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Sample records for high resolution-liquid chromatography

  1. Characterization of Fumonisin A-Series by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

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    Masayoshi Tamura

    2014-08-01

    Full Text Available Fumonisin A-series (FAs in a reference material of corn sample that was naturally contaminated with fumonisins was characterized using high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitap MS. Peaks for fumonisin B1 (FB1, fumonisin B2 (FB2, and fumonisin B3 (FB3, in addition to three peaks corresponding to unknown compounds I, II, and III, were detected in the chromatogram for the corn sample. Fragment ion analysis for FB1, FB2, and FB3 showed that while the ions formed at m/z values of 200–800 were similar to those formed by the cleavage of the tricarballylic acids and the hydroxyl groups, the fragmentation patterns at m/z values of 50–200 varied depending on the hydroxyl group locations in the compounds. Fragment ion analysis of compounds I–III revealed structural similarities to FBs, only differing by an additional C2H2O in the unknown compounds. Using these results and by comparing the product ion mass spectra of compound I with fumonisin A1 (FA1 synthesized from FB1 standards, compounds I–III were hypothesized to be N-acetyl analogs of FBs: fumonisins A1 (FA1, A2 (FA2, and A3 (FA3. The method for determining concentrations was validated with FA1, FB1, FB2, and FB3 standards and applied to analyze the reference material. The FB1, FB2, and FB3 analytical levels were within acceptance limits and the amount of FA1 in the material was ~15% of FB1 amount at 4.2 mg/kg.

  2. A new approach to untargeted integration of high resolution liquid chromatography-mass spectrometry data.

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    van der Kloet, Frans M; Hendriks, Margriet; Hankemeier, Thomas; Reijmers, Theo

    2013-11-01

    Because of its high sensitivity and specificity, hyphenated mass spectrometry has become the predominant method to detect and quantify metabolites present in bio-samples relevant for all sorts of life science studies being executed. In contrast to targeted methods that are dedicated to specific features, global profiling acquisition methods allow new unspecific metabolites to be analyzed. The challenge with these so-called untargeted methods is the proper and automated extraction and integration of features that could be of relevance. We propose a new algorithm that enables untargeted integration of samples that are measured with high resolution liquid chromatography-mass spectrometry (LC-MS). In contrast to other approaches limited user interaction is needed allowing also less experienced users to integrate their data. The large amount of single features that are found within a sample is combined to a smaller list of, compound-related, grouped feature-sets representative for that sample. These feature-sets allow for easier interpretation and identification and as important, easier matching over samples. We show that the automatic obtained integration results for a set of known target metabolites match those generated with vendor software but that at least 10 times more feature-sets are extracted as well. We demonstrate our approach using high resolution LC-MS data acquired for 128 samples on a lipidomics platform. The data was also processed in a targeted manner (with a combination of automatic and manual integration) using vendor software for a set of 174 targets. As our untargeted extraction procedure is run per sample and per mass trace the implementation of it is scalable. Because of the generic approach, we envision that this data extraction lipids method will be used in a targeted as well as untargeted analysis of many different kinds of TOF-MS data, even CE- and GC-MS data or MRM. The Matlab package is available for download on request and efforts are

  3. A Rough Guide to Metabolite Identification Using High Resolution Liquid Chromatography Mass Spectrometry in Metabolomic Profiling in Metazoans

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    David G Watson

    2013-01-01

    Full Text Available Compound identification in mass spectrometry based metabolomics can be a problem but sometimes the problem seems to be presented in an over complicated way. The current review focuses on metazoans where the range of metabolites is more restricted than for example in plants. The focus is on liquid chromatography with high resolution mass spectrometry where it is proposed that most of the problems in compound identification relate to structural isomers rather than to isobaric compounds. Thus many of the problems faced relate to separation of isomers, which is usually required even if fragmentation is used to support structural identification. Many papers report the use of MS/MS or MS2 as an adjunct to the identification of known metabolites but there a few examples in metabolomics studies of metazoans of complete structure elucidation of novel metabolites or metabolites where no authentic standards are available for comparison.

  4. A method for simultaneous determination of 20 Fusarium toxins in cereals by high-resolution liquid chromatography-Orbitrap mass spectrometry with a pentafluorophenyl column.

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    Tamura, Masayoshi; Mochizuki, Naoki; Nagatomi, Yasushi; Harayama, Koichi; Toriba, Akira; Hayakawa, Kazuichi

    2015-05-14

    A high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS) method was developed for simultaneous determination of 20 Fusarium toxins (nivalenol, fusarenon-X, deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, HT-2 toxin, T-2 toxin, neosolaniol, diacetoxyscirpenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisin A1, fumonisin A2, fumonisin A3, zearalenone, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol) in cereals. The separation of 20 Fusarium toxins with good peak shapes was achieved using a pentafluorophenyl column, and Orbitrap MS was able to detect accurately from cereal matrix components within ±0.77 ppm. The samples were prepared using a QuEChERS kit for extraction and a multifunctional cartridge for purification. The linearity, repeatability, and recovery of the method were >0.9964, 0.8%-14.7%, and 71%-106%, respectively. Using this method, an analysis of 34 commercially available cereals detected the presence of deoxynivalenol, 15-acetyl deoxynivalenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisn A1, fumonisin A2, fumonisin A3, and zearalenone in corn samples with high concentration and frequency. Trichothecenes was detected from wheat samples with high frequency; in particular, the concentration of deoxynivalenol was high. Conversely, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol were not detected in any of the samples.

  5. A Method for Simultaneous Determination of 20 Fusarium Toxins in Cereals by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry with a Pentafluorophenyl Column

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    Masayoshi Tamura

    2015-05-01

    Full Text Available A high-resolution liquid chromatography-Orbitrap mass spectrometry (LC-Orbitrap MS method was developed for simultaneous determination of 20 Fusarium toxins (nivalenol, fusarenon-X, deoxynivalenol, 3-acetyl deoxynivalenol, 15-acetyl deoxynivalenol, HT-2 toxin, T-2 toxin, neosolaniol, diacetoxyscirpenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisin A1, fumonisin A2, fumonisin A3, zearalenone, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol in cereals. The separation of 20 Fusarium toxins with good peak shapes was achieved using a pentafluorophenyl column, and Orbitrap MS was able to detect accurately from cereal matrix components within ±0.77 ppm. The samples were prepared using a QuEChERS kit for extraction and a multifunctional cartridge for purification. The linearity, repeatability, and recovery of the method were >0.9964, 0.8%–14.7%, and 71%–106%, respectively. Using this method, an analysis of 34 commercially available cereals detected the presence of deoxynivalenol, 15-acetyl deoxynivalenol, fumonisin B1, fumonisin B2, fumonisin B3, fumonisn A1, fumonisin A2, fumonisin A3, and zearalenone in corn samples with high concentration and frequency. Trichothecenes was detected from wheat samples with high frequency; in particular, the concentration of deoxynivalenol was high. Conversely, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol were not detected in any of the samples.

  6. Detection of Type A Trichothecene Di-Glucosides Produced in Corn by High-Resolution Liquid Chromatography-Orbitrap Mass Spectrometry

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    Hitoshi Nagashima

    2013-03-01

    Full Text Available The existence of di-glucosylated derivative of T-2 toxin in plant (corn powder was confirmed for the first time in addition to that of HT-2 toxin. These masked mycotoxins (mycotoxin glucosides were identified as T-2 toxin-di-glucoside (T2GlcGlc and HT-2 toxin-di-glucoside (HT2GlcGlc based on accurate mass measurements of characteristic ions and fragmentation patterns using high-resolution liquid chromatography-Orbitrap mass spectrometric (LC-Orbitrap MS analysis. Although the absolute structure of T2GlcGlc was not clarified, two glucose molecules were suggested to be conjugated at 3-OH position in tandem when considering the structure of T-2 toxin. On the other hand, the specification of the structure seems to be more complicated in the case of HT2GlcGlc, since HT-2 toxin has two possible positions (at 3-OH and 4-OH to be glusocylated. In addition, 15-monoacetoxyscirpenol-glucoside (MASGlc was also detected in the identical sample.

