International Journal of Analytical Chemistry The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Simultaneous Determination of Salicylic Acid, Jasmonic Acid, Methyl Salicylate, and Methyl Jasmonate from Ulmus pumila Leaves by GC-MS Thu, 17 Sep 2015 12:55:52 +0000 Salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate are important phytohormones and defensive signaling compounds, so it is of great importance to determine their levels rapidly and accurately. The study uses Ulmus pumila leaves infected by Tetraneura akinire Sasaki at different stages as materials; after extraction with 80% methanol and ethyl acetate and purification with primary secondary amine (PSA) and graphitized carbon blacks (GCB), the contents of signal compounds salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate were determined by GC-MS. The results showed that the level of salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate increased remarkably in U. pumila once infected by T. akinire Sasaki, but the maximums of these four compounds occurred at different times. Salicylic acid level reached the highest at the early stage, and jasmonic acid level went to the maximum in the middle stage; by contrast, change of content of methyl salicylate and methyl jasmonate was the quite opposite. Zhi-hong Huang, Zhi-li Wang, Bao-lin Shi, Dong Wei, Jian-xin Chen, Su-li Wang, and Bao-jia Gao Copyright © 2015 Zhi-hong Huang et al. All rights reserved. Ammonium Ion Exchanged Zeolite for Laser Desorption/Ionization Mass Spectrometry of Phosphorylated Peptides Sun, 13 Sep 2015 14:02:53 +0000 α-Cyano-4-hydroxycinnamic acid (CHCA), an organic matrix molecule for matrix-assisted laser desorption/ionization mass spectrometry, was adsorbed to -type zeolite surface, and this new matrix was used for the detection of low-molecular-weight compounds. It was found that this matrix could simplify the mass spectrum in the low-molecular-weight region and prevent interference from fragments and alkali metal ion adducted species. CHCA adsorbed to -type ZSM5 zeolite (CHCA/NH4ZSM5) was used to measure atropine and aconitine, two toxic alkaloids in plants. In addition, CHCA/NH4ZSM5 enabled us to detect phosphorylated peptides; peaks of the protonated peptides had higher intensities than the peaks observed using CHCA only. Mengrui Yang and Tatsuya Fujino Copyright © 2015 Mengrui Yang and Tatsuya Fujino. All rights reserved. Some Rare Earth Elements Analysis by Microwave Plasma Torch Coupled with the Linear Ion Trap Mass Spectrometry Wed, 02 Sep 2015 09:54:52 +0000 A sensitive mass spectrometric analysis method based on the microwave plasma technique is developed for the fast detection of trace rare earth elements (REEs) in aqueous solution. The plasma was produced from a microwave plasma torch (MPT) under atmospheric pressure and was used as ambient ion source of a linear ion trap mass spectrometer (LTQ). Water samples were directly pneumatically nebulized to flow into the plasma through the central tube of MPT. For some REEs, the generated composite ions were detected in both positive and negative ion modes and further characterized in tandem mass spectrometry. Under the optimized conditions, the limit of detection (LOD) was at the level 0.1 ng/mL using MS2 procedure in negative mode. A single REE analysis can be completed within 2~3 minutes with the relative standard deviation ranging between 2.4% and 21.2% (six repeated measurements) for the 5 experimental runs. Moreover, the recovery rates of these REEs are between the range of 97.6%–122.1%. Two real samples have also been analyzed, including well and orange juice. These experimental data demonstrated that this method is a useful tool for the field analysis of REEs in water and can be used as an alternative supplement of ICP-MS. Xiaohong Xiong, Tao Jiang, Wenhao Qi, Jun Zuo, Meiling Yang, Qiang Fei, Saijin Xiao, Aimin Yu, Zhiqiang Zhu, and Huanwen Chen Copyright © 2015 Xiaohong Xiong et al. All rights reserved. Risk Assessment and Prediction of Heavy Metal Pollution in Groundwater and River Sediment: A Case Study of a Typical Agricultural Irrigation Area in Northeast China Sun, 23 Aug 2015 12:39:59 +0000 The areas with typical municipal sewage discharge river and irrigation water function were selected as study sites in northeast China. The samples from groundwater and river sediment in this area were collected for the concentrations and forms of heavy metals (Cr(VI), Cd, As, and Pb) analysis. The risk assessment of heavy metal pollution was conducted based on single-factor pollution index (I) and Nemerow pollution index (NI). The results showed that only one groundwater sampling site reached a polluted level of heavy metals. There was a high potential ecological risk of Cd on the N21-2 sampling site in river sediment. The morphological analysis results of heavy metals in sediment showed that the release of heavy metals can be inferred as one of the main pollution sources of groundwater. In addition, the changes in the concentration and migration scope of As were predicted by using the Groundwater Modeling