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Simultaneous determination of abacavir, efavirenz and valganciclovir in human serum samples by isocratic HPLC-DAD detection

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CHROMATOGRAPHIA 2007年第1-2期66卷 S25-S30页

作者： Dogan-Topal, B. Ozkan, S. A. Uslu, B. Ankara Univ Fac Pharm Dept Analyt Chem TR-06100 Ankara Turkey

A rapid, sensitive, and specific reverse phase high performance liquid chromatography with diode array detection procedure for the simultaneous determination of abacavir, efavirenz and valganciclovir in spiked human serum is described. Separation was performed on a 5 Pm Waters Spherisorb column (250 x 4.6 mm ID) with acetonitrile: methanol:KH2PO4 (at pH 5.00) (40:20:40 v/v/v) isocratic elution at a flow rate of 1.0 mL min(-1). Calibration curves were constructed in the range of 50-30,000 ng mL(-1) for abacavir and efavirenz, and 1030,000 ngmL(-1) for valganciclovir in serum samples. The limit of detection and limit of quantification concentrations of the HPLC method were 3.80 and 12.68 ng mL(-1) for obacavir, 2.61 and 8.69 ng mL(-1) for efavirenz, 1.30 and 4.32 ng mL(-1) for valganciclovir. The method has been applied, without any interference from excipients or endogenous substances, for the simultaneous determination of these three compounds in human serum.

关键词： column liquid chromatography diode array detection abacavir efavirenz valganciclovir in human serum

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HPLC analysis of in vivo metabolites of 4-nitrobenzoic acid [(5-nitro-2-thiopheneyl)methylenelhydrazide in rats

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EUROPEAN JOURNAL OF DRUG METABOLISM AND PHARMACOKINETICS 2007年第4期32卷 197-203页

作者： Kocyigit-Kaymakcioglu, Bedia Unsalan, Seda Kucukguzel, S. Guniz Sener, Goksel Rollas, Sevim Marmara Univ Fac Pharm Dept Pharmaceut Chem TR-34668 Istanbul Turkey Marmara Univ Fac Pharm Dept Pharmacol TR-34668 Istanbul Turkey

The in vivo metabolism of 4-nitrobenzoic acid [(5-nitro-2-thiopheneyl)methylenelhydrazide (substrate), a model that represents hydrazide hydrazone compounds, was investigated in the rat. The metabolites were monitored in rat plasma at certain time intervals. The substrate was dissolved in dimethylsulfoxide (DMSO)/water (1:4) and administered intraperitoneally at dose of 100 mg/kg and 500 mg/kg. Blood samples were collected at 30 min, then at 1, 2, 4, 8, 12 and 24 h post-administration. The chromatographic separation of the substrate and its metabolites was performed on a Novapak C 18 (Phenomenex) (150 mm x 4.6 mm i.d., 5-mu m particle size) using a mobile phase consisting of phosphate buffer: acetonitrile (90: 10, v/v) with a linear gradient system. From the biotransformation of this compound, 4-nitrobenzoic acid (M3) was identified together with the substrate, as evidenced by high pressure liquid chromatography (HPLC)-UV/ diode array detection (DAD).

关键词： hydrazone in vivo metabolism diode array detection

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An analysis of Maillard reaction products in ethanolic glucose-glycine solution

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FOOD CHEMISTRY 2007年第1期102卷 281-287页

作者： Shen, Szu-Chuan Tseng, Kou-Chan Wu, James Swi-Bea Natl Taiwan Univ Inst Food Sci & Technol Taipei 106 Taiwan

The present study compared the Maillard reaction products in ethanolic and aqueous glucose-glycine solutions. The pH 4.3, 0.2 M glucose-0.2 M glycine solutions were prepared and heated. HPLC-DAD (diode array detection) was then used to analyse the browned solutions, the ethyl acetate extracts of the solutions, and the coloured bands in TLC of the extracts. HMF (5-hydroxymethyl-2-furaldehyde) was found in both of the browned aqueous and ethanolic solutions, while 2-hydroxymethylfuran was found only in the browned ethanolic solution. HMF and 2-acetylpyrrole appear in the ethyl acetate extract of both systems, whereas 2-acetyl-1-methylpyrrole is present only in the extract of the ethanolic solution. The difference in profile of products in the aqueous and the ethanolic solutions indicates that the mechanisms of Maillard reaction in these two systems are not exactly the same. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： Maillard reaction ethanolic diode array detection 5-hydroxymethyl-2-furaldehyde glucose-glycine

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Validation of a HPLC method for the quantification and purity determination of SK3530 in drug substance and tablet

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JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS 2007年第3期43卷 1179-1184页

作者： Oh, Joon Gyo Jang, Woo-Jae Chi, Sang-Cheol SK Chem Ltd Life Sci R&D Ctr Suwon 440745 Kyunggi Do South Korea Sungkyunkwan Univ Coll Pharm Suwon 440746 Kyunggi Do South Korea

