Journal of Analytical Sciences, Methods and Instrumentation最新文献_第8页

Inflection Points on Some S-Shaped Curves 某些s形曲线上的拐点

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2014-03-10 DOI: 10.4236/JASMI.2014.41004

A. Michałowska-Kaczmarczyk, T. Michałowski, A. Asuero

引用次数: 2

Use of a Mid-Infrared Free-Electron Laser (MIR-FEL) for Dissociation of the Amyloid Fibril Aggregates of a Peptide 使用中红外自由电子激光(MIR-FEL)解离肽的淀粉样纤维聚集体

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2014-03-10 DOI: 10.4236/JASMI.2014.41002

T. Kawasaki, T. Imai, K. Tsukiyama

{"title":"Use of a Mid-Infrared Free-Electron Laser (MIR-FEL) for Dissociation of the Amyloid Fibril Aggregates of a Peptide","authors":"T. Kawasaki, T. Imai, K. Tsukiyama","doi":"10.4236/JASMI.2014.41002","DOIUrl":"https://doi.org/10.4236/JASMI.2014.41002","url":null,"abstract":"Amyloid fibrils are deposited in various \u0000tissues in the body, and are linked to the putative causes of serious diseases \u0000such as amyloidosis. Although the conditions of the disease would be expected \u0000to improve if the fibril structure could be destroyed, the aggregated structure \u0000is stable under physiological conditions. Recently, we found that the amyloid \u0000fibrils of lysozyme could be refolded into their active form by using a \u0000mid-infrared free-electron laser (MIR-FEL) tuned to the amide I band \u0000(corresponding to the C=O stretch vibration), with the MIR-FEL having specific \u0000oscillation characteristics of a picosecond pulse structure, a tunable \u0000wavelength within mid-infrared frequencies, and high photon density. In the \u0000study, we tested the usability of the FEL for dissociation of aggregates of \u0000pathological amyloid fibrils by using a short peptide of human thyroid hormone. \u0000The fibrils (after being placed on a glass slide) were irradiated using the FEL \u0000tuned to the amide I band (1644 cm?1), and those in situ were \u0000analyzed by Congo-Red assay, scanning-electron microscopy, and \u0000transmission-electron microscopy. All of the results obtained using these \u0000microscopic analyses indicated that the amyloid fibril formation was \u0000considerably decreased by FEL irradiation. Moreover, upon irradiation, a strong \u0000fibril peak at the amide I band in the infrared spectrum was transformed into a \u0000broad peak. These results imply that the β-sheet-rich structure of the \u0000amyloid fibrils changed into non-ordered or unspecified structures after the \u0000FEL irradiation. This FEL irradiation system, combined with various analytical \u0000methods, shows promise for the dissociation of amyloid aggregates.","PeriodicalId":14932,"journal":{"name":"Journal of Analytical Sciences, Methods and Instrumentation","volume":"1 1","pages":"9-18"},"PeriodicalIF":0.0,"publicationDate":"2014-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89611900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Development and Application of a Validated HPLC Method for the Determination of Clindamycin Palmitate Hydrochloride in Marketed Drug Products: An Optimization of the Current USP Methodology for Assay HPLC法测定市售药品中盐酸克林霉素棕榈酸酯含量的建立与应用:现行USP方法的优化

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-10-08 DOI: 10.4236/JASMI.2013.34026

Geoffrey K. Wu, Abhay Gupta, M. Khan, P. Faustino

{"title":"Development and Application of a Validated HPLC Method for the Determination of Clindamycin Palmitate Hydrochloride in Marketed Drug Products: An Optimization of the Current USP Methodology for Assay","authors":"Geoffrey K. Wu, Abhay Gupta, M. Khan, P. Faustino","doi":"10.4236/JASMI.2013.34026","DOIUrl":"https://doi.org/10.4236/JASMI.2013.34026","url":null,"abstract":"A \u0000simple efficient isocratic reversed-phase HPLC method was developed and \u0000validated for the determination of clindamycin palmitate hydrochloride (CPH) \u0000and its commercially available oral solution products. Separation was achieved \u0000on a Phenomenex Zorbax (Luna) cyano column (150 × 4.6 mm, 5 μm) with a Phenomenex cyano guard cartridge \u0000(4 × 3.0 mm) on \u0000Agilent 1050 series HPLC system. CPH and its resolution standard lincomycin \u0000were eluted isocratically at a flow rate of 1 mL/min with a simplified mobile \u0000phase (potassium phosphate buffer (5 mM, pH 3.0)—acetonitrile—tetrahydrofuran \u0000(20:75:5, v/v/v)) and detected at 210 nm. The column was maintained at 25?C. \u0000The method was validated according to USP category I requirements. Robustness \u0000and forced degradation studies were also conducted. CPH marketed drug products \u0000were obtained from a drug distributor and assayed for potency using the validated \u0000method. Validation acceptance criteria were met in all cases. The analytical \u0000range for CPH was 15 - 500 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific and \u0000robust. Both accuracy (92.0% - 103.8%) and precision (0.67% - 1.52%) were established across the analytical range for low, intermediate \u0000and high QC concentrations. Method applicability was demonstrated by analyzing \u0000two marketed products of CPH, in which results showed potency >98%. The \u0000method was determined to be an enhancement over the current USP methodology for \u0000assay as a result of increased efficiency, reduced organic solvents and the \u0000elimination of matrix modifiers. This method was successfully applied for the \u0000quality assessment of: 1) currently marketed drug products and 2) will in \u0000future assess the product quality of novel dosage forms of CPH for pediatric \u0000use.","PeriodicalId":14932,"journal":{"name":"Journal of Analytical Sciences, Methods and Instrumentation","volume":"8 1","pages":"202-211"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77991363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