System (GMS). The predicted results showed that As will migrate downstream in the next decade, and the changing trend of As polluted areas was changed with As content districts because of some pump wells downstream to form groundwater depression cone, which made the solute transfer upstream. Shuang Zhong, Hui Geng, Fengjun Zhang, Zhaoying Liu, Tianye Wang, and Boyu Song Copyright © 2015 Shuang Zhong et al. All rights reserved. Online NIR Analysis and Prediction Model for Synthesis Process of Ethyl 2-Chloropropionate Thu, 20 Aug 2015 14:06:31 +0000 Online near-infrared spectroscopy was used as a process analysis technique in the synthesis of 2-chloropropionate for the first time. Then, the partial least squares regression (PLSR) quantitative model of the product solution concentration was established and optimized. Correlation coefficient () of partial least squares regression (PLSR) calibration model was 0.9944, and the root mean square error of correction (RMSEC) was 0.018105 mol/L. These values of PLSR and RMSEC could prove that the quantitative calibration model had good performance. Moreover, the root mean square error of prediction (RMSEP) of validation set was 0.036429 mol/L. The results were very similar to those of offline gas chromatographic analysis, which could prove the method was valid. Wei Zhang, Hang Song, Jing Lu, Wen Liu, Lirong Nie, and Shun Yao Copyright © 2015 Wei Zhang et al. All rights reserved. Quantification of Niacin and Its Metabolite Nicotinuric Acid in Human Plasma by LC-MS/MS: Application to a Clinical Trial of a Fixed Dose Combination Tablet of Niacin Extended-Release/Simvastatin (500 mg/10 mg) in Healthy Chinese Volunteers Wed, 05 Aug 2015 11:49:05 +0000 Our paper aimed to develop rapid, sensitive, and specific LC-MS/MS method for the quantification of niacin (NA) and its metabolite nicotinuric acid (NUA) in human plasma. Following protein precipitation with acetonitrile, the NA, NUA, and internal standard (5-fluorouracil) were separated on a Zorbax 300SB-C8 column (250 mm × 4.6 mm, 5 μm) with a mobile phase consisting of methanol-2 mM ammonium acetate (3 : 97, v/v) at a flow rate of 1 mL/min (split 1 : 1). A tandem mass spectrometer equipped with electrospray ionization source was used as the detector and operated in negative ion mode. The linear concentration ranges of the calibration curves were 5–800 ng/mL for NA and NUA. The intra-assay RSD for quality control (QC) samples were from 5.0% to 8.7% for NA, and 5.5% to 7.6% for NUA. The interassay RSD for QC samples were from 2.8% to 9.4% for NA, and 3.7% to 5.8% for NUA. The relative errors for QC samples were from −2.2% to 2.3% for NA, and −0.6% to 3.2% for NUA. The method was successfully applied to the investigation of the pharmacokinetic profiles of NA, NUA in human after single dose administration of Niacin extended-release/Simvastatin tablet (500 mg/10 mg). Pingping Zhang, Yantong Sun, Guobing Shi, Yin Sui, Qiuying Li, Yunbiao Tang, and Jingkai Gu Copyright © 2015 Pingping Zhang et al. All rights reserved. Fast Differential Analysis of Propolis Using Surface Desorption Atmospheric Pressure Chemical Ionization Mass Spectrometry Mon, 03 Aug 2015 12:35:02 +0000 Mass spectral fingerprints of 24 raw propolis samples, including 23 from China and one from the United States, were directly obtained using surface desorption atmospheric pressure chemical ionization mass spectrometry (SDAPCI-MS) without sample pretreatment. Under the optimized experimental conditions, the most abundant signals were detected in the mass ranges of 70 to 500 m/z and 200 to 350 m/z, respectively. Principal component analyses (PCA) for the two mass ranges showed similarities in that the colors had a significant correlation with the first two PCs; in contrast there was no correlation with the climatic zones from which the samples originated. Analytes such as chrysin, pinocembrin, and quercetin were detected and identified using multiple stage mass spectrometry within 3 min. Therefore, SDAPCI-MS can be used for rapid and reliable high-throughput analysis of propolis. Xue-yong Huang, Xia-li Guo, Huo-lin Luo, Xiao-wei Fang, Teng-gao Zhu, Xing-lei Zhang, Huan-wen Chen, and Li-ping Luo Copyright © 2015 Xue-yong Huang et al. All rights reserved. Comparative Analysis of Amino Acids, Nucleosides, and Nucleobases in Thais clavigera from Different Distribution Regions by Using Hydrophilic Interaction Ultra-Performance Liquid Chromatography Coupled with Triple Quadrupole Tandem Mass Spectrometry Tue, 28 Jul 2015 12:12:10 +0000 Thais clavigera, as function food, is distributed widely along the coasts of China. To compare and tap its potentially nutritional and functional values, hydrophilic interaction ultra-performance liquid chromatography coupled with triplequadrupole tandem mass spectrometry (HILIC-UPLC-TQ-MS/MS) was used for simultaneous identification and quantification of amino acids, nucleosides, and nucleobases in the extracts of T. clavigera from 19 sea areas in China, and a PCA was further performed for comparing their content variation in different distribution