检索结果-内蒙古大学图书馆

Effect of system variables involved in packed column SFC of nevirapine as model analyte using response surface methodology: Application to retention thermodynamics, solute transfer kinetic study and binary diffusion coefficient determination

引用

JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 2005年第2期64卷 121-141页

作者： Kaul, N Agrawal, H Paradkar, AR Mahadik, KR Bharati Vidyapeeth Deemed Univ Poona Coll Pharm Dept Qual Assurance Tech Pune 411038 Maharashtra India

A multifactor optimization technique is successfully applied to study the effect of simultaneously varying the system variables on feasibility of nevirapine analysis by packed column supercritical fluid chromatography (PC-SFC). The optimal conditions were determined with the aid of the response surface methodology using 33 factorial designs. The method is based on methanol-modified carbon dioxide as the mobile phase at flow rate of 3.0 ml/min with elution through a JASCO Finepak SIL-5, [C-18 (5-micron, 25 cm x 4.6 mm, i.d.)] column using photodiode array detection. The method has been successfully used to analyze commercial solid dosage form to assess the chromatographic performance of SFC system. The present work briefs the thermodynamic applications of PC-SFC with an emphasis on the results of nevirapine. The foremost of such applications is the determination of solute diffusion coefficient in supercritical mobile phase by Taylor-Aris peak broadening technique. (c) 2005 Elsevier B.V All rights reserved.

关键词： nevirapine packed column supercritical fluid chromatography (PC-SFC) response surface methodology diode array detection thermodynamic applications diffusion coefficient Taylor-Aris peak broadening technique

来源：评论

学校读者我要写书评

暂无评论

Simultaneous determination of phenytoin and dextromethorphan in urine by solid-phase extraction and HPLC-DAD

引用

JOURNAL OF SEPARATION SCIENCE 2005年第11期28卷 1157-1162页

作者： Santagati, NA Gotti, R Ronsisvalle, G Univ Catania Fac Farm Dipartimento Sci Farmaceut I-95125 Catania Italy Univ Bologna Fac Farm Dipartimento Sci Farmaceut Bologna Italy

A rapid and simple high-performance liquid chromatographic method with photodiode array detection was developed for the separation and the simultaneous determination of phenytoin and dextromethorphan in human urine. Analysis was performed in less than 4.5 min in isocratic mode on a reversed-phase C-18 column (5 mu m;150 x 4.6 mm) using a mobile phase composed of acetonitrile-buffer phosphate 0.01 M (60:40, v/v) adjusted to pH 6.0, at 1 mL/min flow rate and UV absorbance at 210 nm. The elution order of analytes was dextromethorphan (DXM), Internal Standard (IS), and phenytoin (PHT). Calibration curves were linear in the 7.5-25 mu g/mL range for PHT and in the 10-30 mu g/mL range for DXM. Spike recoveries for urine samples prepared at three spiking levels ranged from 97.8 to 102.3% for PHT and from 94.8 to 100.4% for DXM. The detection limit (LOD) values ranged from 0.08 mu g/mL for PHT to 0.5 mu g/mL for DXM. The quantitation limit (LOQ) values ranged from 0.3 mu g/mL for PHT to 1.6 mu g/mL for DXM. The sample preparation method involves a rapid and simple procedure based on solid-phase extraction using a C-18 reversed-phase column. Validation of the optimised method was carried out according to the ICH guidelines. The method developed in this study allows the reliable simultaneous analysis of PHT and DXM, drugs that were never quantified together in previously reported analytical methods. The described method has the advantage of being rapid and easy and it could be applied in therapeutic monitoring of these drugs in human urine of epileptic patients.

