09 Apr 2017 07:09:08 +0000 Antianemic medicament ferrous gluconate, ferrous fumarate, and a Dynabi tablet with a basic iron bearing ingredient were studied with the use of Mössbauer spectroscopy. Room temperature spectra of ferrous gluconate gave clear evidence that the two phases of iron were present: ferrous (Fe2+) as a major one with a contribution at and above 91 a.u.% and ferric (Fe3+) whose contribution was found to be ~9 a.u.%. In the case of ferrous fumarate, a single phase was measured corresponding to ferrous (Fe2+) state. A Dynabi tablet consists of ferrous fumarate and ferrous fumarate. The ferric phase in ferrous gluconate is able to be reached about ~3.6 a.u.% in a tablet. Young Rang Uhm, Jae Cheong Lim, and Sang Mu Choi Copyright © 2017 Young Rang Uhm et al. All rights reserved. Simultaneous Determination of Preservatives in Dairy Products by HPLC and Chemometric Analysis Mon, 03 Apr 2017 09:18:16 +0000 Cheese and yogurt are two kinds of nutritious dairy products that are used worldwide. The major preservatives in dairy products are sodium benzoate, potassium sorbate, and natamycin. The maximum permitted levels for these additives in cheese and yogurt are established according to Iranian national standards. In this study, we developed a method to detect these preservatives in dairy products by reversed phase chromatography with UV detection in 220 nm, simultaneously. This method was performed on C18 column with ammonium acetate buffer () and acetonitrile (73 : 27 v/v) as mobile phase. The method was carried out on 195 samples in 5 kinds of commercial cheeses and yogurts. The results demonstrated insufficient separation where limit of detection (LOD) and limit of quantitation (LOQ) ranged from 0.326 to 0.520 mg/kg and 0.989 to 1.575 mg/kg in benzoate and sorbate, respectively. The correlation coefficient of each calibration curve was mostly higher than 0.997. All samples contained sodium benzoate in various ranges. Natamycin and sorbate were detected in a remarkable amount of samples, while, according to Iranian national standard, only sorbate is permitted to be added in processed cheeses as a preservative. In order to control the quality of dairy products, determination of preservatives is necessary. Fatemeh Zamani Mazdeh, Sima Sasanfar, Anita Chalipour, Elham Pirhadi, Ghazal Yahyapour, Armin Mohammadi, Akram Rostami, Mohsen Amini, and Mannan Hajimahmoodi Copyright © 2017 Fatemeh Zamani Mazdeh et al. All rights reserved. Detection of Cu2+ in Water Based on Histidine-Gold Labeled Multiwalled Carbon Nanotube Electrochemical Sensor Mon, 20 Mar 2017 08:59:24 +0000 Based on the strong interaction between histidine and copper ions and the signal enhancement effect of gold-labeling carbon nanotubes, an electrochemical sensor is established and used to measure copper ions in river water. In this study the results show that the concentrations of copper ion have well linear relationship with the peak current in the range of 10−11–10−7 mol/L, and the limit of detection is 10−12 mol/L. When using this method to detect copper ions in the Xiangjiang River, the test results are consistent with the atomic absorption method. This study shows that the sensor is convenient to be used in daily monitoring of copper ions in river water. Rilong Zhu, Gangqiang Zhou, Fengxia Tang, Chunyi Tong, Yeyao Wang, and Jinsheng Wang Copyright © 2017 Rilong Zhu et al. All rights reserved. GC Method Validation for the Analysis of Menthol in Suppository Pharmaceutical Dosage Form Mon, 06 Mar 2017 00:00:00 +0000 Menthol is widely used as a fragrance and flavor in the food and cosmetic industries. It is also used in the medical and pharmaceutical fields for its various biological effects. Gas chromatography (GC) is considered to be a sensitive method for the analysis of menthol. GC chromatographic separation was developed using capillary column (VF-624) and a flame ionization detector (FID). The method was validated as per ICH guidelines for various parameters such as precision, linearity, accuracy, solution stability, robustness, limit of detection, and quantification. The tested validation parameters were found to be within acceptable limits. The method was successfully applied for the quantification of menthol in suppositories formulations. Quality control departments and official pharmacopeias can use our developed method in the analysis of menthol