regions. The total contents of amino acids varied from 116.74 mg/g to 298.58 mg/g being higher than contents of nucleosides and nucleobases that varied from 2.65 mg/g and 20.49 mg/g. Among the habitats, Hainan province had content advantages on others. By PCA, samples collected from different regions were classified into three groups. For specific constituents, lysine accounted for large part of essential amino acids; glycine and taurine also play important roles in the delicate taste and health care function of it. Inosine takes up most of total contents of nucleosides and nucleobases. These results provided good data for establishing quality standard of T. clavigera related products and their further development and utilization. Yahui Ge, Yuping Tang, Sheng Guo, Xin Liu, Zhenhua Zhu, Pei Liu, and Jin-ao Duan Copyright © 2015 Yahui Ge et al. All rights reserved. Development and Validation of a GC-MS Method for the Detection and Quantification of Clotiapine in Blood and Urine Specimens and Application to a Postmortem Case Tue, 07 Jul 2015 09:35:30 +0000 Introduction. Clotiapine is an atypical antipsychotic of the dibenzothiazepine class introduced in a few European countries since 1970, efficient in treatment-resistant schizophrenic patients. There is little published data on the therapeutic and toxic concentrations of this drug. Aims. The aim of the present study is the development and validation of a method that allows the detection and quantification of clotiapine in blood and urine specimens by gas chromatography-mass spectrometry (GC-MS). Methods. Validation was performed working on spiked postmortem blood and urine samples. Samples were extracted with liquid-liquid extraction (LLE) technique at pH 8.5 with n-hexane/dichloromethane (85/15 v/v) and analysis was followed by GC-MS. Methadone-d9 was used as internal standard. Results. The limit of detection (LOD) was 1.2 and 1.3 ng/mL for urine and blood, respectively, while the lower limit of quantification (LLOQ) was 3.9 and 4.3 ng/mL, respectively. Linearity, precision, selectivity, accuracy, and recovery were also determined. The method was applied to a postmortem case. The blood and urine clotiapine concentrations were 1.32 and 0.49 μg/mL, respectively. Conclusions. A reliable GC-MS method for the detection and quantification of clotiapine in blood and urine samples has been developed and fully validated and then applied to a postmortem case. Giulio Mannocchi, Flaminia Pantano, Roberta Tittarelli, Miriam Catanese, Federica Umani Ronchi, and Francesco Paolo Busardò Copyright © 2015 Giulio Mannocchi et al. All rights reserved. Production of Sterilizing Agents from Calendula officinalis Extracts Optimized by Response Surface Methodology Thu, 07 May 2015 11:30:04 +0000 The aim of this study was to produce hand sterilizing liquid and wet wipes with the extracts of Calendula officinalis. Since this plant has well known antimicrobial activity due to its phytochemical constituents, the increase in the extraction yield was chosen as the principle part of the production process. To achieve the maximum yield, parameters of solid-to-liquid ratio, extraction temperature, and time were studied. The optimum conditions were determined by response surface methodology as 41°C, 7 h, and 3.3 g/200 mL for temperature, time, and solid-to-liquid ratio, respectively. The yield achieved at those conditions was found to be 90 percent. The highest amounts of flavonoids were detected at optimum, whereas the highest triterpene and saponin constituents were determined at different design points. The microbial efficiencies of extracts were determined by the inhibition of the growth of selected microorganisms. Different dilution rates and interaction times were used as parameters of inhibition. Not any of the constituent but symbiotic relation in-between reached the highest inhibition of 90 percent. The pH values of the extracts were 5.1 to 5.4. As a result, the extraction of Calendula officinalis at the optimum conditions can be used effectively in the production of wet wipes and hand sterilizing liquid. Fatih Mehmet Goktas, Bilgesu Sahin, and Sibel Yigitarslan Copyright © 2015 Fatih Mehmet Goktas et al. All rights reserved. Electrochemical Deposition and Dissolution of Thallium from Sulfate Solutions Sun, 03 May 2015 11:45:26 +0000 The electrochemical behavior of thallium was studied on glassy carbon electrodes in sulfate solutions. Cyclic voltammetry was used to study the kinetics of the electrode processes and to determine the nature of the limiting step of the cathodic reduction of thallium ions. According to the dependence of current on stirring rate and scan rate, this process is diffusion limited. Chronocoulometry showed that the electrodeposition can be performed with a current efficiency of up to 96% in the absence of oxygen. Ye. Zh. Ussipbekova, G. A. Seilkhanova, Ch. Jeyabharathi, F. Scholz, A. P. Kurbatov, M. K. Nauryzbaev, and A. Berezovskiy Copyright © 2015 Ye. Zh. Ussipbekova et al. All rights reserved. Development of HPLC Protocol and Simultaneous Quantification of Four Free