  7. High-Resolution Liquid Chromatography Tandem Mass Spectrometry Enables Large Scale Molecular Characterization of Dissolved Organic Matter

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    Daniel Petras

    2017-12-01

    Full Text Available Dissolved organic matter (DOM is arguably one of the most complex exometabolomes on earth, and is comprised of thousands of compounds, that together contribute more than 600 × 1015 g carbon. This reservoir is primarily the product of interactions between the upper ocean's microbial food web, yet abiotic processes that occur over millennia have also modified many of its molecules. The compounds within this reservoir play important roles in determining the rate and extent of element exchange between inorganic reservoirs and the marine biosphere, while also mediating microbe-microbe interactions. As such, there has been a widespread effort to characterize DOM using high-resolution analytical methods including nuclear magnetic resonance spectroscopy (NMR and mass spectrometry (MS. To date, molecular information in DOM has been primarily obtained through calculated molecular formulas from exact mass. This approach has the advantage of being non-targeted, accessing the inherent complexity of DOM. Molecular structures are however still elusive and the most commonly used instruments are costly. More recently, tandem mass spectrometry has been employed to more precisely identify DOM components through comparison to library mass spectra. Here we describe a data acquisition and analysis workflow that expands the repertoire of high-resolution analytical approaches available to access the complexity of DOM molecules that are amenable to electrospray ionization (ESI MS. We couple liquid chromatographic separation with tandem MS (LC-MS/MS and a data analysis pipeline, that integrates peak extraction from extracted ion chromatograms (XIC, molecular formula calculation and molecular networking. This provides more precise structural characterization. Although only around 1% of detectable DOM compounds can be annotated through publicly available spectral libraries, community-wide participation in populating and annotating DOM datasets could rapidly increase the

  8. Multi-detection of corticosteroids in sports doping and veterinary control using high-resolution liquid chromatography/time-of-flight mass spectrometry

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    Touber, M.E.; Engelen, M.C.; Georgakopoulus, C.; Rhijn, van J.A.; Nielen, M.W.F.

    2007-01-01

    A liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) method was developed using the latest high-resolution LC column technology, the ultra performance liquid chromatography (UPLC (TM)), and electrospray ionization (ESI) in the positive ion mode. Gradient UPLC separation conditions

  9. Ultra-Sensitive, High-Resolution Liquid Chromatography Methods for the High-Throughput Quantitative Analysis of Bacterial Cell Wall Chemistry and Structure.

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    Alvarez, Laura; Hernandez, Sara B; de Pedro, Miguel A; Cava, Felipe

    2016-01-01

    High-performance liquid chromatography (HPLC) analysis has been critical for determining the structural and chemical complexity of the cell wall. However this method is very time consuming in terms of sample preparation and chromatographic separation. Here we describe (1) optimized methods for peptidoglycan isolation from both Gram-negative and Gram-positive bacteria that dramatically reduce the sample preparation time, and (2) the application of the fast and highly efficient ultra-performance liquid chromatography (UPLC) technology to muropeptide separation and quantification. The advances in both analytical instrumentation and stationary-phase chemistry have allowed for evolved protocols which cut run time from hours (2-3 h) to minutes (10-20 min), and sample demands by at least one order of magnitude. Furthermore, development of methods based on organic solvents permits in-line mass spectrometry (MS) of the UPLC-resolved muropeptides. Application of these technologies to high-throughput analysis will expedite the better understanding of the cell wall biology.

  10. Advances in organic polymer-based monolithic column technology for high-resolution liquid chromatography-mass spectrometry profiling of antibodies, intact proteins, oligonucleotides, and peptides.

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    Eeltink, Sebastiaan; Wouters, Sam; Dores-Sousa, José Luís; Svec, Frantisek

    2017-05-19

    This review focuses on the preparation of organic polymer-based monolithic stationary phases and their application in the separation of biomolecules, including antibodies, intact proteins and protein isoforms, oligonucleotides, and protein digests. Column and material properties, and the optimization of the macropore structure towards kinetic performance are also discussed. State-of-the-art liquid chromatography-mass spectrometry biomolecule separations are reviewed and practical aspects such as ion-pairing agent selection and carryover are presented. Finally, advances in comprehensive two-dimensional LC separations using monolithic columns, in particular ion-exchange×reversed-phase and reversed-phase×reversed-phase LC separations conducted at high and low pH, are shown. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Rapid and Efficient Desulfonation Method for the Analysis of Glucosinolates by High-Resolution Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry.

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    Singh, Jashbir; Jayaprakasha, Guddadarangavvanahally K; Patil, Bhimanagouda S

    2017-12-20

    The goal of our present research was to develop a simple and rapid method for the quantitation of desulfoglucosinolates (desulfoGLS) without using column chromatography. The proposed method involves extraction, concentration, incubation of glucosinolates with a sulfatase enzyme, and HPLC analysis. Identification of desulfoGLS in green kohlrabi was performed by LC-HR-ESI-QTOF-MS in positive-ionization mode. A total of 11 desulfoGLS were identified with neoglucobrassicin (3.32 ± 0.05 μmol/g DW) as the predominant indolyl, whereas progoitrin and sinigrin were the major aliphatic desulfoGLS. The levels of the aliphatic desulfoGLS glucoiberin, progoitrin, and glucoerucin at 7 h were found to be 3.6-, 1.9-, and 1.6-fold higher, respectively, than those produced through the conventional method. This technique was successfully applied in the identification of desulfoGLS from cabbage. The developed method has fewer unit operations, has maximum recovery, and is reproducible in the determination of desulfoGLS in a large number of Brassicaceae samples in a short time.

  12. Evaluation of the composition of vine shoots and oak chips for oenological purposes by superheated liquid extraction and high-resolution liquid chromatography-time-of-flight/mass spectrometry analysis.

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    Delgado de la Torre, M Pilar; Priego-Capote, Feliciano; Luque de Castro, María Dolores

    2012-04-04

    Vine shoots are characterized in this research and compared to oak chips, frequently employed in the aging of wine or spirits. For this purpose, liquid chromatography-diode array detection and liquid chromatography-time-of-flight/mass spectrometry (LC-TOF/MS) analyses of hydroalcoholic extracts from vine shoots pertaining to 18 different vine varieties and from five varieties of oak chips have been carried out. The concentrations of a representative panel of interesting compounds from an oenological point of view have been compared in the extracts, finding similarity patterns for many of them. The analysis by LC-TOF/MS in high accuracy mode has led to the identification of numerous compounds in the hydroalcoholic extracts. The statistical analysis has enabled identification of the vine-shoot varieties providing extracts with more similar composition to that given by extracts from oak chips. Therefore, these vine-shoots varieties are suitable to be presented as an alternative to the use of oak barrels or oak chips in the aging process of wine and spirits.

  13. Rapid resolution liquid chromatography (RRLC) analysis for quality control of Rhodiola rosea roots and commercial standardized products.

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    Ma, Yuan-Chun; Wang, Xiao-Qiang; Hou, Fei Fei; Ma, Jie; Luo, Mai; Lu, Shane; Jin, Peter; Terevsky, Nelly; Chen, Alice; Xu, Iris; Patel, Asmita V; Gorecki, Dariusz

    2011-05-01

    A simple, sensitive and reliable reversed phase Rapid Resolution Liquid Chromatography (RRLC) method was developed and validated for six biologically active compounds (salidroside, tyrosol, rosarin, rosavin, rosin and rosiridin) in Rhodiola rosea L. roots and powder extracts. The method uses a Phenomenex C18 (2)-HST column at 40 degrees C with a neutral gradient system mobile phase (H20 and acetonitrile), a flow rate of 1.0 mL/min, and UV detection wavelengths set at 205 and 254 nm, simultaneously. Baseline separation of the six active compounds was achieved within 8 minutes. The average percentages of rosavins (rosarin, rosavin, and rosin) in authentic R. rosea roots and root powder extracts were quantitatively determined and a characteristic R. rosea roots RRLC profile was established. The RRLC method is accurate and sensitive; in addition, it effectively increases the sample analysis throughput compared with conventional HPLC.