in pharmaceutical dosage formulation and raw material. Murad N. Abualhasan, Abdel Naser Zaid, Nidal Jaradat, and Ayman Mousa Copyright © 2017 Murad N. Abualhasan et al. All rights reserved. Green Synthesis and Characterization of Silver Nanoparticles Using Citrullus lanatus Fruit Rind Extract Mon, 20 Feb 2017 00:00:00 +0000 The wide-scale application of silver nanoparticles (AgNPs) in areas such as chemical sensing, nanomedicine, and electronics has led to their increased demand. Current methods of AgNPs synthesis involve the use of hazardous reagents and toxic solvents. There is a need for the development of new methods of synthesizing AgNPs that use environmentally safe reagents and solvents. This work reports a green method where silver nanoparticles (AgNPs) were synthesized using silver nitrate and the aqueous extract of Citrullus lanatus fruit rind as the reductant and the capping agent. The optimized conditions for the AgNPs synthesis were a temperature of 80°C, pH 10, 0.001 M AgNO3, 250 g/L watermelon rind extract (WMRE), and a reactant ratio of 4 : 5 (AgNO3 to WMRE). The AgNPs were characterized by Ultraviolet-Visible (UV-Vis) spectroscopy exhibiting a at 404 nm which was consistent with the spectra of spherical AgNPs within the wavelength range of 380–450 nm, and Cyclic Voltammetry (CV) results showed a distinct oxidation peak at +291 mV while the standard reference AgNPs (20 nm diameter) oxidation peak occurred at +290 mV, and Transmission Electron Microscopy (TEM) revealed spherical shaped AgNPs. The AgNPs were found to have an average diameter of  nm. Michael Ndikau, Naumih M. Noah, Dickson M. Andala, and Eric Masika Copyright © 2017 Michael Ndikau et al. All rights reserved. Identification and Quantification of Glucosinolates in Kimchi by Liquid Chromatography-Electrospray Tandem Mass Spectrometry Sun, 19 Feb 2017 00:00:00 +0000 A novel and simple method for detecting five glucosinolates (glucoalyssin, gluconapin, glucobrassicanapin, glucobrassicin, and 4-methoxyglucobrassicin) in kimchi was developed using liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS). The chromatographic peaks of the five glucosinolates were successfully identified by comparing their retention times, mass spectra. The mobile phase was composed of A (acetonitrile) and B (water). As for glucosinolate, the relative quantities were found through sinigrin, and five different compounds that have not been previously discovered in kimchi were observed. Monitoring was carried out on the glucosinolate in 20 kimchis distributed in markets, and this study examined the various quality and quantity compositions of the five components. The glucoalyssin content ranged from 0.00 to 7.07 μmol/g of day weight (DW), with an average content of 0.86 μmol/g of DW, whereas the gluconapin content ranged from 0.00 to 5.85 μmol/g of DW, with an average of 1.17 μmol/g of DW. The content of glucobrassicanapin varied between 0.00 and 11.87 μmol/g of DW (average = 3.03 μmol/g of DW), whereas that of glucobrassicin varied between 0.00 and 0.42 μmol/g of DW (average = 0.06 μmol/g of DW). The 4-methoxyglucobrassicin content ranged from 0.12 to 9.36 μmol/g of DW (average = 3.52 μmol/g of DW). A comparison of the contents revealed that, in most cases, the content of 4-methoxyglucobrassicin was the highest. Ho Jin Kim, Mi Jin Lee, Min Hee Jeong, and Jang Eok Kim Copyright © 2017 Ho Jin Kim et al. All rights reserved. Particle Morphology Analysis of Biomass Material Based on Improved Image Processing Method Sun, 19 Feb 2017 00:00:00 +0000 Particle morphology, including size and shape, is an important factor that significantly influences the physical and chemical properties of biomass material. Based on image processing technology, a method was developed to process sample images, measure particle dimensions, and analyse the particle size and shape distributions of knife-milled wheat straw, which had been preclassified into five nominal size groups using mechanical sieving approach. Considering the great variation of particle size from micrometer to millimeter, the powders greater than 250 μm were photographed by a flatbed scanner without zoom function, and the others were photographed using a scanning electron microscopy (SEM) with high-image resolution. Actual imaging tests confirmed the excellent effect of backscattered electron (BSE) imaging mode of SEM. Particle