关键词： phenytoin dextromethorphan urine solid-phase extraction HPLC diode array detection

来源：评论

学校读者我要写书评

暂无评论

High-performance liquid chromatographic determination of Levetiracetam in human plasma: comparison of different sample clean-up procedures

引用

BIOMEDICAL CHROMATOGRAPHY 2004年第1期18卷 37-44页

作者： Pucci, V Bugamelli, F Mandrioli, R Ferranti, A Kenndler, E Raggi, MA Univ Bologna Dept Pharmaceut Sci I-40126 Bologna Italy Univ Vienna Inst Analyt Chem A-1090 Vienna Austria

An accurate and precise high-performance liquid chromatographic method using diode array detection for the determination of the novel antiepileptic, Levetiracetam, has been developed. Three clean-up procedures for the analysis of Levetiracetam in human plasma were implemented and evaluated, namely solid-phase extraction, deproteinization by addition of organic solvents and formation of insoluble salts. Adenosine was used as the internal standard for all three sample pretreatment procedures. Among the several cartridges used for solid-phase extraction, the hydrophilic-lypophilic balance (Oasis((R)) HLB) phase provides the best extraction yield of Levetiracetam, together with high precision. With the two other clean-up procedures involving plasma deproteinization by addition of methanol or zinc sulphate, lower sensitivity and precision of the assays were obtained. However, they are cheaper and faster when compared with the solid-phase extraction procedure. Copyright (C) 2004 John Wiley Sons, Ltd.

关键词： antiepileptic solid-phase extraction deproteinization diode array detection

来源：评论

学校读者我要写书评

暂无评论

LC-DAD UV and LC-MS for the analysis of isoflavones and flavones from in vitro and in vivo biomass of Genista tinctoria L.

引用

CHROMATOGRAPHIA 2004年第3-4期60卷 179-185页

作者： Luczkiewcz, M Glód, D Baczek, T Bucinski, A Med Univ Gdansk Fac Pharm Dept Pharmacognosy PL-80416 Gdansk Poland Med Univ Gdansk Fac Pharm Dept Biopharmaceut & Pharmacodynam PL-80416 Gdansk Poland Polish Acad Sci Div Food Sci Inst Anim Reprod & Food Res PL-10747 Olsztyn Poland

Conditions were determined for the separation of a complex set of isoflavones and flavones (free aglycones, monoglucosides, diglucosides and esters) by HPLC-DAD UV and MS detection. A good separation of all analytes was obtained and satisfactory peak shapes were achieved by gradient elution on an RP C18 column. The method was then applied to carry out qualitative and quantitative analysis of bioflavonoids present in the herb and in vitro cultures of Genista tinctoria L. Electrospray ionisation mass spectrometry in the negative mode was used to identify individual flavonoids in G. tinctoria plant material. Photodiode array detection was also utilised in flavonoid characterisation. All flavonoid compounds were then quantified using an internal standard. The method developed is useful for monitoring the process of flavonoid biosynthesis in biomass obtained through in vitro cultures.

关键词： column liquid chromatography mass spectrometry diode array detection flavones and isoflavones Genisto tinctoria L.

来源：评论

学校读者我要写书评

暂无评论

Development of a high pressure liquid chromatography method for the determination of mycophenolic acid and its glucuronide metabolite in small volumes of plasma from paediatric patients

引用

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS 2004年第1期35卷 87-92页

作者： Watson, DG Araya, FG Galloway, PJ Beattie, TJ Univ Strathclyde SIBS Dept Pharmaceut Sci Glasgow G4 0NR Lanark Scotland Royal Hosp Sick Children Dept Biochem Glasgow G3 8SJ Lanark Scotland Royal Hosp Sick Children Dept Nephrol Glasgow G3 8SJ Lanark Scotland

In order to facilitate the simultaneous determination of the levels of mycophenolic acid (MPA) and mycophenolic acid glucuronide (MPAG) in plasma samples a step wise gradient high performance liquid chromatography (HPLC) method was developed using UV detection system and naproxen as an internal standard. The analytes were extracted from plasma using Strata-X polymeric solid phase extraction (SPE) cartridges. Separation was achieved within a total chromatographic run time of 18 min at 1.0ml/min flow rate using a Hv PURITY(R) C18 column. The method was found to be linear over the concentration range investigated, 1.0-16 mug/ml (r > 0.99) for MPA and 10-160 mug/ml (r > 0.99) for MPAG. The limit of detection was 0.1 mug/ml for both MPAG and MPA. The intra- and inter-day imprecisions expressed as R.S.D. were 7.8 and 6.6%, respectively, for MPA (1 mug/ml) and 6.2% and 5.6%, respectively, for MPAG (20 mug/ml). The average extraction recovery from plasma was 93.06%, for MPA and 92.41% for MPAG. The method developed was found to be accurate and precise in quantifying the level of MPA and MPAG over a their therapeutic range of concentrations in small volumes of plasma and thus can be effectively used in the routine drug monitoring procedures and pharmacokinetic studies. It was also developed in such a way that it should be easily coupled to an electro-spray ionization mass spectrometer should greater sensitivity be required. (C) 2004 Elsevier B.V. All rights reserved.