NAA Algerian Laboratory Evaluation Processed by WEPAL and IAEA during 2011-2012 2011-2012年由WEPAL和国际原子能机构处理的NAA阿尔及利亚实验室评估

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-10-08 DOI: 10.4236/JASMI.2013.34024

L. Hamidatou, H. Slamene, T. Akhal, S. Begaa, M. Messaoudi, Zouranen Boussaad

{"title":"NAA Algerian Laboratory Evaluation Processed by WEPAL and IAEA during 2011-2012","authors":"L. Hamidatou, H. Slamene, T. Akhal, S. Begaa, M. Messaoudi, Zouranen Boussaad","doi":"10.4236/JASMI.2013.34024","DOIUrl":"https://doi.org/10.4236/JASMI.2013.34024","url":null,"abstract":"Participation in inter-comparison programs is an important process to enhance the accuracy and precision of the analytical techniques used in the laboratories. At Es-Salam Research Reactor, our laboratory uses two functional analytical techniques such as INAA and k0-INAA in the research projects and for the completion of the service works. Recently, our laboratory has participated in two inter-comparison tests organized by IAEA within the framework of the AFRA project to assess the analytical performance of eighteen (18) African analytical laboratories participating in the RAF/4/ 022 project, Enhancement of Research Reactor Utilization and Safety by taking part in analytical proficiency testing IAEA in conjunction with WEPAL, the Wageningen Evaluating Programs for Analytical Laboratories. The Proficiency Testing tests related to the determination of major, minor and trace elements in materials of the International Soil and Plant Analytical Exchange (Wepal codes ISE, IPE), were held in the fourth quarter of 2011 and the first quarter of 2012, respectively. Concentrations of thirty (30) elements such as Al, As, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Fe, Ga, K, La, Mg, Mo, Mn, Na, Nd, Rb, Sb, Sc, Sr, Th, Ti, U, V, W, Zn, Zr were determined in ISE and IPE samples. All results were evaluated and reported in this paper.","PeriodicalId":14932,"journal":{"name":"Journal of Analytical Sciences, Methods and Instrumentation","volume":"49 1","pages":"184-192"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76994022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Silicotungstic Acid Modified Bentonite: An Efficient Catalyst for Synthesis of Acetal Derivatives of Aldehydes and Ketones 硅钨酸改性膨润土:合成醛酮缩醛衍生物的高效催化剂

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-10-08 DOI: 10.4236/JASMI.2013.34025

R. Chaudhary, M. Datta

引用次数: 3

A New SPME Thermal Desorption Interface for HPLC 一种新型高效液相色谱SPME热脱附界面

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-10-08 DOI: 10.4236/JASMI.2013.34028

J. Acevedo, Mohamed Nour Kayali Sayadi, L. M. Díez

引用次数: 3

Optical Rotatory Dispersion Measurement of D-Glucose with Fixed Polarizer Analyzer Accessory in Conventional Spectrophotometer 用常规分光光度计中固定偏光分析仪附件测量d -葡萄糖的旋光色散

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-10-08 DOI: 10.4236/JASMI.2013.34030

A. Penzkofer

引用次数: 14

Volatile Components in the Flower, Pedicellate Ovary and Aqueous Residue of Cymbidium sp. (ORCHIDACEAE) 大花蕙兰花、花梗子房和水残中的挥发性成分

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-10-08 DOI: 10.4236/JASMI.2013.34027