aggregation is an important factor that affects the recognition accuracy of the image processing method. In sample preparation, the singulated arrangement and ultrasonic dispersion methods were used to separate powders into particles that were larger and smaller than the nominal size of 250 μm. In addition, an image segmentation algorithm based on particle geometrical information was proposed to recognise the finer clustered powders. Experimental results demonstrated that the improved image processing method was suitable to analyse the particle size and shape distributions of ground biomass materials and solve the size inconsistencies in sieving analysis. Zhaolin Lu, Xiaojuan Hu, and Yao Lu Copyright © 2017 Zhaolin Lu et al. All rights reserved. Evaluation of Phenolic Compounds and Antioxidant and Antimicrobial Activities of Some Common Herbs Thu, 16 Feb 2017 11:27:24 +0000 The study was designed to evaluate the phenolic, flavonoid contents and antioxidant and antimicrobial activities of onion (Allium cepa), garlic (Allium sativum), mint (Mentha spicata), thyme (Thymus vulgaris), oak (Quercus), aloe vera (Aloe barbadensis Miller), and ginger (Zingiber officinale). All extracts showed a wide range of total phenolic contents, that is, 4.96 to 98.37 mg/100 g gallic acid equivalents, and total flavonoid contents, that is, 0.41 to 17.64 mg/100 g catechin equivalents. Antioxidant activity (AA) was determined by measuring reducing power, inhibition of peroxidation using linoleic acid system, and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity. Different extracts inhibited oxidation of linoleic acid by 16.6–84.2% while DPPH radical scavenging activity (IC50 values) ranged from 17.8% to 79.1 μg/mL. Reducing power at 10 mg/mL extract concentration ranged from 0.11 to 0.84 nm. Furthermore the extracts of these medicinal herbs in 80% methanol, 80% ethanol, 80% acetone, and 100% water were screened for antimicrobial activity by disc diffusion method against selected bacterial strains, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Pasteurella multocida, and fungal strains, Aspergillus niger, Aspergillus flavus, Rhizopus solani, and Alternaria alternata. The extracts show better antimicrobial activity against bacterial strains as compared to fungal strains. Results of various assays were analyzed statistically by applying appropriate statistical methods. Muhammad Abdul Qadir, Syeda Kiran Shahzadi, Asad Bashir, Adil Munir, and Shabnam Shahzad Copyright © 2017 Muhammad Abdul Qadir et al. All rights reserved. Determination of Ten Corticosteroids in Illegal Cosmetic Products by a Simple, Rapid, and High-Performance LC-MS/MS Method Tue, 14 Feb 2017 00:00:00 +0000 The aim of our present work was the development of a rapid high-performance liquid chromatography method with electrospray ionization and tandem mass spectrometry detection (LC-ESI-MS/MS) for the determination of several corticosteroids in cosmetic products. Corticosteroids are suspected to be illegally added in cosmetic preparations in order to enhance the curative effect against some skin diseases. Sample preparation step consists in a single extraction with acetonitrile followed by centrifugation and filtration. The compounds were separated by reversed-phase chromatography with water and acetonitrile (both with 0.1% formic acid) gradient elution and detected by ESI-MS positive and negative ionization mode. The method was validated at the validation level of 0.1 mg kg−1. Linearity was studied in the 5–250 μg L−1 range and linear coefficients () were all over 0.99. The accuracy and precision of the method were satisfactory. The LOD ranged from 0.085 to 0.109 mg kg−1 and the LOQ from 0.102 to 0.121 mg kg−1. Mean recoveries for all the analytes were within the range 91.9–99.2%. The developed method is sensitive and useful for detection, quantification, and confirmation of these corticosteroids in cosmetic preparations and can be applied in the analysis of the suspected samples under investigation. Vita Giaccone, Giuseppe Polizzotto, Andrea Macaluso, Gaetano Cammilleri, and Vincenzo Ferrantelli Copyright © 2017 Vita Giaccone et al. All rights reserved. Acetylcholinesterase Inhibitors Assay Using Colorimetric pH Sensitive Strips and Image Analysis by a Smartphone Mon, 13 Feb 2017 00:00:00 +0000 Smartphones are widely spread and their usage does not require any trained