关键词： mycophenolic acid glucuronide HPLC diode array detection solid phase extraction

来源：评论

学校读者我要写书评

暂无评论

Analysis of benzodiazepines in dynamically coated capillaries by CE-DAD, CE-MS and CE-MS²

引用

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS 2004年第3期34卷 595-606页

作者： Vanhoenacker, G de l'Escaille, F De Keukeleire, D Sandra, P Univ Ghent Fac Sci Lab Separat Sci Dept Organ Chem B-9000 Ghent Belgium Analis SA B-5000 Namur Belgium Univ Ghent Fac Pharmaceut Sci Lab Phytochem & Pharmacognosy B-9000 Ghent Belgium

The applicability of a low pH volatile electrolyte for fast analysis of benzodiazepines with CE-MS was investigated. The electrolyte is based on a commercially available CEofix buffer system that produces a substantial and highly reproducible electroosmotic flow through a dynamic double coating principle. The system was first evaluated with a mixture of benzodiazepine standards in CE-DAD and the electrolyte composition was further optimized for CE-MS. The LOD for the six selected benzodiazepines with CE-MS was ca. 100 ppb, except for diazepam, for which the LOD was lower than 50 ppb. RSDs varied from 0.51 to 1.02% (n = 7) for migration times and from 4.75 to 11.80% (n = 7) for peak areas. The method was successfully applied to the analysis of a spiked urine sample after solid-phase extraction (SPE). CE-MS2 was performed on a standard mixture. (C) 2003 Elsevier B.V. All rights reserved.

关键词： benzodiazepines capillary electrophoresis dynamic coating diode array detection mass spectroscopy

来源：评论

学校读者我要写书评

暂无评论

A rapid HPLC-DAD method for the analysis of fluoxetine and norfluoxetine in plasma from overdose patients

引用

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS 2004年第2期36卷 351-356页

作者： Sabbioni, C Bugamelli, F Varani, G Mercolini, L Musenga, A Saracino, MA Fanali, S Raggi, MA Univ Bologna Alma Mater Studiorum Fac Pharm Dept Pharmaceut Sci I-40126 Bologna Italy Univ Ferrara Dept Chem I-44100 Ferrara Italy CNR Inst Chem Methodol I-00016 Monterotondo Rome Italy

There is a need for fast, simple and reliable analytical methods for the analysis of fluoxetine and norfluoxetine in patients who voluntarily or involuntarily have taken an overdose of the drug. A new liquid chromatographic method with diode array detection is presented herein for the determination of fluoxetine and its main active metabolite in human plasma for toxicological purposes. A mobile phase composed of acetonitrile and aqueous tetramethylammonium perchlorate allows to obtain the complete separation of the analytes on a C 18 reversed phase column. The fast and accurate sample pre-treatment step is carried out by means of solid-phase extraction using hydrophilic-lipophilic balance cartridges and loading 100 muL of plasma only. This procedure gives satisfactory extraction yield values, as well as good plasma sample purification from matrix interference. Linearity was obtained in the 150-3000 ng/mL range for both analytes. Selectivity with respect to other psychotropic drugs was satisfactory. The method seems to be suitable for the analysis of fluoxetine and its metabolite in human plasma for depressed patients in overdose. (C) 2004 Elsevier B.V. All rights reserved.