  14. Método analítico por cromatografía líquida de alta resolución para el estudio de estabilidad del jarabe de loratadina 0,1 % Analytical method by high resolution liquid chromatography for the stability study of loratidine syrup 0.1 %

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    Leonid Torres Amaro

    2007-04-01

    Full Text Available Se validó un método de cromatografía líquida de alta resolución para el estudio de estabilidad del jarabe de loratadina 0,1 %. La curva de calibración en el rango de 13,6 a 3,36 µg/mL fue lineal, con un coeficiente de correlación igual a 0,99975; la prueba estadística para el intercepto y la pendiente, no significativa. El recobrado obtenido resultó de 100,2 % en el rango de concentración estudiado, y las pruebas de Cochran y Student (t, no significativas. El coeficiente de variación en el estudio de repetibilidad fue igual a 0,41 % para 10 réplicas ensayadas, mientras que en la reproducibilidad las pruebas de Fischer y Student, no significativas. El método resultó específico, lineal, preciso y exacto.A high resolution liquid chromatography method was validated to study the stability of loratidine syrup 0.1 %. The calibration curve in the range from 13.6 to 3.36 µg/mL was lineal, with a coefficient of correlation equal to 0.99975. The intercept and slope statistical test was not significant. The recovery obtained was 100.2 % in the concentration range studied, and the Cochran and Student (t tests results were not important. The variation coefficient in the repeatability study was equal to 0.41 % for 10 replications assayed, whereas in the reproducibility Fischer and Student tests were not remarkable. The method proved to be specific, lineal, accurate, and exact.

  15. Método analítico por cromatografía líquida de alta resolución para la determinación de carbamazepina en plasma humano Analytical method by high resolution liquid chromatography for the determination of carbamazepine in human plasma

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    Narda M. Jiménez Alemán

    2007-04-01

    Full Text Available Entre los requisitos para desarrollar los estudios de biodisponibilidad y bioequivalencia se encuentra contar con metodologías analíticas validadas para el trabajo con muestras en fluidos biológicos. Se desarrolló un método por cromatografía líquida de alta resolución para la determinación de carbamazepina en plasma humano, se utilizó como fase móvil una mezcla de hidrógeno fosfato de sodio: acetonitrilo (65:35 ajustada a pH= 3,3 con ácido fosfórico, flujo de 1,2 mL/min y detección ultravioleta a 210 nm. Se empleó propilparabeno como estándar interno. Conforme con las regulaciones establecidas para la validación de métodos en fluidos biológicos se estudiaron los parámetros siguientes: estabilidad de las muestras, linealidad, especificidad, precisión, exactitud y límite de detección y cuantificación. El método resultó específico y sensible con un límite de detección y cuantificación de 0,9 y 1,0 ng, respectivamente. El método fue lineal, preciso y exacto en el rango de concentraciones de 1,07 a 12,67 µg/mL. La recuperación media no fue estadísticamente diferente del 100,0 %. El analito en la matriz biológica propuesta permaneció en el periodo estudiado. La metodología descrita en este trabajo se aplica en nuestro caso al estudio que evalúa la biodisponibilidad y bioequivalencia de una formulación cubana de carbamazepina en voluntarios sanos.One of the requirements to develop the studies of bioavailability and bioequivalence is to have analytic methodologies validated for the work with samples in biological fluids. A method was developed by high resolution liquid chromatography for the determination of carbamazepine in human plasma. A mixture of hydrogen phosphate of sodium: acetonitrile (65:35 adjusted to pH= 3.3 with phosphoric acid, flow of 1.2 mL/min and ultraviolet detection at 210 nm, was used as mobile phase. Propylparabene was used as an internal standard. According to the established regulations for

  16. Detection of Gelatin Adulteration in Traditional Chinese Medicine: Analysis of Deer-Horn Glue by Rapid-Resolution Liquid Chromatography-Triple Quadrupole Mass Spectrometry

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    Jia Chen

    2015-01-01

    Full Text Available Simultaneous identification of donkey-hide gelatin and bovine-hide gelatin in deer-horn glue was established by rapid-resolution liquid chromatography-triple quadrupole mass spectrometry. Water containing 1% NH4HCO3 was used for sample dissolution and trypsin was used for hydrolysis of the gelatins. After separation by a SB-C18 reversed-phase analytical column, collagen marker peptides were detected by mass spectrometry in positive electrospray ionization mode with multiple reaction monitoring. The method was specific, precise and reliable, and suitable for detection of adulterants derived from donkey-hide gelatin and bovine-hide gelatin in deer-horn glue.

  17. Sequential determination of fat- and water-soluble vitamins in Rhodiola imbricata root from trans-Himalaya with rapid resolution liquid chromatography/tandem mass spectrometry.

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    Tayade, Amol B; Dhar, Priyanka; Kumar, Jatinder; Sharma, Manu; Chaurasia, Om P; Srivastava, Ravi B

    2013-07-30

    A rapid method was developed to determine both types of vitamins in Rhodiola imbricata root for the accurate quantification of free vitamin forms. Rapid resolution liquid chromatography/tandem mass spectrometry (RRLC-MS/MS) with electrospray ionization (ESI) source operating in multiple reactions monitoring (MRM) mode was optimized for the sequential analysis of nine water-soluble vitamins (B1, B2, two B3 vitamins, B5, B6, B7, B9, and B12) and six fat-soluble vitamins (A, E, D2, D3, K1, and K2). Both types of vitamins were separated by ion-suppression reversed-phase liquid chromatography with gradient elution within 30 min and detected in positive ion mode. Deviations in the intra- and inter-day precision were always below 0.6% and 0.3% for recoveries and retention time. Intra- and inter-day relative standard deviation (RSD) values of retention time for water- and fat-soluble vitamin were ranged between 0.02-0.20% and 0.01-0.15%, respectively. The mean recoveries were ranged between 88.95 and 107.07%. Sensitivity and specificity of this method allowed the limits of detection (LOD) and limits of quantitation (LOQ) of the analytes at ppb levels. The linear range was achieved for fat- and water-soluble vitamins at 100-1000 ppb and 10-100 ppb. Vitamin B-complex and vitamin E were detected as the principle vitamins in the root of this adaptogen which would be of great interest to develop novel foods from the Indian trans-Himalaya. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Rapid confirmatory analysis of non-steroidal anti-inflammatory drugs in bovine milk by rapid resolution liquid chromatography tandem mass spectrometry.

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    Dowling, Geraldine; Gallo, Pasquale; Malone, Edward; Regan, Liam

    2009-11-13

    A rapid method has been developed to analyse carprofen (CPF), diclofenac (DCF), mefenamic acid (MFN), niflumic acid (NIFLU), naproxen (NAP), oxyphenylbutazone (OXYPHEN), phenylbutazone (PBZ) and suxibuzone (SUXI) residues in bovine milk. Milk samples are extracted with acetonitrile and sample extracts were purified on Evolute ABN solid phase extraction cartridges. Aliquots were analysed by rapid resolution liquid chromatography tandem mass spectrometry (RRLC-MS/MS) with a runtime of 6.5 min. The method was validated in bovine milk, according to the criteria defined in Commission Decision 2002/657/EC. CCalpha values of 0.46, 1.08, 0.92, 1.26, 1.29, 2.12, 0.55 and 2.86 ng mL(-1) were determined for CPF, DCF, MFN, NIFLU, NAP, OXYPHEN, PBZ and SUXI, respectively. CCbeta values of 0.79, 1.85, 1.56, 2.15, 2.19, 3.62, 0.94 and 4.87 ng mL(-1) were determined for CPF, DCF, MFN, NIFLU, NAP, OXYPHEN, PBZ and SUXI, respectively. The measurement uncertainty of the method was estimated at 9, 28, 28, 45, 46, 45, 10 and 39% for CPF, DCF, MFN, NIFLU, NAP, OXYPHEN, PBZ and SUXI. Fortifying bovine milk samples (n=18) in three separate assays, show the accuracy of the method to be between 82 and 108%. The precision of the method, expressed as RSD values for the within-lab reproducibility at the three levels of fortification (5, 7.5 and 10 ng mL(-1)) was less than 16%, respectively. The advantage of the method is that low ng mL(-1) levels can be detected and quantitatively confirmed rapidly in milk and that 3 batches of samples can be analysed within a single day using RRLC-MS/MS with a runtime of 6.5 min.