personnel. Recently, smartphones were successfully used in analytical chemistry as a simple detection tool in some applications. This paper focuses on immobilization of acetylcholinesterase (AChE) onto commercially available pH strips with stabilization in the gelatin membrane. AChE degrades acetylcholine into choline and acetic acid which causes color change of acid-base indicator. Smartphone served as a tool for measurement of indicator color change from red to orange while inhibitors blocked this process. AChE inhibitors were measured with limits of detection, 149 nM and 22.3 nM for galanthamine and donepezil, respectively. Organic solvents were measured for method interferences. Measurement procedure was performed on 3D printed holder and digital photography was evaluated using red-green-blue (RGB) channels. The invented assay was validated to the standard Ellman’s test and verified on murine plasma samples spiked with inhibitors. We consider that the assay is fully suitable for practical performance. Adam Kostelnik, Alexander Cegan, and Miroslav Pohanka Copyright © 2017 Adam Kostelnik et al. All rights reserved. Determination of Levels of Organochlorine, Organophosphorus, and Pyrethroid Pesticide Residues in Vegetables from Markets in Dar es Salaam by GC-MS Thu, 09 Feb 2017 00:00:00 +0000 This study investigated the levels of pesticides and metabolites in vegetables from major markets in Dar es Salaam city, Tanzania. Samples of fresh cabbage, spinach, and onions from the markets were analysed for pesticide residues. Extraction was performed using acetone followed by dichloromethane : cyclohexane mixture and the extracts were cleaned up using Florisil. The compounds were determined by gas chromatography-mass spectrometry (GC-MS). Pesticides and metabolites were detected in 72.2% of the samples. The detected pesticide residues and their highest mean concentrations were p,p′-DDT 4.00 × 10−3 mg/kg, p,p′-DDD 6.40 × 10−1 mg/kg, o,p′-DDD 1.00 × 10−2 mg/kg, α-endosulfan 6.00 × 10−1 mg/kg, β-endosulfan 2.10 × 10−1 mg/kg, chlorpyrifos 3.00 mg/kg, and cypermethrin 4.00 × 10−2 mg/kg. The most frequently detected compounds were p,p′-DDD and chlorpyrifos. The order of contamination was spinach > cabbage > onions. Generally, there were no significant variations in concentrations of pesticide residues among samples and sampling sites, which indicated similarities in contamination patterns. The concentrations of contaminants were above the maximum residue limits (MRLs) in 33.3–50% of the samples. The findings indicated risks and concerns for public health. John A. M. Mahugija, Farhat A. Khamis, and Esther H. J. Lugwisha Copyright © 2017 John A. M. Mahugija et al. All rights reserved. Chemical Compositional Analysis of Catalytic Hydroconversion Products of Heishan Coal Liquefaction Residue Mon, 30 Jan 2017 10:02:29 +0000 Liquefaction residue of Heishan bituminous coal (HLR) was subject to two hydroconversion reactions under 5 MPa initial pressure of hydrogen at 300°C for 3 h, without catalyst and with acid supported catalyst (ASC), respectively. The reaction products were analyzed with gas chromatography/mass spectrometer (GC/MS). The results show that 222 organic compounds were detected totally in the products and they can be divided into alkanes, aromatic hydrocarbons (AHCs), phenols, ketones, ethers, and other species (OSs). The yield of hydroconversion over the ASC is much higher than that without catalyst. The most abundant products are aromatic hydrocarbons in the reaction products from both catalytic and noncatalytic reactions of HLR. The yield of aromatic hydrocarbons in the reaction product from hydroconversion with the ACS is considerably higher than that from hydroconversion without a catalyst. Xiaoming Yue, Yajun Wu, Shuangquan Zhang, Xiaoqin Yang, and Xianyong Wei Copyright © 2017 Xiaoming Yue et al. All rights reserved. The Influence of Electrolytic Concentration on the Electrochemical Deposition of Calcium Phosphate Coating on a Direct Laser Metal Forming Surface Sun, 29 Jan 2017 07:21:23 +0000 A calcium phosphate (CaP) coating on titanium surface enhances its biocompatibility, thus facilitating osteoconduction and osteoinduction with the inorganic phase of the human bone. Electrochemical deposition has been suggested as an effective means of fabricating CaP coatings on porous surface. The purpose of this study was to develop CaP coatings