V. Gaytán, M. R. Mendoza, Marcos Soto Hernández, L. Trejo-Téllez, Martha Elena Pedraza Santos, G. V. Ponce

{"title":"Volatile Components in the Flower, Pedicellate Ovary and Aqueous Residue of Cymbidium sp. (ORCHIDACEAE)","authors":"V. Gaytán, M. R. Mendoza, Marcos Soto Hernández, L. Trejo-Téllez, Martha Elena Pedraza Santos, G. V. Ponce","doi":"10.4236/JASMI.2013.34027","DOIUrl":"https://doi.org/10.4236/JASMI.2013.34027","url":null,"abstract":"Cymbidium sp. has several ornamental, medicinal and cosmetic uses. Essential oils were obtained through extraction by hydrodistillation of flower and pedicellate ovary. The chromatographic profile was obtained by thin layer chromatography (TLC), combined with gas chromatography-mass spectrometry (GC/MS), for the identification and relative quantification of various substances in three samples from the orchid (flower, pedicellate ovary and aqueous residue). With TLC, five compounds were identified in the flower, with the most abundant being terpineol, linalool and zingiberene, and five in the pedicellate ovary, with borneol, cineole, and β-bisabolene being in the greatest concentration, while for the aqueous residue, the most abundant was geraniol. Using GC/MS, 25 volatile components associated with the flower were identified, of which the most abundant were linalool (22.92%), 4-methyl-phenol (15.07%) and p-Menth-1-en-8-ol (12.32%). In pedicellate ovaries, 13 components were identified, with the most abundant being 4-methyl-phenol (31.24%), bicycle [4.4.0] dec-1-ene, 2-isopropyl-5-methyl-9-methylene-(17.74%) and 2-hexanone (10.24%), while in the aqueous residue 18 components were found, with the most abundant being 4-methyl-phenol (18.71%) and 2- cyclohexen-1-ol (14.60%).","PeriodicalId":14932,"journal":{"name":"Journal of Analytical Sciences, Methods and Instrumentation","volume":"36 1","pages":"212-218"},"PeriodicalIF":0.0,"publicationDate":"2013-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78746137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Low Level Determination of Genotoxic Impurity in Deferasirox Formulation 去铁霉制剂中遗传毒性杂质的低水平测定

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-10-08 DOI: 10.4236/JASMI.2013.34023

Pravish Kumar Tiwari, P. Sathe, Navin Devadiga

引用次数: 1

An Ion-Pair HPLC Method for Simultaneous Determination of Exogenous Phosphocreatine and Its Metabolite Creatine and Related ATP in Rabbit Plasma and RBC: Application to a Pharmacokinetic Study 离子对高效液相色谱法同时测定兔血浆和红细胞中外源性磷酸肌酸及其代谢产物肌酸和相关ATP:应用于药动学研究

Journal of Analytical Sciences, Methods and Instrumentation Pub Date : 2013-09-23 DOI: 10.4236/JASMI.2013.33A003

Li Lv, Heng Xi, G. Han

{"title":"An Ion-Pair HPLC Method for Simultaneous Determination of Exogenous Phosphocreatine and Its Metabolite Creatine and Related ATP in Rabbit Plasma and RBC: Application to a Pharmacokinetic Study","authors":"Li Lv, Heng Xi, G. Han","doi":"10.4236/JASMI.2013.33A003","DOIUrl":"https://doi.org/10.4236/JASMI.2013.33A003","url":null,"abstract":"A specific, precise and accurate \u0000ion-pair HPLC-UV method has been developed and validated for simultaneous determination \u0000of phosphocreatine (PCr), and its metabolite creatine (Cr) as well as related \u0000ATP in plasma and red blood cell (RBC) of rabbits. After addition of TMP as IS, \u0000the samples were deproteinized with 6% PCA. The analytes were separated on a \u0000Kromasil C18 column using a tertiary gradient mobile phase composed of buffer A \u0000(0.2% KH2PO4 + 0.08% tetrabutyl ammonium hydrogen \u0000sulphate, pH 3.0), buffer B (buffer A adjusted to pH 7.5 with 1 mol/L NaOH) and \u0000MeOH. Detection wavelengths were set at 210 nm for PCr and Cr and 260 nm for \u0000ATP and TMP. Some blank samples were initially run for baseline subtraction. The linear \u0000detection responses were obtained for PCr concentration over a range of 10 - 7500 mg/ml (plasma) and 5 - 2500 mg/ml (RBC) and for both Cr and ATP \u0000concentrations of 10 - 1500 mg/ml (plasma) and 5 - 750 mg/ml (RBC) (r > 0.99). The QC samples of 3 analytes \u0000showed intra-day and inter-day precisions (RSD) of - 107%. The method was successfully used to simultaneously determine plasma \u0000and RBC concentrations of the 3 analytes and to study pharmacokinetics after iv \u0000administration of PCr to rabbits.","PeriodicalId":14932,"journal":{"name":"Journal of Analytical Sciences, Methods and Instrumentation","volume":"39 1","pages":"17-23"},"PeriodicalIF":0.0,"publicationDate":"2013-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73528783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5