  19. Aberration production using a high-resolution liquid-crystal spatial light modulator.

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    Schmidt, Jason D; Goda, Matthew E; Duncan, Bradley D

    2007-05-01

    Phase-only liquid-crystal spatial light modulators provide a powerful means of wavefront control. With high resolution and diffractive (modulo 2pi) operation, they can accurately represent large-dynamic-range phase maps. As a result, they provide an excellent means of producing electrically controllable, dynamic, and repeatable aberrations. However, proper calibration is critical to achieving accurate phase maps. Several calibration methods from previous literature were considered. With simplicity and accuracy in mind, we selected one method for each type of necessary calibration. We augmented one of the selected methods with a new step that improves its accuracy. After calibrating our spatial light modulator with our preferred methods, we evaluated its ability to produce aberrations in the laboratory. We studied Zernike polynomial aberrations using interferometry and Fourier-transform-plane images, and atmospheric aberrations using a Shack-Hartmann wavefront sensor. These measurements show the closest agreement with theoretical expectations that we have seen to date.

  20. Integrated rapid resolution liquid chromatography-tandem mass spectrometric approach for screening and identification of metabolites of the potential anticancer agent 3,6,7-trimethoxyphenanthroindolizidine in rat urine.

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    Tian, Yaping; He, Jiuming; Zhang, Ruiping; Lv, Haining; Ma, Shuanggang; Chen, Yanhua; Yu, Shishan; Chen, Xiaoguang; Wu, Yan; He, Wenyi; Abliz, Zeper

    2012-06-20

    An integrated approach combining data acquisition using MS(E) and multi-period product ion scan (mpMS/MS), with high-resolution characteristic extracted ion chromatograms (hcXIC) as a data mining method, was developed for in vivo drug metabolites screening and identification. This approach is illustrated by analyzing metabolites of a potential anticancer agent, 3,6,7-trimethoxyphenanthroindolizidine (CAT) in rat urine based on rapid resolution liquid chromatography combined with tandem mass spectrometry (RRLC-MS/MS). Untargeted full-scan MS(E) enabled the high-throughput acquisition of potential metabolites, and targeted mpMS/MS contributed to the sensitivity and specificity of the acquisition of molecules of interest. The data processing method hcXIC, based on the structure of CAT, was shown to be highly effective for the metabolite discovery. Through the double-filtering effect of the characteristic ion and accurate mass, conventional extracted ion chromatograms that contained a substantial number of false-positive peaks were simplified into chromatograms essentially free of endogenous interferences. As a result, 21 metabolites were detected in rat urine after oral administration of CAT. Based on the characteristic fragmentation patterns of the phenanthroindolizidine alkaloid, the structures of 9 metabolites were identified. Furthermore, the interpretation of the MS/MS spectra of these metabolites enabled the determination of demethylation position as well as the differentiation between N-oxidized and hydroxylated metabolites. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Determination of veterinary penicillin antibiotics by fast high-resolution liquid chromatography and luminescence detection.

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    Castillo-García, M L; Aguilar-Caballos, M P; Gómez-Hens, A

    2017-08-01

    A chromatographic method based on the use of a fused-core column and luminescence detection is described for the determination of six penicillin antibiotics used in veterinary practice, namely amoxicillin, ampicillin, penicillin G, oxacillin, cloxacillin and nafcillin. The use of this column provides the separation of these antibiotics with retention times lower than 4.5min. The tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)3(2+)] - Ce(IV) system has been used as post-column derivatization reagent, obtaining a luminescence signal (λem 610nm) proportional to the analyte concentration when the system is excited at 450nm. The dynamic ranges of the calibration graphs are 100-10,000ngmL(-1) for all the antibiotics assayed and the limits of detection are in the range of 44-51ngmL(-1). The precision, established at two concentration levels of each analyte and expressed as the percentage of the relative standard deviation is in the range of 6.9-9.8%. The method has been satisfactorily applied to the analysis of water and pharmaceutical samples, with recoveries ranging from 88.6% to 108.5%. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The Profiling and Identification of the Absorbed Constituents and Metabolites of Guizhi Decoction in Rat Plasma and Urine by Rapid Resolution Liquid Chromatography Combined with Quadrupole-Time-of-Flight Mass Spectrometry

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    Hongjun Xiang

    2016-09-01

    Full Text Available Guizhi decoction (GZD, a well-known traditional Chinese medicine (TCM prescription consisting of Ramulus Cinnamomi, Radix Paeoniae Alba, Radix Glycyrrhizae, Fructus Jujubae and Rhizoma Zingiberis Recens, is usually used for the treatment of common colds, influenza, and other pyretic conditions in the clinic. However, the absorbed ingredients and metabolic compounds of GZD have not been reported. In this paper, a method incorporating rapid resolution liquid chromatography (RRLC with quadrupole-time-of-flight mass spectrometry (Q-TOF-MS was used to identify ingredients after oral administration of GZD. Identification of the primary components in GZD, drug-containing serum and urine samples was carried out in order to investigate the assimilation and metabolites of the decoction in vivo. By comparing the total ion chromatograms (TICs of GZD, a total of 71 constituents were detected or characterized. By comparing TICs of blank and dosed rat plasma, a total of 15 constituents were detected and identified as prototypes according to their retention time (tR and MS, MS/MS data. Based on this, neutral loss scans of 80 and 176 Da in samples of rat plasma and urine helped us to identify most of the metabolites. Results showed that the predominant metabolic pathways of (epi catechin and gallic acid were sulfation, methylation, glucuronidation and dehydroxylation; the major metabolic pathways of flavone were hydrolysis, sulfation and glucuronidation. Furthermore, degradation, oxidation and ring fission were found to often occur in the metabolism process of GZD in vivo.

  3. Preconcentration and sensitive determination of hexabromocyclododecane diastereomers in environmental water samples using solid phase extraction with bamboo charcoal cartridge prior to rapid resolution liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Zhao, Ru-Song; Hu, Cong; Zhou, Jia-Bin; Yuan, Jin-Peng; Wang, Shan-Shan; Wang, Xia

    2011-05-01

    In this paper, a simple and cheap method for the simultaneous preconcentration and sensitive determination of three hexabromocyclododecane (HBCD) diastereomers (α-, β-, and γ-HBCD) in environmental water samples has been developed. It was based on solid phase extraction (SPE) and rapid resolution liquid chromatography-electrospray tandem mass spectrometry. Bamboo charcoal, one kind of cheap material, was investigated and used as SPE adsorbent for the enrichment and determination of HBCD diastereomers. Related important parameters affecting extraction efficiencies, including type and volume of eluant, amount of sorbent, sample pH, flow rate, and sample volume, were investigated and optimized in detail. Under the optimum conditions, experimental data exhibited excellent linear relationships between peak area and concentrations over the range 0.1-10 μg L(-1). The limits of detection and precision were in the range of 0.005-0.015 μg L(-1) and 4.59-7.47%, respectively. The proposed method has been successfully applied for the trace analysis of HBCD diastereomers in real-world environmental water samples.

  4. High Performance Liquid Chromatography

    Science.gov (United States)

    Talcott, Stephen

    High performance liquid chromatography (HPLC) has many applications in food chemistry. Food components that have been analyzed with HPLC include organic acids, vitamins, amino acids, sugars, nitrosamines, certain pesticides, metabolites, fatty acids, aflatoxins, pigments, and certain food additives. Unlike gas chromatography, it is not necessary for the compound being analyzed to be volatile. It is necessary, however, for the compounds to have some solubility in the mobile phase. It is important that the solubilized samples for injection be free from all particulate matter, so centrifugation and filtration are common procedures. Also, solid-phase extraction is used commonly in sample preparation to remove interfering compounds from the sample matrix prior to HPLC analysis.

  5. High Performance Liquid Chromatography Method for the ...

    African Journals Online (AJOL)

    chromatography (HPLC) technique with UV-VIS detection method was developed for the determination of the compound in rat ... Keywords: Anethole, High performance liguid chromatography, Star anise, Essential oil, Rat plasma,. Illicium verum Hook. .... solution of anethole. Plasma proteins were precipitated by adding 0.3.