Flavonoids from Dracocephalum heterophyllum Benth. Wed, 29 Apr 2015 14:26:34 +0000 Quantification of the four flavonoids, namely, luteolin, kaempferol, diosmetin, and chrysosplenetin, has been performed for the first time in 80% ethanolic extract of Dracocephalum heterophyllum B. through HPLC coupled to UV detector after optimization of extracting solvent and chromatographic conditions. Total flavonoids quantified were 0.324 mg/mL of the extract. HPLC analysis delivered contents of the luteolin, kaempferol, diosmetin, and chrysosplenetin as 0.08%, 0.14%, 0.28%, and 0.79% of the dried extract, respectively. LOD (%) values calculated were 0.04, 0.03, 0.03, and 0.08 and LOQ (%) values were 0.08, 0.12, 0.11, and 0.28 for luteolin, kaempferol, diosmetin, and chrysosplenetin, respectively. The recovery percentages for these flavonoids were within the acceptable range of 95% to 105%. Standard deviation and %RSD were calculated for each target analytes individually in extract for determining the reproducibility and accuracy of the method. In no case the %RSD was higher than 1 taking retention time as a factor while in the case of area under the curve maximum %RSD was noted in the case of diosmetin as 2.85. From our literature review regarding the plant species under study, it appears that these flavonoids have not been quantified before and are reported for the first time in this paper. Sodik Rakhmonovich Numonov, Muhammad Nasimullah Qureshi, and Haji Akber Aisa Copyright © 2015 Sodik Rakhmonovich Numonov et al. All rights reserved. Effects of Storage Temperature and Time on Stability of Serum Tacrolimus and Cyclosporine A Levels in Whole Blood by LC-MS/MS Thu, 09 Apr 2015 10:55:35 +0000 Tacrolimus and cyclosporine A are immunosuppressant drugs with narrow therapeutic windows. The aim of this study was to investigate the stability of tacrolimus and cyclosporin A levels in whole blood samples under different storage conditions. Whole blood samples were obtained from 15 patients receiving tacrolimus and 15 patients receiving cyclosporine A. Samples were immediately analyzed and then stored at different conditions (room temperature (24°C−26°C) for 24 hours, +4°C for 24 and 48 hours, and −20°C for one month) and then analyzed again. For tacrolimus, there was a significant difference between samples analyzed immediately and those kept 24 hours at room temperature () (percent change 32.89%). However, there were no significant differences between the other groups. For cyclosporine A, there was a significant difference between samples analyzed immediately and those kept 24 hours () (percent change 19.47%) and 48 hours () (percent change 15.38%) at +4°C and those kept 24 hours at room temperature () (percent change 9.71%). Samples of tacrolimus should be analyzed immediately or stored at either +4°C or −20°C, while samples of cyclosporine A should be analyzed immediately or stored at −20°C. İbrahim Kaplan, Hatice Yüksel, Osman Evliyaoğlu, M. Kemal Basarali, Gülten Toprak, Leyla Çolpan, and Velat Şen Copyright © 2015 İbrahim Kaplan et al. All rights reserved. A New Sensitive Sensor for Simultaneous Differential Pulse Voltammetric Determination of Codeine and Acetaminophen Using a Hydroquinone Derivative and Multiwall Carbon Nanotubes Carbon Paste Electrode Mon, 06 Apr 2015 12:12:30 +0000 A new sensitive sensor was fabricated for simultaneous determination of codeine and acetaminophen based on 4-hydroxy-2-(triphenylphosphonio)phenolate (HTP) and multiwall carbon nanotubes paste electrode at trace levels. The sensitivity of codeine determination was deeply affected by spiking multiwall carbon nanotubes and a modifier in carbon paste. Electron transfer coefficient, α, catalytic electron rate constant, k, and the exchange current density, , for oxidation of codeine at the HTP-MWCNT-CPE were calculated using cyclic voltammetry. The calibration curve was linear over the range 0.2–844.7 μM with two linear segments, and the detection limit of 0.063 μM of codeine was obtained using differential pulse voltammetry. The modified electrode was separated codeine and acetaminophen signals by differential pulse voltammetry. The modified electrode was applied for the determination of codeine and acetaminophen in biological and pharmaceutical samples with satisfactory results. Elahe Garazhian and M. Reza Shishehbore Copyright © 2015 Elahe Garazhian and M. Reza Shishehbore. All rights reserved. The Influence of Different Drying Methods on Constituents and Antioxidant Activity of Saffron from China Mon, 30 Mar 2015 13:17:58 +0000 More and more saffron has been cultivated in China because of the increasing saffron demand, but no paper has studied the influence of drying methods on the quality of Chinese saffron. In this paper, three different dehydration treatments applied in actual production were evaluated: dehydration with electric oven, vacuum oven, and microwave. We determined that the highest quality of saffron will be obtained when fresh saffron is treated at higher temperatures (no more than 70°C) for a long time by electric oven drying and vacuum