SK3530.2HCl, (2-(5-(4-(2-hydroxyethyl)piperazin-1-ylsulfonyl)-2-n-propoxyphenyl)-5-ethyl-7-n-propyl-3,5-dihydro-4H-pyrrolo[3,2-d]pyrimidin-4-one dihydrochloride), is a novel a new phosphodiesterase type V (PDE V) inhibiting agents. The pharmaceutical development of SK3530 necessitated the availability of an assay for the quantification and purity determination of SK3530 active pharmaceutical ingredient (API) and its pharmaceutical dosage form. A reversed-phase high performance liquid chromatographic (HPLC) method with ultraviolet (UV) detection was developed, consisting of separation on a C18 column with a CapcellPack MG (4.6 mm x 150 mm, 5 mu m) column with ammonium acetate buffer (pH 4.0, 20 mM)-acetonitrile (60:40, v/v) as the isocratic mobile phase and UV detection at 250 nm. The method has been shown good chromatographic separation for SK3530 and the other related substances. The method was found to be linear 200-300 mu g/ml, precise and accurate. Stress testing showed degradation products, which were well separated from the parent compound, confirming its stability-indication capacity. Moreover, the use of LC-MS and on-line diode array detection enabled us to propose structures for degradation products. (c) 2006 Published by Elsevier B.V.

关键词： SK3530 HPLC degradation products mass spectrometry diode array detection

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Determination of propoxur residues in eggs by liquid chromatography-diode array detection after treatment of stocked housing facilities for the poultry red mite (Dermanyssus gallinae)

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ANALYTICA CHIMICA ACTA 2003年第1-2期483卷 19-26页

作者： Hamscher, G Priess, B Hartung, J Nogossek, MI Glünder, G Nau, H Sch Vet Med Ctr Food Sci Dept Food Toxicol D-30173 Hannover Germany Sch Vet Med Inst Anim Hyg & Anim Welfare D-30559 Hannover Germany Sch Vet Med Clin Poultry D-30559 Hannover Germany

A sensitive and selective liquid chromatography-diode array detection method for the determination of propoxur in eggs is described. Eggs were homogenized, extracted with acetonitrile and partitioned with n-hexane. Further clean-up of the acetonitrile extract was undertaken using silica gel column chromatography. Quantitative detection was performed by liquid chromatography with UV detection at 220 nm and confirmation of the residue was achieved via diode array detection (200-350 nm). Recovery rates (performed at the 5-100 mug kg(-1) level) were in the range 84.9-92.5% with relative standard deviations of 1.9-8.6%. The limit of detection of the assay based on a signal to noise ratio of 3 was approximately 2 mug kg(-1). The applicability of the method was demonstrated in eggs from laying hens kept in three different systems (i.e. battery cages, enriched cages and an aviary system). The henhouses were sprayed three times with CBM 8((R)) (containing propoxur in a final concentration of 1%). In this study, propoxur residues could be detected from day 1 after the first treatment until day 39. The mean residue concentration found in the eggs obtained from the battery cages was significantly higher (P < 0.05) than that of the enriched cages and the aviary system. In six eggs, residues above the actual maximal residue limits for eggs in the European Union (50 mug kg(-1)) were found. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： propoxur liquid chromatography diode array detection Dermanyssus gallinae laying hens

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Screening test to detect meat adulteration through the determination of hemoglobin by cation exchange chromatography with diode array detection

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MEAT SCIENCE 2003年第4期64卷 427-432页

作者： Wissiack, R de la Calle, B Bordin, G Rodriguez, AR Commiss European Communities Joint Res Ctr Inst Reference Mat & Measurements B-2440 Geel Belgium

A simple sample preparation procedure, consisting of an extraction step with Milli-Q water as extraction solvent for hemoglobins from meat samples, followed by a filtration step with a cellulose acetate filter, is applied. After cation exchange chromatographic separation and diode array detection, different peak patterns for extracted hemoglobins of cow, lamb or pork meat are obtained. Other heme-group containing proteins like myoglobin or cytochrome C, which could be also detected with diode array detection at 416 run, are chromatographically separated from the hemoglobins. By the use of these characteristic peak patterns, the species of the meat can be specified permitting the qualitative assessment of meat adulteration with the proposed screening method. (C) 2003 Elsevier Science Ltd. All rights reserved.