  6. High Performance Liquid Chromatography Method for the ...

    African Journals Online (AJOL)

    High Performance Liquid Chromatography Method for the Determination of Anethole in Rat Plasma. ... Journal Home > Vol 13, No 5 (2014) > ... Results: GC determination showed that anethole in the essential oil of star anise exhibited a ...

  7. determined by high perforiviance liquid chromatography

    African Journals Online (AJOL)

    ABSTRACT. The loss oi" L-ascorbic acid (L-AA) in 14 different cooketi local vegetables found in. Nairobi markets was determined by high performance liquid chromatography. The efifect of quantity of water on the loss of L-AA during cooking was studied with cowpea leaves. It, was found that more. L~AA was lost when ...

  8. Gradient High Performance Liquid Chromatography Method ...

    African Journals Online (AJOL)

    Purpose: To develop a gradient high performance liquid chromatography (HPLC) method for the simultaneous determination of phenylephrine (PHE) and ibuprofen (IBU) in solid dosage form. Methods: HPLC determination was carried out on an Agilent XDB C-18 column (4.6 x 150mm, 5 μ particle size) with a gradient ...

  9. Chromatography

    Science.gov (United States)

    ... that are bonded together. For example, water is a chemical bond of oxygen and hydrogen. Proteins are another type of chemical compound. There are different kinds of chromatography. These include gas, high pressure liquid, or ion ...

  10. Protein A chromatography at high titers.

    Science.gov (United States)

    Natarajan, Venkatesh; Zydney, Andrew L

    2013-09-01

    The large increase in antibody titers over the past two decades has created significant challenges for downstream processes; however, there have been no quantitative studies of the effect of feed concentration on the dynamic binding capacity in Protein A chromatography. Small scale experiments were performed using pre-packed ProSep® Ultra Plus columns over a range of feed flow rates and antibody concentrations. The data clearly demonstrate that the dynamic binding capacity decreases with increasing concentration of the monoclonal antibody at short residence times. This reduction in DBC is due to non-equilibrium mass transfer effects in the porous resin, with the experimental results consistent with predictions of a simple mathematical model based on a linear driving force with solid phase diffusion. These results provide important insights into the behavior of Protein A chromatography and provide a framework for the proper design of Protein A capture steps for high titer products. Copyright © 2013 Wiley Periodicals, Inc.

  11. Chromatography.

    Science.gov (United States)

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities on chromatography. Directions for preparing leaf pigment extracts using alcohol are given, and paper chromatography and thin-layer chromatography are described as modifications of the basic principles of chromatography. (KHR)

  12. Comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones.

    Science.gov (United States)

    Carnes, Stephanie; O'Brien, Stacey; Szewczak, Angelica; Tremeau-Cayel, Lauriane; Rowe, Walter F; McCord, Bruce; Lurie, Ira S

    2017-09-01

    A comparison of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography for the separation of synthetic cathinones has been conducted. Nine different mixtures of bath salts were analyzed in this study. The three different chromatographic techniques were examined using a general set of controlled synthetic cathinones as well as a variety of other synthetic cathinones that exist as positional isomers. Overall 35 different synthetic cathinones were analyzed. A variety of column types and chromatographic modes were examined for developing each separation. For the ultra high performance supercritical fluid chromatography separations, analyses were performed using a series of Torus and Trefoil columns with either ammonium formate or ammonium hydroxide as additives, and methanol, ethanol or isopropanol organic solvents as modifiers. Ultra high performance liquid chromatographic separations were performed in both reversed phase and hydrophilic interaction chromatographic modes using SPP C18 and SPP HILIC columns. Gas chromatography separations were performed using an Elite-5MS capillary column. The orthogonality of ultra high performance supercritical fluid chromatography, ultra high performance liquid chromatography, and gas chromatography was examined using principal component analysis. For the best overall separation of synthetic cathinones, the use of ultra high performance supercritical fluid chromatography in combination with gas chromatography is recommended. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Trends in High Performance Liquid Chromatography for Cultural Heritage.

    Science.gov (United States)

    Degano, Ilaria; La Nasa, Jacopo

    2016-04-01

    The separation, detection and quantitation of specific species contained in a sample in the field of Cultural Heritage requires selective, sensitive and reliable methods. Procedures based on liquid chromatography fulfil these requirements and offer a wide range of applicability in terms of analyte types and concentration range. The main applications of High Performance Liquid Chromatography in this field are related to the separation and detection of dyestuffs in archaeological materials and paint samples by reversed-phase liquid chromatography with suitable detectors. The relevant literature will be revised, with particular attention to sample treatment strategies and future developments. Reversed phase chromatography has also recently gained increasing importance in the analysis of lipid binders and lipid materials in archaeological residues: the main advantages and disadvantages of the new approaches will be discussed. Finally, the main applications of ion chromatography and size exclusion chromatography in the field of Cultural Heritage will be revised in this chapter.

  14. Porphyrins profile by high performance liquid chromatography ...

    African Journals Online (AJOL)

    Most porphyria symptoms are nonspecific and occur intermittently; resulting frequently in missed diagnosis since the disease itself is a rare one. The aim of the study is to establish a new reliable and accurate laboratory method for separation, identification and quantitation of urinary porphyrins by liquid chromatography ...

  15. ANALYSIS OF AMINO ACIDS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    Qurat E Noor Baig

    2016-06-01

    Full Text Available Amino acids are the building blocks of proteins and are considered as the key precursors for the formation of hormones and low molecular weight nitrogenous substances with biological importance. Since the analysis of amino acids has been carried out for both qualitative and quantitative purposes with an aim to study their levels in the plasma concentration, the quantitative determination, in particular, also helps in the diagnosis of different diseases associated with their deficiency. This review article deals with the determination of amino acids by chromatographic methods which include ion-exchange chromatography (IEC, high performance liquid chromatography (HPLC, reverse phase-high performance liquid chromatography (RP-HPLC and ultra-performance liquid chromatography (UPLC. The review will also give an idea for the preparation of samples, derivatization methods for the analysis of amino acids (direct and indirect methods and separation of amino acids by high performance liquid chromatographic technique.

  16. Analysis of Tocopherols by High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    B. Edison

    2009-01-01

    Full Text Available : Gas chromatography is the key technique for organic components and also for tocopherols analysis. High performance liquid chromatography has an important role to take part in applications such as the handling of less usual samples, prevention of degradation of heat sensitive functional groups and for micro preparative purposes. Many approaches for development of improved methods are suggested, especially for reversed phase applications.

  17. Development of High Performance Thin Layer Chromatography for ...

    African Journals Online (AJOL)

    and validation, a high performance thin layer chromatography (HPTLC) system with WinCATS software was used. Freshly prepared ... recommended in routine analysis of pharmaceutical products containing lamivudine and tenofovir disoproxil fumarate. Introduction ... A strong system of quality control and quality assurance ...

  18. The high performance liquid chromatography (HPLC) analysis of ...

    African Journals Online (AJOL)

    The high performance liquid chromatography (HPLC) analysis of ultraviolet (UV) irradiated chlorophyll a and secondary plant compounds. ... in all the samples leaving a bleached extract suitable for biological assays. Key words: Chlorophyll a, UV radiation, activated charcoal, HPLC, secondary compounds in plant extracts.

  19. Quantification of Tea Flavonoids by High Performance Liquid Chromatography

    Science.gov (United States)

    Freeman, Jessica D.; Niemeyer, Emily D.

    2008-01-01

    We have developed a laboratory experiment that uses high performance liquid chromatography (HPLC) to quantify flavonoid levels in a variety of commercial teas. Specifically, this experiment analyzes a group of flavonoids known as catechins, plant-derived polyphenolic compounds commonly found in many foods and beverages, including green and black…

  20. An optimized gossypol high-performance liquid chromatography ...

    Indian Academy of Sciences (India)

    A comparative study on gossypol content of various genetic types of pigment glands of cotton varieties was conducted through an optimized high-performance liquid chromatography (HPLC) on a C18 column (4.6 mm × 250 mm, 5 m particle) with methanol–0.5% acetic acid aqueous solution, 90 : 10 (v/v), as mobile phase, ...

  1. Enantioselective high performance liquid chromatography and supercritical fluid chromatography separation of spirocyclic terpenoid flavor compounds.