oven drying. In microwave drying, treatments at lower microwave power and longer time benefit the quality of saffron. In addition, the influence of the drying method on antioxidants in saffron is discussed. The correlation between individual saffron profiles and the antioxidant value was estimated by spectrum-effect relationships analysis. Yingpeng Tong, Xingyi Zhu, Yongqiu Yan, Ruoxi Liu, Feng Gong, Ling Zhang, Jiangning Hu, Ling Fang, Ruwei Wang, and Ping Wang Copyright © 2015 Yingpeng Tong et al. All rights reserved. Development of a Rapid and Simple Method for Detection of Protein Contaminants in Carmine Sun, 29 Mar 2015 14:26:51 +0000 Protein contaminants in carmine can cause dyspnea and anaphylactic reactions in users and consumers of products containing this pigment. The method generally used for detection of proteins in carmine has low reproducibility and is time-consuming. In this study, a rapid, simple, and highly reproducible method was developed for the detection of protein contaminants in carmine. This method incorporates acidic protein denaturation conditions and ultrafiltration. To prevent protein aggregation, sodium dodecyl sulfate containing gel electrophoresis running buffer was used for dispersing the carmine before filtration. An ultrafiltration device was used to separate the protein contaminants from carminic acid in the carmine solution. Two ultrafiltration devices were compared, and a cylindrical device containing a modified polyethersulfone membrane gave the best results. The method had high reproducibility. Norihisa Nakayama, Yutaka Ohtsu, Daisuke Maezawa-Kase, and Ken-Ichi Sano Copyright © 2015 Norihisa Nakayama et al. All rights reserved. Extraction and Sample Preparation Tue, 24 Mar 2015 10:01:47 +0000 Mohammad Rezaee, Faezeh Khalilian, Mohammad Reza Pourjavid, Shahram Seidi, Alberto Chisvert, and Mohamed Abdel-Rehim Copyright © 2015 Mohammad Rezaee et al. All rights reserved. Arsenic, Antimony, Chromium, and Thallium Speciation in Water and Sediment Samples with the LC-ICP-MS Technique Sun, 22 Mar 2015 08:59:46 +0000 Chemical speciation is a very important subject in the environmental protection, toxicology, and chemical analytics due to the fact that toxicity, availability, and reactivity of trace elements depend on the chemical forms in which these elements occur. Research on low analyte levels, particularly in complex matrix samples, requires more and more advanced and sophisticated analytical methods and techniques. The latest trends in this field concern the so-called hyphenated techniques. Arsenic, antimony, chromium, and (underestimated) thallium attract the closest attention of toxicologists and analysts. The properties of those elements depend on the oxidation state in which they occur. The aim of the following paper is to answer the question why the speciation analytics is so important. The paper also provides numerous examples of the hyphenated technique usage (e.g., the LC-ICP-MS application in the speciation analysis of chromium, antimony, arsenic, or thallium in water and bottom sediment samples). An important issue addressed is the preparation of environmental samples for speciation analysis. Magdalena Jabłońska-Czapla Copyright © 2015 Magdalena Jabłońska-Czapla. All rights reserved. A Rapid and Accurate Extraction Procedure for Analysing Free Amino Acids in Meat Samples by GC-MS Thu, 19 Mar 2015 14:27:28 +0000 This study evaluated the use of a mixer mill as the homogenization tool for the extraction of free amino acids in meat samples, with the main goal of analyzing a large number of samples in the shortest time and minimizing sample amount and solvent volume. Ground samples (0.2 g) were mixed with 1.5 mL HCl 0.1 M and homogenized in the mixer mill. The final biphasic system was separated by centrifugation. The supernatant was deproteinized, derivatized and analyzed by gas chromatography. This procedure showed a high extracting ability, especially in samples with high free amino acid content (recovery = 88.73–104.94%). It also showed a low limit of detection and quantification (3.8 · 10−4–6.6 · 10−4 μg μL−1 and 1.3 · 10−3–2.2 · 10−2 μg μL−1, resp.) for most amino acids, an adequate precision (2.15–20.15% for run-to-run), and a linear response for all amino acids (R2 = 0.741–0.998) in the range of 1–100 µg mL−1. Moreover, it takes less time and requires lower amount of sample and solvent than conventional techniques. Thus, this is a cost and time efficient tool for homogenizing in the extraction procedure of free amino acids from meat samples, being an adequate option for routine analysis. Trinidad Pérez-Palacios, Miguel A. Barroso, Jorge Ruiz, and Teresa Antequera Copyright © 2015 Trinidad Pérez-Palacios et al. All rights reserved. An Optimized High Throughput Clean-Up Method Using Mixed-Mode SPE Plate for the Analysis of Free Arachidonic Acid in Plasma by LC-MS/MS Thu, 19 Mar 2015 14:12:57 +0000 A high throughput sample preparation method was developed utilizing mixed-mode solid phase extraction (SPE) in 96-well plate format for the determination of free arachidonic acid