关键词： fluoxetine norfluoxetine toxicological analysis human plasma liquid chromatography diode array detection

来源：评论

学校读者我要写书评

暂无评论

Distribution and contents of phenolic compounds in eighteen Scandinavian berry species

引用

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2004年第14期52卷 4477-4486页

作者： Määttä-Riihinen, KR Kamal-Eldin, A Mattila, PH González-Paramás, AM Törrönen, AR Univ Kuopio Inst Appl Biotechnol FIN-70211 Kuopio Finland Univ Kuopio Food & Hlth Res Ctr FIN-70211 Kuopio Finland Swedish Univ Agr Sci Dept Food Sci SLU S-75007 Uppsala Sweden MTT Agrifood Res Finland Food Res FIN-31600 Jokioinen Finland Univ Salamanca Fac Farm Area Nutr & Bromatol E-37007 Salamanca Spain

Berries contain a wide range of phenolic compounds in different conjugated forms, a fact that makes their simultaneous analysis a difficult task. In this work, soluble and insoluble phenolic compounds were identified and quantified in 18 species of berries by reversed phase high-performance liquid chromatography combined with diode array detection. The analytical results and literature data were used for the identification of the predominant conjugated hydroxycinnamic acids, flavonol glycosides, and anthocyanins in berries from six families, viz. Grossulariaceae, Ericaceae, Rosaceae, Empetraceae, Elaeagnaceae, and Caprifoliaceae. The study showed distinctive similarities among berry species of the same family in the distribution of conjugated forms of phenolic compounds but differences in chromatographic profiles of conjugates and compositions of aglycones especially in the case of anthocyanins. The chromatographic profiles of chokeberry and the related sweet rowanberry (Rosaceae) were exceptionally similar. These data are informative to studies on the authenticity of berry raw materials as well as to those on the evaluation of berries as sources of phenolic compounds.

关键词： Berries phenolic compounds HPLC diode array detection

来源：评论

学校读者我要写书评

暂无评论

High-performance liquid chromatography (HPLC) analysis of phenolic compounds in berries with diode array and electrospray ionization mass spectrometric (MS) detection:: Ribes species

引用

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2003年第23期51卷 6736-6744页

作者： Määttä, KR Kamal-Eldin, A Törrönen, AR Univ Kuopio Inst Appl Biotechnol FIN-70211 Kuopio Finland Univ Kuopio Food & Hlth Res Ctr FIN-70211 Kuopio Finland Swedish Univ Agr Sci Dept Food Sci S-75007 Uppsala Sweden

High-performance liquid chromatography combined with diode array and electrospray ionization mass spectrometric (MS) detection was used to study phenolic compounds in berries of black, green, red, and white currants (Ribes spp.). UV-visible spectrometry was a valuable tool for the identification of the class of the phenolic compound, whereas MS and MS-MS fragmentation data were useful for further structural characterization. Distinct similarities were found in the relative distribution of conjugated forms of phenolic compounds among the four currants. Phenolic acids were found mainly as hexose esters. Flavonol glycosides and anthocyanin pigments were mainly found as 3-O-rutinosides and second as 3-O-glucosides. However, cyanidin 3-O-sambubioside and quercetin hexosidemalonate were notable phenolic compounds in red currant. Flavonol hexoside-malonates were identified and quantified in the berries of currants for the first time.

关键词： food analysis berries currants phenolic compounds HPLC mass spectrometry diode array detection

来源：评论

学校读者我要写书评

暂无评论

Chemical speciation by sequential injection analysis: an overview

引用

TALANTA 2004年第5期64卷 1109-1113页

作者： van Staden, JF Stefan, RI Univ Pretoria Dept Chem ZA-0002 Pretoria South Africa

The simplicity of the sequential injection (SIA) manifold and its low need for maintenance makes it an ideal tool in speciation. As miniaturization and reduction of reagent consumption are also ultimate goals in chemical sensing, it is useful to review the use of combined injection and programmed flow as a central issue in designing SIA systems with chemical sensors and structurally simplified chemical analysers. This overview gives an insight into the current state, analytical scope and performance characteristics of sequential injection systems as analytical tools for speciation. The suitability of SIA for speciation analysis is illustrated by the methods used in the conduits of sequential injection systems for the chemical conversion of different chemical forms into detectable chemical species. Configurations of the basic sequential injection speciation analysis systems were designed around a multi-syringe-time-based-injection system with one detector, direct and indirect speciation of different forms using a single detector including diode array detection and direct speciation of different forms using multiple detection. Examples showing the use of SIA for the simultaneous determination or speciation of metal ions, inorganic anions and organic compounds are given with some recent results from our research groups. (C) 2004 Elsevier B.V. All rights reserved.

关键词： sequential injection miniaturization diode array detection

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：