    Science.gov (United States)

    Schaffrath, Mathias; Weidmann, Verena; Maison, Wolfgang

    2014-10-10

    Chiral spirocyclic terpenoids are abundant natural flavors with significant impact particularly on the food industry. Chromatographic methods for analytical and preparative separation of these compounds are therefore of high interest to natural product chemists in academia and industry. Gas chromatography on chiral stationary phases is currently the standard method for the separation of volatile terpenoids, limiting the scale to analytical quantities. We report herein high performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC) protocols for the chiral separation of several racemic spirocyclic terpenoids such as the important flavors theaspirane and vitispirane. A screening of mobile phases and 16 commercially available chiral stationary phases (CSPs) largely based on polysaccharides led to identification of protocols for the separation of all terpenoids tested. SFC methods were found to be particularly useful for the separation of these spirocyclic flavors due to the volatility and low polarity of the compounds. The reported chiral HPLC and SFC protocols are scalable alternatives to gas chromatographic separations of volatile terpenoid flavors. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. 21 CFR 862.2260 - High pressure liquid chromatography system for clinical use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false High pressure liquid chromatography system for... Clinical Laboratory Instruments § 862.2260 High pressure liquid chromatography system for clinical use. (a) Identification. A high pressure liquid chromatography system for clinical use is a device intended to separate...

  3. Separation of human tear proteins by high performance liquid chromatography.

    Science.gov (United States)

    Boonstra, A; Kijlstra, A

    1984-12-01

    The optimal conditions for separating human tear proteins by high performance liquid chromatography (HPLC) using a Waters I-125 gel filtration column were investigated. Several elution buffers were tested including phosphate buffer alone and phosphate buffer to which varying amounts of NaCl or 0.1% Tween was added. The combination of phosphate buffer (pH 5.28), 0.5 M NaCl and 0.1% Tween gave the best resolution and a recovery of 90% of the proteins applied. Tear lactoferrin was shown to adhere to the column packing when the molarity of the elution buffer was not high enough. Using optimal conditions, the tear proteins IgA, lactoferrin and lysozyme were identified in distinct peaks after a preparative HPLC run. When used in combination with Schirmer strips as a tear sampling method, HPLC was shown to be a rapid, simple and reproducible way of investigating the composition of tear proteins.

  4. Analysis of 'ARN' naphthenic acids by high temperature gas chromatography and high performance liquid chromatography.

    Science.gov (United States)

    Smith, Ben E; Sutton, Paul A; Lewis, C Anthony; Dunsmore, Braden; Fowler, Geoffrey; Krane, Jostein; Lutnaes, Bjart F; Brandal, Øystein; Sjöblom, Johan; Rowland, Steven J

    2007-02-01

    Examination by high temperature GC (HTGC) of the methyl esters of the so-called 'ARN' naphthenic acids from crude oils of North Sea UK, Norwegian Sea and West African oilfields revealed the distributions of resolved 4-8 ring C80 tetra acids and trace amounts of other acids. Whilst all three oils contained apparently the same major acids, the proportions of each differed, possibly reflecting the growth temperatures of the archaebacteria from which the acids are assumed to have originated. The structures of the 4, 5, 7 and 8 ring acids are tentatively assigned by comparison with the known 6 ring acid and related natural products and an HPLC method for the isolation of the individual acids is described. ESI-MS of individual acids isolated by preparative HPLC established the elution order of the 4-8 ring acids on the HPLC and HTGC systems and revealed the presence of previously unreported acids tentatively identified as C81 and C82 7 and 8 ring analogues.

  5. Alcoholic fermentation process control by high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Morawski, J.; Dincer, A.K.; Ivie, K.

    1983-02-01

    In large-scale fermentation for energy production high-performance liquid chromatography (HPLC) provides an accurate method of monitoring the original oligosaccharides and polysaccharides, as well as their hydrolysis to fermentable monosaccharides. Also measuring the saccharide and alcohol content of the fermentation vat allows overseeing of the process, providing the capability of allowing the fermentation to proceed to the most economical level prior to distillation. Another application for HPLC in a large-scale fermentation for energy is to analyze the stillage for its ethanol content during distillation, in order to observe the efficiency of the still. HPLC can separate and detect very low levels, (i.e., 100 parts per million), of ethanol to yield information concerning the distillation process. These capabilities indicate that HPLC is an extremely useful efficient instrument to the fermentation industries. (Refs. 2).

  6. Towards Chip Scale Liquid Chromatography and High Throughput Immunosensing

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Jing [Iowa State Univ., Ames, IA (United States)

    2000-09-21

    This work describes several research projects aimed towards developing new instruments and novel methods for high throughput chemical and biological analysis. Approaches are taken in two directions. The first direction takes advantage of well-established semiconductor fabrication techniques and applies them to miniaturize instruments that are workhorses in analytical laboratories. Specifically, the first part of this work focused on the development of micropumps and microvalves for controlled fluid delivery. The mechanism of these micropumps and microvalves relies on the electrochemically-induced surface tension change at a mercury/electrolyte interface. A miniaturized flow injection analysis device was integrated and flow injection analyses were demonstrated. In the second part of this work, microfluidic chips were also designed, fabricated, and tested. Separations of two fluorescent dyes were demonstrated in microfabricated channels, based on an open-tubular liquid chromatography (OT LC) or an electrochemically-modulated liquid chromatography (EMLC) format. A reduction in instrument size can potentially increase analysis speed, and allow exceedingly small amounts of sample to be analyzed under diverse separation conditions. The second direction explores the surface enhanced Raman spectroscopy (SERS) as a signal transduction method for immunoassay analysis. It takes advantage of the improved detection sensitivity as a result of surface enhancement on colloidal gold, the narrow width of Raman band, and the stability of Raman scattering signals to distinguish several different species simultaneously without exploiting spatially-separated addresses on a biochip. By labeling gold nanoparticles with different Raman reporters in conjunction with different detection antibodies, a simultaneous detection of a dual-analyte immunoassay was demonstrated. Using this scheme for quantitative analysis was also studied and preliminary dose-response curves from an immunoassay of a

  7. Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Xikai; Wang, Mei; Liu, Daicheng [College of Life Science, Shandong Normal University, Jinan, Shandong (China); Wang, Daijie; Lin, Xiaojing; Liu, Jianhua; Wang, Xiao; Huang, Luqi, E-mail: wxjn1998@126.com [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China)

    2013-09-01

    An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-{beta}-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-{beta}-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). (author)

  8. Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Xikai Shu

    2013-01-01

    Full Text Available An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I, 24.5 mg of luteolin-7-O-β-D-rutinoside (compound II, 18.4 mg of luteolin-7-O-β-D-glucoside (compound III, and 33.4 mg of cynarin (compound IV with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS and nuclear magnetic resonance (NMR.

  9. Determination of saffron quality by high-performance liquid chromatography.

    Science.gov (United States)

    Valle García-Rodríguez, M; Serrano-Díaz, Jéssica; Tarantilis, Petros A; López-Córcoles, Horacio; Carmona, Manuel; Alonso, Gonzalo L

    2014-08-13

    The aim of this work was to propose a high-performance liquid chromatography with diode array detection (HPLC-DAD) method for determining the three main compounds responsible for determining the quality of saffron (crocetin esters, picrocrocin, and safranal) by preparing an aqueous extract according to the ISO 3632 standard to solve the difficulty that this standard has for aroma and taste determination by ultraviolet-visible spectroscopy. Toward this aim, laboratory-isolated picrocrocin, a safranal standard with a purity of ≥ 88%, trans-crocetin di(β-D-gentiobiosyl) ester (trans-4-GG) and trans-crocetin (β-D-glucosyl)-(β-D-gentiobiosyl) ester (trans-3-Gg) standards, both with a purity of ≥ 99%, and 50 different saffron spice samples from Italy, Iran, Greece, and Spain were used in the intralaboratory validation of the HPLC method. The analytical method proposed was adequate in terms of linearity, selectivity, sensitivity, and accuracy for determining the three foremost parameters that define the quality of saffron using only a saffron solution prepared according to the ISO 3632 standard.