in plasma by LC-MS/MS. Plasma was mixed with 3% aqueous ammonia and loaded into each well of 96-well plate. After washing with water and methanol sequentially, 3% of formic acid in acetonitrile was used to elute arachidonic acid. The collected fraction was injected onto a reversed phase column at 30°C with mobile phase of acetonitrile/water (70 : 30, v/v) and detected by LC-MS/MS coupled with electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curve ranged from 10 to 2500 ng/mL with sufficient linearity (r2 = 0.9999). The recoveries were in the range of 99.38% to 103.21% with RSD less than 6%. The limit of detection is 3 ng/mL. Wan Wang, Suzi Qin, Linsen Li, Xiaohua Chen, Qunjie Wang, and Junfu Wei Copyright © 2015 Wan Wang et al. All rights reserved. Pregabalin and Tranexamic Acid Evaluation by Two Simple and Sensitive Spectrophotometric Methods Thu, 19 Mar 2015 11:07:33 +0000 This paper demonstrates colorimetric visible spectrophotometric quantification methods for amino acid, namely, tranexamic acid and pregabalin. Both drugs contain the amino group, and when they are reacted with 2,4-dinitrophenol and 2,4,6-trinitrophenol, they give rise to yellow colored complexes showing absorption maximum at 418 nm and 425 nm, respectively, based on the Lewis acid base reaction. Detailed optimization process and stoichiometric studies were conducted along with investigation of thermodynamic features, that is, association constant and standard free energy changes. The method was linear over the concentration range of 0.02–200 µgmL−1 with correlation coefficient of more than 0.9990 in all of the cases. Limit of detection was in range from 0.0041 to 0.0094 µgmL−1 and limit of quantification was in the range from 0.0137 to 0.0302 µgmL−1. Excellent recovery in Placebo spiked samples indicated that there is no interference from common excipients. The analytical methods under proposal were successfully applied to determine tranexamic acid and pregabalin in commercial products. -test and ratio were evaluated without noticeable difference between the proposed and reference methods. Nawab Sher, Nasreen Fatima, Shahnaz Perveen, Farhan Ahmed Siddiqui, and Alisha Wafa Sial Copyright © 2015 Nawab Sher et al. All rights reserved. Antibacterial, Antifungal, and Insecticidal Potentials of Oxalis corniculata and Its Isolated Compounds Thu, 19 Mar 2015 09:59:20 +0000 Oxalis corniculata is a common medicinal plant widely used against numerous infectious diseases. The agrochemical potential of methanolic extract, n-hexane, chloroform, ethyl acetate, and n-butanol fractions were assessed to measure the antibacterial, antifungal, and insecticidal activities of the plant. The crude, chloroform, and n-butanol soluble fractions showed excellent activities against Escherichia coli, Shigella dysenteriae, Salmonella typhi, and Bacillus subtilis but have no activity against Staphylococcus aureus. Similarly the crude, n-hexane, and chloroform fractions were also found to have significant activity against fungal strains including Fusarium solani, Aspergillus flexneri, and Aspergillus flavus and have no activity against Aspergillus niger. Chemical pesticides have shown very good results at the beginning, but with the passage of time the need was realized to use the natural plant sources for the safe control of insects. The current study will provide minor contribution towards it. High mortality rate was recorded for the crude extract and chloroform fraction against Tribolium castaneum. The two isolated compounds 5-hydroxy-6,7,8,4′-tetramethoxyflavone (1) and 5,7,4′-trihydroxy-6,8-dimethoxyflavone (2) were evaluated for antibacterial, antifungal, and insecticidal activities. The results showed that compound 2 was more active than compound 1 against the tested bacterial strains and insects. Azizur Rehman, Ali Rehman, and Ijaz Ahmad Copyright © 2015 Azizur Rehman et al. All rights reserved. Dramatic Improvement of Proteomic Analysis of Zebrafish Liver Tumor by Effective Protein Extraction with Sodium Deoxycholate and Heat Denaturation Thu, 19 Mar 2015 09:17:51 +0000 Majority of the proteomic studies on tissue samples involve the use of gel-based approach for profiling and digestion. The laborious gel-based approach is slowly being replaced by the advancing in-solution digestion approach. However, there are still several difficulties such as difficult-to-solubilize proteins, poor proteomic analysis in complex tissue samples, and the presence of sample impurities. Henceforth, there is a great demand to formulate a highly efficient protein extraction buffer with high protein extraction efficiency from tissue samples, high compatibility with in-solution digestion, reduced number of sample handling steps to reduce sample loss, low time consumption, low cost, and ease of usage. Here, we evaluated various existing protein extraction buffers with zebrafish liver tumor samples and found that sodium deoxycholate- (DOC-) based extraction buffer with heat denaturation was the most effective approach for highly efficient extraction of proteins from complex tissues such