on a direct laser metal forming implant using electrochemical deposition and to investigate the effect of electrolytic concentration on the coating’s morphology and structure by X-ray diffraction, scanning electron microscopy, water contact angle analysis, and Fourier transform infrared spectroscopy. In group 10−2, coatings were rich in dicalcium phosphate, characterized to be thick, layered, and disordered plates. In contrast, in groups 10−3 and 10−4, the relatively thin and well-ordered coatings predominantly consisted of granular hydroxyapatite. Further, the hydrophilicity and cell affinity were improved as electrolytic concentration increased. In particular, the cells cultured in group 10−3 appeared to have spindle morphology with thick pseudopodia on CaP coatings; these spindles and pseudopodia strongly adhered to the rough and porous surface. By analyzing and evaluating the surface properties, we provided further knowledge on the electrolytic concentration effect, which will be critical for improving CaP coated Ti implants in the future. Qianyue Sun, Yuhui Yang, Wenjing Luo, Jinghui Zhao, and Yanmin Zhou Copyright © 2017 Qianyue Sun et al. All rights reserved. Simultaneous Determination and Stability Studies on Diminazene Diaceturate and Phenazone Using Developed Derivative Spectrophotometric Method Thu, 26 Jan 2017 06:50:26 +0000 This work presents UV first derivative spectrophotometry as a precise, accurate, and feasible method for simultaneous determination of diminazene diaceturate and phenazone in bulk and dosage forms. The absorbance values of diminazene diaceturate and phenazone aqueous mixture were obtained at 398 nm and 273 nm, respectively. The developed method was proved to be linear over the concentration ranges (2–10) μg/mL and (2.496–12.48) μg/mL for diminazene diaceturate and phenazone, respectively, with good correlation coefficients (not less than 0.997). The detection and quantitation limits were found to be (LOD = 0.63 and 0.48 μg/mL; LOQ = 1.92 and 1.47 μg/mL, resp.). The developed method was employed for stability studies of both drugs under different stress conditions. Diminazene diaceturate was prone to degrade at acidic pH via first-order kinetics. The degradation process was found to be temperature dependent with an activation energy of 7.48 kcal/mole. Photo-stability was also investigated for this drug. Ruaa Mohamed Akode, Shaza Wagiealla Shantier, Elrasheed Ahmed Gadkariem, and Magdi Awadalla Mohamed Copyright © 2017 Ruaa Mohamed Akode et al. All rights reserved. Quantitative Analysis of Volatile Impurities in Diallyldimethylammonium Chloride Monomer Solution by Gas Chromatography Coupled with Liquid-Liquid Extraction Mon, 23 Jan 2017 00:00:00 +0000 The quantitative analysis method for volatile impurities in diallyldimethylammonium chloride (DADMAC) monomer solution was established in this paper. The volatile impurities were quantitatively analyzed with trichloromethane as extraction solvent and n-hexane as internal standard by using gas chromatography (GC) coupled with solvent extraction, and the chromatographic conditions, quantitative methods, and extraction conditions were systematically investigated in detail. The results showed that excellent linear relationships of 5 volatile impurities (dimethylamine, allyldimethylamine, allyl chloride, allyl alcohol, and allyl aldehyde) were obtained in the range of 1–100 mg·L−1. The method also showed good specificity, recovery (95.0%–107.5%), and relative standard deviation (RSD, 1.40%–7.67%). This method could accurately detect the whole volatile impurities in DADMAC monomer solution quantitatively in one time with a low detection limit. Furthermore, this method is conducive to the preparation of highly pure DADMAC monomer and the development of national and international standards of the DADMAC monomer product quality, and the results could provide a strong foundation for the regulation and mechanism research of impurities on monomer reactivity in polymerization. Cheng Liu, Yuejun Zhang, Haiying Wang, and Weixin Wang Copyright © 2017 Cheng Liu et al. All rights reserved. Trace Detection of Metalloporphyrin-Based Coordination Polymer Particles via Modified Surface-Enhanced Raman Scattering Assisted by Surface Metallization Mon, 26 Dec 2016 13:43:56 +0000 This study proposed a facile method to detect metalloporphyrin-based coordination polymer particles (Z-CPPs) in aqueous solution by modified surface-enhanced Raman scattering (SERS). The SERS-active particles are photodeposited on the surface of Z-CPPs, offering an enhanced Raman signal for the trace detection of Z-CPPs. Yu Sun and Alessio Caravella Copyright © 2016 Yu Sun and Alessio Caravella. All rights reserved. Simultaneous Determination of Bergapten, Imperatorin, Notopterol, and Isoimperatorin in Rat Plasma by High Performance Liquid Chromatography with Fluorescence Detection and Its Application to Pharmacokinetic and Excretion Study after Oral Administration of Notopterygium incisum Extract Mon, 26 Dec 2016 12:02:58 +0000 A specific, sensitive, and reliable high performance liquid chromatography with fluorescence detection (HPLC-FLD) was first optimized and then used in the simultaneous quantification of bergapten, imperatorin, notopterol, and isoimperatorin in rat plasma using osthole as the internal standard. Liquid-liquid extraction with ethyl acetate was employed in treating the rat plasma samples obtained. Separation was carried out with a Hedera™ ODS column (4.6 × 250 mm, 5 μm) by gradient elution at a temperature of 40°C. Excitation and emission of the fluorescence detector were set to 300 and 490 nm, respectively. The lower limits of quantification for bergapten, imperatorin, notopterol, and isoimperatorin in rat plasma were 4, 40, 4, and 2 ng mL−1, respectively. The intraday and interday precision and accuracy for the four coumarins were within acceptable criteria. The recovery of the method was satisfactory with a range of 80.3–114%. The validated method was successfully used for the simultaneous determination of the four coumarins in Notopterygium incisum extracts and also for the pharmacokinetic and excretion study of bergapten, imperatorin, notopterol, and isoimperatorin in rats. John Teye Azietaku, Xie-an Yu, Jin Li, Jia Hao, Jun Cao, Mingrui An, Zhijing Tan, and Yan-xu Chang Copyright © 2016 John Teye Azietaku et al. All rights reserved. Application of Long-Range Surface Plasmon Resonance for ABO Blood Typing Thu, 22 Dec 2016 07:38:56 +0000 In this study, we demonstrate a long-range surface plasmon resonance (LR-SPR) biosensor for the detection of whole cell by captured antigens A and B on the surface of red blood cells (RBCs) as a model. The LR-SPR sensor chip consists of high-refractive index glass, a Cytop film layer, and a thin gold (Au) film, which makes the evanescent field intensity and the penetration depth longer than conventional SPR. Therefore, the LR-SPR biosensor has improved capability for detecting large analytes, such as RBCs. The antibodies specific to blood group A and group B (Anti-A and Anti-B) are covalently immobilized on a grafting self-assembled monolayer (SAM)/Au surface on the biosensor. For blood typing, RBC samples can be detected by the LR-SPR biosensor through a change in the refractive index. We determined that the results of blood typing using the LR-SPR biosensor are consistent with the results obtained from the agglutination test. We obtained the lowest detection limits of 1.58 × 105 cells/ml for RBC-A and 3.83 × 105 cells/ml for RBC-B, indicating that the LR-SPR chip has a higher sensitivity than conventional SPR biosensors (3.3 × 108 cells/ml). The surface of the biosensor can be efficiently regenerated using 20 mM NaOH. In summary, as the LR-SPR technique is sensitive and has a simple experimental setup, it can easily be applied for ABO blood group typing. Wanida Tangkawsakul, Toemsak Srikhirin, Kazunari Shinbo, Keizo Kato, Futao Kaneko, and Akira Baba Copyright © 2016 Wanida Tangkawsakul et al. All rights reserved. Determination of Spatial Chromium Contamination of the Environment around Industrial Zones Thu, 01 Dec 2016 14:06:31 +0000 This study was conducted to determine the spatial levels of chromium contamination of water, agricultural soil, and vegetables in the leather tanning industrial areas using spectrophotometric methods. The results showed elevated accumulation of total Cr ranging from  mg/L to  mg/L,  mg/Kg to  mg/Kg, and  mg/Kg to  mg/Kg in water, agricultural soil, and vegetable samples, respectively. The highest levels of chromium (VI) found from the speciation study were  mg/Kg and  mg/L in soil and water samples, respectively, which decreased with distance from the tannery. Among the vegetables, the highest load of Cr(VI) was detected in onion root ( mg/Kg) and the lowest ( mg/Kg) in fruit of green pepper. The detected levels of Cr in all of the suggested samples were above the WHO permissible limits. The variations of the levels Cr(III) and Cr(VI) contamination of the environment with distance from the tannery were statistically significant (). Similarly, significant difference in the levels of Cr among the tested vegetables was recorded. The levels increased with decreasing distance from the effluent channel. Dereje Homa, Ermias Haile, and Alemayehu P. Washe Copyright © 2016 Dereje Homa et al. All rights reserved. Corrigendum to “Extraction of HCV-RNA from Plasma Samples: Development towards Semiautomation” Tue, 29 Nov 2016 06:34:42 +0000 Imran Amin, Tania Jabbar, Fawad Ali, and Muhammad Saeed Akhtar Copyright © 2016 Imran Amin et al. All rights reserved. Cauliflower Leave, an Agricultural Waste Biomass Adsorbent, and Its Application for the Removal of MB Dye from Aqueous Solution: Equilibrium, Kinetics, and Thermodynamic Studies Tue, 15 Nov 2016 08:44:29 +0000 Cauliflower leaf powder (CLP), a biosorbent prepared from seasonal agricultural crop waste material, has been employed as a prospective adsorbent for the removal of a basic dye, methylene blue (MB) from aqueous solution by the batch adsorption method under varying conditions, namely, initial dye concentration, adsorbent dose, solution pH, and temperature. Characterization of the material by FTIR and SEM indicates the presence of functional groups and rough coarse surface suitable for the adsorption of methylene blue over it. Efforts were made to fit the isotherm data using Langmuir, Freundlich, and Temkin equation. The experimental data were best described by Freundlich isotherm model, with an adsorption capacity of 149.22 mg/g at room temperature. To evaluate the rate of methylene blue adsorption onto CLP, pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were employed. The experimental data were best described by the pseudo-second-order kinetic model. Evaluation of thermodynamic parameters such as changes in enthalpy, entropy, and Gibbs’ free energy showed the feasible, spontaneous, and exothermic nature of the adsorption process. On the basis of experimental results obtained, it may be concluded that the CLP prepared from agricultural waste has considerable potential as low-cost adsorbent in wastewater treatment for the removal of basic dye, MB. Seraj Anwar Ansari, Fauzia Khan, and Anees Ahmad Copyright © 2016 Seraj Anwar Ansari et al. All rights reserved. Innovative Monitoring of Atmospheric Gaseous Hydrogen Fluoride Thu, 13 Oct 2016 08:07:34 +0000 Hydrogen fluoride (HF) is a basic raw material for a wide variety of industrial products, with a worldwide production capacity of more than three million metric tonnes. A novel method for determining particulate fluoride and gaseous hydrogen fluoride in air is presented herewith. Air was sampled using miniaturised 13 mm Swinnex two-stage filter holders in a medium-flow pumping system and through the absorption of particulate fluoride and HF vapours on cellulose ester filters uncoated or impregnated with sodium carbonate. Furthermore, filter desorption from the holders and the extraction of the pentafluorobenzyl ester derivative based on solid-phase microextraction were performed using an innovative robotic system installed on an xyz autosampler on-line with gas chromatography (GC)/mass spectrometry (MS). After generating atmospheres of a known concentration of gaseous HF, we evaluated the agreement between the results of our sampling method and those of the conventional preassembled 37 mm cassette (±8.10%; correlation coefficient: 0.90). In addition, precision (relative standard deviation for , 4.3%), sensitivity (0.2 μg/filter), and linearity (2.0–4000 μg/filter; correlation coefficient: 0.9913) were also evaluated. This procedure combines the efficiency of GC/MS systems with the high throughput (96 samples/day) and the quantitative accuracy of pentafluorobenzyl bromide on-sample derivatisation. Stefano Dugheri, Alessandro Bonari, Ilenia Pompilio, Alessandro Monti, Nicola Mucci, and Giulio Arcangeli Copyright © 2016 Stefano Dugheri et al. All rights reserved. Quantitative Scrutinization of Aflatoxins in Different Spices from Pakistan Mon, 03 Oct 2016 13:40:36 +0000 The current research work aimed to access the contamination level of aflatoxins B1, B2, G1, and G2 in the household spices that are widely consumed in huge amounts. 