  10. Spiral Tube Assembly for High-Speed Countercurrent Chromatography

    Science.gov (United States)

    Ito, Y.; Clary, R.; Powell, J.; Knight, M.; Finn, T. M.

    2009-01-01

    Optimal elution modes were determined for four typical two-phase solvent systems each with different physical parameters to achieve the best peak resolution and retention of the stationary phase by spiral tube high-speed countercurrent chromatography using a suitable set of test samples. Both retention of the stationary phase and partition efficiency are governed by an interplay between two forces, i.e., Archimedean Screw force and radial centrifugal force gradient of the spiral channel. In the polar solvent system represented by 1-butanol./acetic acid/water (4:1:5, v/v/v) with settling time of over 30 s, the effect by the radial centrifugal gradient force dominates giving the best separation of dipeptides either by pumping the lower phase from the inner terminal or the upper phase from the outer terminal of the spiral channel. In the moderately hydrophobic two-phase solvent system represented by hexane/ethyl acetate/methanol/0.1 M HCl (1:1:1:1) with settling time of 19 s, and two hydrophobic solvent systems of hexane/ethanol/water (5:4:1, v/v/v) and non-aqueous binary system of hexane/acetonitrile both having settling time of 9, the effect of the Archimedean screw force play a major role in hydrodynamic equilibrium, giving the best separations by pumping the lower phase from the head or the upper phase from the tail of the spiral channel. PMID:19343107

  11. High pH reversed-phase chromatography with fraction concatenation as an alternative to strong-cation exchange chromatography for two-dimensional proteomic analysis

    OpenAIRE

    Yang, Feng; Shen, Yufeng; Camp, David G.; Smith, Richard D.

    2012-01-01

    Orthogonal high-resolution separations are critical for attaining improved analytical dynamic range and protein coverage in proteomic measurements. High pH reversed-phase liquid chromatography (RPLC) followed by fraction concatenation affords better peptide analysis than conventional strong-cation exchange (SCX) chromatography applied for the two-dimensional proteomic analysis. For example, concatenated high pH reversed-phase liquid chromatography increased identification for peptides (1.8-fo...

  12. [Preparative separation of aloin diastereoisomers by high-speed countercurrent chromatography combined with silica gel column chromatography].

    Science.gov (United States)

    Huang, Danfeng; Cao, Xueli; Zhao, Hua; Dong, Yinmao

    2006-01-01

    Aloin, naturally a mixture of two diastereoisomers, aloin A and aloin B, is the major anthraquinone in aloe, and now served as one of the important control constituents in most of the commercial aloe products. High-speed countercurrent chromatography (HSCCC) combined with silica gel column chromatography was developed for the preparative separation of the two individual aloins. Aloin A (98%) and aloin B (96%) were obtained. Fast atom bombardment mass spectrometry (FAB-MS), 1H nuclear magnetic resonance (1H NMR) and GOESY (gradient-enhanced nuclear Overhauser effect spectroscopy) were employed for the elucidation of their structure conformation. The developed method is of high preparative capacity and high efficiency in resolution.

  13. Comparison of micellar electrokinetic capillary chromatography and high performance liquid chromatography on fingerprint of Cnidium monnieri.

    Science.gov (United States)

    Zhao, Luhua; Zhang, Xinyong; Tan, Xiying; Wu, Menghua; Xianga, Bingren

    2006-06-01

    In our studies, micellar electrokinetic capillary chromatography (MEKC) was employed in fingerprint analysis of Cnidium monnieri for the first time. Average chromatography of 10 batches Cnidium monnieri from Jiangsu province, China, which have long been considered as the original and genuine herbal medicine, was first established as the characteristic fingerprint. Within 25 min the major effective components were separated by 18 mM borate, 12 mM phosphate and 50 mM SDS (pH 9.2) containing 20% methanol. The relative standard deviations of migration times and peak areas were less than 5%. As a new approach of fingerprint, MKCE was compared to the conventional approach-HPLC in our experiments. The fingerprint developed by HPLC comprised 8 peaks that were collected within 40 min. Relative standard deviation (RSD) values of retention times of corresponding peaks in HPLC analysis were very small (maximum 3% and average 0.9%). In conclusion, each two methods had its advantages and disadvantages. Furthermore, besides HPLC, MEKC as a feasible method, could be used in the development of fingerprint of Cnidium monnieri.

  14. High Performance Liquid Chromatography-Diode Array Detector Method for the Simultaneous Determination of Five Compounds in the Pulp and Seed of Sea Buckthorn.

    Science.gov (United States)

    Zhao, Lu; Wen, E; Upur, Halmuart; Tian, Shuge

    2017-01-01

    Sea buckthorn ( Hippophae rhamnoides L.) as a traditional Chinese medicinal plant has various uses in Xinjiang. A reversed-phase rapid-resolution liquid-chromatography method with diode array detector was developed for simultaneous determination of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the pulp and seed of sea buckthorn, a widely used traditional Chinese medicine for promoting metabolism and treating scurvy and other diseases. Compounds were separated on an Agilent ZORBAX SB-C18 column (4.6 mm × 250 mm, 5 μm; USA) with gradient elution using methanol and 0.4% phosphoric acid (v/v) at 1.0 mL/min. Detection wavelength was set at 280 nm. The fruits of wild sea buckthorn were collected from Wushi County in Aksu, Xinjiang Province. The RSD of precision test of the five compounds were in the range of 0.60-2.22%, and the average recoveries ranged from 97.36% to 101.19%. Good linearity between specific chromatographic peak and component qualities were observed in the investigated ranges for all the analytes ( R 2 > 0.9997). The proposed method was successfully applied to determine the levels of five active components in sea buckthorn samples from Aksu in Xinjiang. The proposed method is simple, fast, sensitive, accurate, and suitable for quantitative assessment of the pulp and seed of sea buckthorn. Quantitative analysis method of protocatechuic acid, rutin, quercetin, kaempferol, and isorhamnetin in the extract of sea buckthorn pulp and seed is developed by high-performance liquid chromatography (HPLC) diode array detection.This method is simple and accurate; has strong specificity, good precision, and high recovery rate; and provides a reliable basis for further development of the substances in the pulp and seed of sea buckthorn.The method is widely used for content determination of active ingredients or physiologically active components in traditional Chinese medicine and its preparation Abbreviation used: PR: protocatechuic acid, RU

  15. New methods and materials for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, Philip John [Iowa State Univ., Ames, IA (United States)

    1996-04-23

    This paper describes methods for solid phase extraction and high performance liquid chromatography (HPLC). The following are described: Effects of Resin Sulfonation on the Retention of Polar Organic Compounds in Solid Phase Extraction; Ion-Chromatographic Separation of Alkali Metals In Non-Aqueous Solvents; Cation-Exchange Chromatography in Non-Aqueous Solvents; and Silicalite As a Stationary Phase For HPLC.

  16. New Highly-Sensitive Ultra-Performance Liquid Chromatography ...

    African Journals Online (AJOL)

    Purpose: To develop and validate a simple, rapid, sensitive and specific ultraperformance liquid chromatography mass spectrometry method for the quantification of the angiotensin II receptor antagonist, telmisartan (TEL), in human plasma. Methods: After simple protein precipitation using acetonitrile and methanol, TEL and ...

  17. Quantification of Quercetin and Rutin from Benincasa hispida Seeds and Carissa Congesta Roots by High-performance Thin Layer Chromatography and High-performance Liquid Chromatography.

    Science.gov (United States)

    Doshi, Gaurav Mahesh; Une, Hemant Devidas

    2016-01-01

    In Indian Ayurvedic system, Benincasa hispida (BH) and Carissa congesta (CC) are well-known plants used for major and minor ailments. BH has been regarded as Kushmanda, whereas CC has been used in immune-related disorders of the human system. Quercetin and rutin identified from the vast plethora of plant extracts have proved to possess ethnopharmacological relevance. In present studies, we have determined quercetin and rutin in terms of percentage in BH seeds and CC roots by high-performance thin layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC). After extraction and phytochemical screening, the extracts were subjected to quantification for the presence of quercetin and rutin by HPTLC and HPLC. HPTLC showed quercetin as 44.60, 27.13% and rutin as 32.00, 36.31% w/w, whereas HPLC revealed quercetin as 34.00, 35.00% and rutin as 21.99, 45.03% w/v in BH and CC extracts, respectively. The BH and CC extracts have elucidated peaks that were corresponding with standard peaks on undertaking chromatographic studies. Quercetin and rutin are isolated from BH seeds and CC roots by High Performance. Thin Layer Chromatography and High Performance Liquid Chromatography. HPTLC revealed presence of quercetin as 44.60, 27.13 % and rutin as 32.00, 36.31 % w/w. HPLC revealed presence of quercetin as 34.00, 35.00 % and rutin as 21.99, 45.03 % w/v. Abbreviation Used: HPTLC: High Performance Thin Layer Chromatography; HPLC: High Pressure Liquid Chromatography, UV: Ultraviolet, CC: Carissa congesta, BH: Benincasa hispida.