as the zebrafish liver tumor. A total of 4,790 proteins have been identified using shotgun proteomics approach with 2D LC, which to our knowledge is the most comprehensive study for zebrafish liver tumor proteome. Jigang Wang, Yew Mun Lee, Caixia Li, Ping Li, Zhen Li, Teck Kwang Lim, Zhiyuan Gong, and Qingsong Lin Copyright © 2015 Jigang Wang et al. All rights reserved. Application of an Activated Carbon-Based Support for Magnetic Solid Phase Extraction Followed by Spectrophotometric Determination of Tartrazine in Commercial Beverages Thu, 19 Mar 2015 09:07:04 +0000 A method is presented for magnetic solid phase extraction of tartrazine from nonalcoholic beverages. The method involves the extraction and clean-up by activated carbon covered with magnetite dispersed in the sample, followed by the magnetic isolation and desorption of the analyte by basified methanol. The tartrazine eluted from the magnetic support was determined by spectrophotometry. Under optimal conditions, the linear range of the calibration curve ranges from 3 to 30 mg L−1, with a limit of detection of 1 mg L−1. The method was validated by comparing the results with those obtained by HPLC. A precision of 5.0% was obtained in all cases and no significant differences were observed . José A. Rodríguez, Karen A. Escamilla-Lara, Alfredo Guevara-Lara, Jose M. Miranda, and Ma. Elena Páez-Hernández Copyright © 2015 José A. Rodríguez et al. All rights reserved. Extraction of HCV-RNA from Plasma Samples: Development towards Semiautomation Thu, 19 Mar 2015 08:44:26 +0000 A semiautomated extraction protocol of HCV-RNA using Favorgen RNA extraction kit has been developed. The kit provided protocol was modified by replacing manual spin steps with vacuum filtration. The assay performance was evaluated by real-time qPCR based on Taqman technology. Assay linearity was confirmed with the serial dilutions of RTA (Turkey) containing 1 (106, 105, 104, and 103) IU mL−1. Comparison of test results obtained by two extraction methods showed a good correlation (, ) with detection limit of 102 IU mL−1. The semiautomated vacuum filtration based protocol demonstrated high throughput: 35 minutes for the extraction of a batch of 30 samples (150 µL each) with reduced labor, time, waste, and cost. Performance characteristics of semiautomated system make it suitable for use in diagnostic purpose and viral load determinations. Imran Amin, Tania Jabbar, Fawad Niazi, and Muhammad Saeed Akhtar Copyright © 2015 Imran Amin et al. All rights reserved. Comparison of Electrospray Ionization and Atmospheric Chemical Ionization Coupled with the Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Cholesteryl Esters Thu, 19 Mar 2015 08:41:33 +0000 The approach of two different ionization techniques including electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was tested for the analysis of cholesteryl esters (CEs). The retention time (RT), signal intensity, protonated ion, and product ion of CEs were compared between ESI and APCI. RT of CEs from both ionizations decreased with increasing double bonds, while it increased with longer carbon chain length. The ESI process generated strong signal intensity of precursor ions corresponding to [M+Na]+ and [M+NH4]+ regardless of the number of carbon chains and double bonds in CEs. On the other hand, the APCI process produced a protonated ion of CEs [M+H]+ with a weak signal intensity, and it is selectively sensitive to detect precursor ions of CEs with unsaturated fatty acids. The ESI technique proved to be effective in ionizing more kinds of CEs than the APCI technique. Hae-Rim Lee, Sunil Kochhar, and Soon-Mi Shim Copyright © 2015 2015 Hae-Rim Lee et al. All rights reserved. Sample Preparation and Extraction in Small Sample Volumes Suitable for Pediatric Clinical Studies: Challenges, Advances, and Experiences of a Bioanalytical HPLC-MS/MS Method Validation Using Enalapril and Enalaprilat Thu, 19 Mar 2015 08:38:06 +0000 In USA and Europe, medicines agencies force the development of child-appropriate medications and intend to increase the availability of information on the pediatric use. This asks for bioanalytical methods which are able to deal with small sample volumes as the trial-related blood lost is very restricted in children. Broadly used HPLC-MS/MS, being able to cope with small volumes, is susceptible to matrix effects. The latter restrains the precise drug quantification through, for example, causing signal suppression. Sophisticated sample preparation and purification utilizing solid-phase extraction was applied to reduce and control matrix effects. A scale-up from vacuum manifold to positive pressure manifold was conducted to meet the demands of high-throughput within a clinical setting. Faced challenges, advances, and experiences in solid-phase extraction are exemplarily presented on the basis of the bioanalytical method development and validation of low-volume samples (50 μL serum). Enalapril, enalaprilat, and benazepril served as sample drugs. The applied sample preparation and extraction successfully reduced the absolute and relative