关键词： meat adulteration hemoglobin cation exchange chromatography diode array detection pork meat cow meat lamb meat

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Comparison of several curve resolution methods for drug impurity profiling using high-performance liquid chromatography with diode array detection

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ANALYTICA CHIMICA ACTA 2003年第2期487卷 155-170页

作者： van Zomeren, PV Darwinkel, H Coenegracht, PMJ de Jong, GJ Univ Groningen Dept Analyt Chem & Toxicol NL-9700 AD Groningen Netherlands

The performance of five curve resolution methods was compared systematically for the identification and quantification of impurities in drug impurity profiling. These methods are alternating least-squares (ALS) with either random or iterative key-set factor analysis (IKSFA) initialisation, iterative target transformation factor analysis (ITTFA), evolving factor analysis (EFA), and heuristic evolving latent projections (HELP). Real and simulated high-performance liquid chromatography diode array detection (HPLC-DAD) data were obtained for drug mixtures containing one main compound and two impurities. The elution order of the main compound and the impurities was varied. Furthermore, resolutions were varied from 0.56 to 3.36 and impurity levels from 30% down to 0.1%. For simulated data, ALS with IKSFA initialisation and HELP perform better than ITTFA and EFA, which perform better than ALS with random initialisation. ITTFA works better than EFA for almost completely separated data, while the opposite is true for moderately or strongly overlapping data. Only ALS with IKSFA initialisation and HELP were found to resolve the required 0.1% level for moderately overlapping data. For real data, comparison of the methods provides similar results. ITTFA performs clearly better than EFA. However, none of the curve resolution methods can identify or quantify impurities at the required 0.1% level. The results for real data are worse than for simulated data because of heteroscedasticity, nonlinearity, and the acquisition resolution of the A/D-converter. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： impurity profiling high-performance liquid chromatography diode array detection curve resolution

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Capillary zone electrophoresis in wide bore capillary tubes with fiber-coupled diode array detection

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JOURNAL OF CHROMATOGRAPHY A 2003年第1-2期990卷 23-33页

作者： Strasík, S Danková, M Molnárová, M Ölvecká, E Kaniansky, D Comenius Univ Fac Nat Sci Dept Analyt Chem SK-84215 Bratislava Slovakia

This feasibility study deals with the use of a wide bore (320 mum I.D.) capillary tube for the detection and identification of capillary zone electrophoresis (CZE) analytes by optical fiber-coupled diode array detection. A 250-mum mean effective pathlength of the detection cell with an inherently enhanced photon flux through the cell were significant contributors in reaching 0.2-1 mumol/l concentration detectabilities of the CZE analytes by this combination. Experiments with model analytes (p-sulfanilic, sorbic and naphthalene-2-sulfonic acids, tryptophan and asulam) revealed that spectral confirmations of their identities were still possible when their concentrations in the loaded samples (200 nl) were 1-5 mumol/l. Here, chemometry procedures (target transformation factor analysis, fixed size moving window-target transformation factor analysis, fixed size moving window-evolving factor analysis and orthogonal projection approach) employed in the data processing effectively contributed to reliable confirmation of the identities of the analytes also in critical situations (e.g. peak overlaps). The CZE separations were carried out in tandem-coupled columns of identical I.D. This made it possible to use, in the first column of the tandem, carrier electrolyte solutions that provide the desired separative effects, while in the second (detection) column the compositions of the carrier electrolyte solutions employed could reflect favorable conditions for obtaining spectral data. Mixtures containing model constituents at significantly differing concentrations and Maillard's reaction products spiked with tryptophan enantiomers were employed in experiments aimed at assessing practical applicabilities and limits of the present approach to the analysis of samples characterized by complex ionic matrices. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： diode array detection detection, electrophoresis chemometrics naphthalene-sulfonic acids asulam sorbic acid sulfanilic acid

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Capillary zone electrophoresis in wide bore capillary tubes with fiber-coupled diode array detection

Capillary zone electrophoresis in wide bore capillary tubes ...

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13th International Symposium on Capillary Electroseparation Techniques

作者： Strasík, S Danková, M Molnárová, M Ölvecká, E Kaniansky, D Comenius Univ Fac Nat Sci Dept Analyt Chem SK-84215 Bratislava Slovakia

关键词： diode array detection detection, electrophoresis chemometrics naphthalene-sulfonic acids asulam sorbic acid sulfanilic acid

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Analysis of three- and four-way data using multivariate curve resolution-alternating least squares with global multi-way kinetic fitting

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CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS 2006年第1期81卷 82-93页

作者： Bezemer, E Rutan, SC Virginia Commonwealth Univ Dept Chem Richmond VA 23284 USA

This paper demonstrates a novel implementation of an alternating least squares (ALS) algorithm for resolving three- and four-way data. Computer-simulated multi-way data are studied as well as the multi-way data obtained from typical kinetic experiments observed using liquid chromatography with diode array detection (LC-DAD) and UV-visible spectroscopy. Each data set is analyzed using this new multi-way ALS algorithm, not only providing estimates of the spectral profiles (and retention profiles in the case of LC-DAD measurements) for each of the components involved, but also simultaneously estimating the rate constants for the reaction steps at different experimental conditions using a global kinetic analysis. However, when the reaction conditions do not require that all the rate constants are identical for each experiment, as is the case when the reactions are observed at different temperatures, the data analysis still benefits from the common information present in the data, such as spectral and retention profiles, as well as a common reaction mechanism. (c) 2005 Elsevier B.V. All rights reserved.

关键词： kinetic constraint hydrolisis nonlinear regression liquid chromatography diode array detection

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