200 different spice samples, 100 packed and 100 unpacked, were analyzed for the aflatoxins profile by HPLC with an incidence of 61.5% contamination out of which 53.66% samples exceed the EU limit. The results disclosed that the unpacked samples are more contaminated as compared to the packed samples except for white cumin seeds. Among packed and unpacked samples of spices, the maximum value of aflatoxins was detected in fennel, that is, 27.93 μg/kg and 67.04 μg/kg, respectively. The lowest concentration of aflatoxin was detected in cinnamon in packed form (0.79 μg/kg) and in the unpacked samples of white cumin seeds which is 1.75 μg/kg. Caraway seeds and coriander in its unpacked form showed positive results whereas black pepper (packed and unpacked) was found free from aflatoxins. This is the first report on the occurrence of aflatoxins in packed and unpacked samples of spices from Pakistan. To ensure safe consumption of spices, there should be constant monitoring of aflatoxin and more studies need to be executed with the intention of preventing mycotoxin accretion in this commodity. Narjis Naz, Aiza Kashif, Kinza Kanwal, Abdul Muqeet Khan, and Mateen Abbas Copyright © 2016 Narjis Naz et al. All rights reserved. A High-Throughput Size Exclusion Chromatography Method to Determine the Molecular Size Distribution of Meningococcal Polysaccharide Vaccine Mon, 05 Sep 2016 16:24:54 +0000 Molecular size distribution of meningococcal polysaccharide vaccine is a readily identifiable parameter that directly correlates with the immunogenicity. In this paper, we report a size exclusion chromatography method to determine the molecular size distribution and distribution coefficient value of meningococcal polysaccharide serogroups A, C, W, and Y in meningococcal polysaccharide (ACWY) vaccines. The analyses were performed on a XK16/70 column packed with sepharose CL-4B with six different batches of Ingovax® ACWY, a meningococcal polysaccharide vaccine produced by Incepta Vaccine Ltd., Bangladesh. A quantitative rocket immunoelectrophoresis assay was employed to determine the polysaccharide contents of each serogroup. The calculated distribution coefficient values of serogroups A, C, W, and Y were found to be , , , and , respectively, and met the requirements of British Pharmacopeia. The method was proved to be robust for determining the distribution coefficient values which is an obligatory requirement for vaccine lot release. Imran Khan, K. M. Taufiqur Rahman, S. M. Saad Us Siraj, Mahbubul Karim, Abdul Muktadir, Arpan Maheshwari, Md Azizul Kabir, Zebun Nahar, and Mohammad Mainul Ahasan Copyright © 2016 Imran Khan et al. All rights reserved. The Development of DNA Based Methods for the Reliable and Efficient Identification of Nicotiana tabacum in Tobacco and Its Derived Products Thu, 18 Aug 2016 08:10:57 +0000 Reliable methods are needed to detect the presence of tobacco components in tobacco products to effectively control smuggling and classify tariff and excise in tobacco industry to control illegal tobacco trade. In this study, two sensitive and specific DNA based methods, one quantitative real-time PCR (qPCR) assay and the other loop-mediated isothermal amplification (LAMP) assay, were developed for the reliable and efficient detection of the presence of tobacco (Nicotiana tabacum) in various tobacco samples and commodities. Both assays targeted the same sequence of the uridine 5′-monophosphate synthase (UMPS), and their specificities and sensitivities were determined with various plant materials. Both qPCR and LAMP methods were reliable and accurate in the rapid detection of tobacco components in various practical samples, including customs samples, reconstituted tobacco samples, and locally purchased cigarettes, showing high potential for their application in tobacco identification, particularly in the special cases where the morphology or chemical compositions of tobacco have been disrupted. Therefore, combining both methods would facilitate not only the detection of tobacco smuggling control, but also the detection of tariff classification and of excise. Sukumar Biswas, Wei Fan, Rong Li, Sifan Li, Wenli Ping, Shujun Li, Alexandra Naumova, Tamara Peelen, Esther Kok, Zheng Yuan, Dabing Zhang, and Jianxin Shi Copyright © 2016 Sukumar Biswas et al. All rights reserved.