matrix effect to comply with international guidelines. Recoveries ranged from 77 to 104% for enalapril and from 93 to 118% for enalaprilat. The bioanalytical method comprising sample extraction by solid-phase extraction was fully validated according to FDA and EMA bioanalytical guidelines and was used in a Phase I study in 24 volunteers. Bjoern B. Burckhardt and Stephanie Laeer Copyright © 2015 Bjoern B. Burckhardt and Stephanie Laeer. All rights reserved. QuEChERS Method Followed by Solid Phase Extraction Method for Gas Chromatographic-Mass Spectrometric Determination of Polycyclic Aromatic Hydrocarbons in Fish Thu, 19 Mar 2015 08:27:27 +0000 A gas chromatography equipped with mass spectrometer (GCMS) method was developed and validated for determination of 16 polycyclic aromatic hydrocarbons (PAHs) in fish using modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for extraction and solid phase extraction for sample cleanup to remove most of the coextract combined with GCMS for determination of low concentration of selected group of PAHs in homogenized fish samples. PAHs were separated on a GCMS with HP-5ms Ultra Inert GC Column (30 m, 0.25 mm, and 0.25 µm). Mean recovery ranged from 56 to 115%. The extraction efficiency was consistent over the entire range where indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene showed recovery (65, 69%), respectively, at 2 µg/kg. No significant dispersion of results was observed for the other remaining PAHs and recovery did not differ substantially, and at the lowest and the highest concentrations mean recovery and RSD% showed that most of PAHs were between 70% and 120% with RSD less than 10%. The measurement uncertainty is expressed as expanded uncertainty and in terms of relative standard deviation (at 95% confidence level) is 12%. This method is suitable for laboratories engaged daily in routine analysis of a large number of samples. Mona Khorshid, Eglal R. Souaya, Ahmed H. Hamzawy, and Moustapha N. Mohammed Copyright © 2015 Mona Khorshid et al. All rights reserved. A High Throughput Method for Measuring Polycyclic Aromatic Hydrocarbons in Seafood Using QuEChERS Extraction and SBSE Thu, 19 Mar 2015 08:19:18 +0000 National Oceanic and Atmospheric Administration (NOAA) Method NMFS-NWFSC-59 2004 is currently used to quantitatively analyze seafood for polycyclic aromatic hydrocarbon (PAH) contamination, especially following events such as the Deepwater Horizon oil rig explosion that released millions of barrels of crude oil into the Gulf of Mexico. This method has limited throughput capacity; hence, alternative methods are necessary to meet analytical demands after such events. Stir bar sorptive extraction (SBSE) is an effective technique to extract trace PAHs in water and the quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction strategy effectively extracts PAHs from complex food matrices. This study uses SBSE to concentrate PAHs and eliminate matrix interference from QuEChERS extracts of seafood, specifically oysters, fish, and shrimp. This method provides acceptable recovery (65–138%) linear calibrations and is sensitive (LOD = 0.02 ppb, LOQ = 0.06 ppb) while providing higher throughput and maintaining equivalency between NOAA 2004 as determined by analysis of NIST SRM 1974b mussel tissue. Edward A. Pfannkoch, John R. Stuff, Jacqueline A. Whitecavage, John M. Blevins, Kathryn A. Seely, and Jeffery H. Moran Copyright © 2015 Edward A. Pfannkoch et al. All rights reserved. Rapid Characterization of Tanshinone Extract Powder by Near Infrared Spectroscopy Wed, 18 Mar 2015 15:39:13 +0000 Chemical and physical quality attributes of herbal extract powders play an important role in the research and development of Chinese medicine preparations. The active pharmaceutical ingredients have a direct impact on the herbal extract’s efficacy, while the physical properties of raw material affect the pharmaceutical manufacturing process and the final products’ quality. In this study, tanshinone extract powders from Salvia miltiorrhiza which are widely used for the treatment of cardiovascular diseases in the clinic are taken as the research object. Both the chemical information and physical information of tanshinone extract powders are analyzed by near infrared (NIR) spectroscopy. The partial least squares (PLS) and least square support vector machine (LS-SVM) models are investigated to build the relationship between NIR spectra and reference values. PLS models performed well for the content of crytotanshinone, tanshinone IIA, the moisture, and average median particle size, while, for specific surface area and tapped density, the LS-SVM models performed better than the PLS models. Results demonstrated NIR to be a valid and fast process analytical technology tool to simultaneously determine multiple quality attributes of herbal extract powders and indicated that there existed some nonlinear relationship between NIR spectra and physical quality attributes. Gan Luo, Bing Xu, Xinyuan Shi, Jianyu Li, Shengyun Dai, and Yanjiang Qiao Copyright © 2015 Gan Luo et al. All rights reserved.