  18. High resolution gas chromatography analysis of rice bran oil

    Science.gov (United States)

    Yu, Fengxiang; Lin, Qinlu; Chen, Xu; Wei, Xiaojun

    To assess the nutritional value and safety quality of rice bran oil (RBO) ,fatty acids of RBO from 15 species rice come from Hunan Province were analyzed by high resolution gas chromatography (HRGC). Crude RBOs were extracted by hexane 3-times using a solvent-to-rice bran ratio of 3:1 (w/w) at 40°C and composition of RBOs was analyzed by HRGC. The result showed that main fatty acids of 15 kinds of RBO include myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), arachidic acid (C20:0), arachidonic acid (C20:1). It is strange that arachidonic acid (C20:1) is not listed in Chinese standard of RBO (GB11192-2003), and it exists in our samples of RBO. The average value of linolenic acid in RBOs is 1.6304% (range from 1.2425% to 2.131%), and it showed higher level comparing with Chinese standard that linolenic acid is less than 1.0%. The average value of USFA and SFA are 76.81% (range 75.96% to 82.06% ) and 20.15% (range 13.72% to 23.06%) respectively, and USFA content is close to olive oil (83.75%), peanut oil (81.75%) and soybean oil (85.86%). USFA in Jingyou 13 RBO is the highest content. The ratio of USFA to SFA content is 4:1 (range from 3.32 to 5.98:1). The ratio of SFA: MUFA: PUFA of 15 RBOs is 1: 2.2: 1.8, and ω6/ω3 ratio is 21.69 (range from16.54 to 27.28) and it is close to the 26:1 which is reported to be helpful to increase SOD activity. The oleic acid /linoleic acid ratio of 15 RBOs is 1.23:1 (rang from 1.04:1 to 1.42:1). Our data analyzed composition of RBOs from 15 species rice of China and will provide new evidence to revise RBO standard. It also helps us to assess nutritional value of RBOs and identify different RBOs from various species rice and places of origin.

  19. A high expression EGFR/cell membrane chromatography and online high performance liquid chromatography/mass spectrometry method for screening EGFR antagonists from Rhizoma Polygoni Cuspidati

    Directory of Open Access Journals (Sweden)

    Meng Sun

    2011-08-01

    Full Text Available The epidermal growth factor receptors (EGFRs in some tumor cells are significant targets for drug discovery. In this work, we have developed an EGFR cell membrane chromatography and online high performance liquid chromatography/mass spectrometry system for screening active component from Rhizoma Polygoni Cuspidati. As a result, resveratrol from Rhizoma Polygoni Cuspidati was found to be the active component acting on EGFR like gefitinib. There was a good relationship between their inhibiting effects on EGFR secretion and HEK293 EGFR cell growth in vitro. The EGFR/CMC-online-HPLC/MS system demonstrated fast and effective characteristics for screening leading compounds from traditional Chinese medicine.

  20. Detection of Geothermal Phosphite Using High Performance Liquid Chromatography

    Science.gov (United States)

    Pech, Herbe; Henry, Amanda; Khachikian, Crist S.; Salmassi, Tina M.; Hanrahan, Grady; Foster, Krishna L.

    2009-01-01

    Little is known about the pre-biotic mechanisms that initiated the bioavailability of phosphorus, an element essential to life. A better understanding of phosphorus speciation in modern earth environments representative of early earth, may help to elucidate the origins of bioavailable phosphorus. This paper presents the first quantitative measurements of phosphite in a pristine geothermal pool representative of early earth. Phosphite and phosphate were initially identified and quantified in geothermal pool and stream samples at Hot Creek Gorge near Mammoth Lakes, California using suppressed conductivity ion chromatography. Results confirmed the presence of 0.06 ± 0.02 μM of phosphite and 0.05 ± 0.01 μM of phosphate in a geothermal pool. In the stream, phosphite concentrations were below detection limit (0.04 μM) and phosphate was measured at 1.06 ± 0.36 μM. The presence of phosphite in the geothermal pool was confirmed using both chemical oxidation and ion chromatography/mass spectrometry. PMID:19921877

  1. Phytochemical Profile of Erythrina variegata by Using High-Performance Liquid Chromatography and Gas Chromatography-Mass Spectroscopy Analyses

    Directory of Open Access Journals (Sweden)

    Suriyavathana Muthukrishnan

    2016-08-01

    Full Text Available Natural products derived from plant sources have been utilized to treat patients with numerous diseases. The phytochemical constituents present in ethanolic leaf extract of Erythrina variegata (ELEV were identified by using high-performance liquid chromatography (HPLC and gas chromatography-mass spectroscopy (GC-MS analyses. Shade dried leaves were powdered and extracted with ethanol for analyses through HPLC to identify selected flavonoids and through GC-MS to identify other molecules. The HPLC analysis of ELEV showed the presence of gallic and caffeic acids as the major components at concentrations of 2.0 ppm and 0.1 ppm, respectively, as well as other components. GC-MS analysis revealed the presence of 3-eicosyne; 3,7,11,15-tetramethyl-2-hexadecen-1-ol; butanoic acid, 3-methyl-3,7-dimethyl-6-octenyl ester; phytol; 1,2-benzenedicarboxylic acid, diundecyl ester; 1-octanol, 2-butyl-; squalene; and 2H-pyran, 2-(7-heptadecynyloxy tetrahydro-derivative. Because pharmacopuncture is a new evolving natural mode that uses herbal extracts for treating patients with various ailments with minimum pain and maximum effect, the results of this study are particularly important and show that ELEV possesses a wide range of phytochemical constituents, as indicated above, as effective active principle molecules that can be used individually or in combination to treat patients with various diseases.

  2. Phytochemical Profile of Erythrina variegata by Using High-Performance Liquid Chromatography and Gas Chromatography-Mass Spectroscopy Analyses.

    Science.gov (United States)

    Muthukrishnan, Suriyavathana; Palanisamy, Subha; Subramanian, Senthilkumar; Selvaraj, Sumathi; Mari, Kavitha Rani; Kuppulingam, Ramalingam

    2016-08-01

    Natural products derived from plant sources have been utilized to treat patients with numerous diseases. The phytochemical constituents present in ethanolic leaf extract of Erythrina variegata (ELEV) were identified by using high-performance liquid chromatography (HPLC) and gas chromatography-mass spectroscopy (GC-MS) analyses. Shade dried leaves were powdered and extracted with ethanol for analyses through HPLC to identify selected flavonoids and through GC-MS to identify other molecules. The HPLC analysis of ELEV showed the presence of gallic and caffeic acids as the major components at concentrations of 2.0 ppm and 0.1 ppm, respectively, as well as other components. GC-MS analysis revealed the presence of 3-eicosyne; 3,7,11,15-tetramethyl-2-hexadecen-1-ol; butanoic acid, 3-methyl-3,7-dimethyl-6-octenyl ester; phytol; 1,2-benzenedicarboxylic acid, diundecyl ester; 1-octanol, 2-butyl-; squalene; and 2H-pyran, 2-(7-heptadecynyloxy) tetrahydro-derivative. Because pharmacopuncture is a new evolving natural mode that uses herbal extracts for treating patients with various ailments with minimum pain and maximum effect, the results of this study are particularly important and show that ELEV possesses a wide range of phytochemical constituents, as indicated above, as effective active principle molecules that can be used individually or in combination to treat patients with various diseases. Copyright © 2016. Published by Elsevier B.V.

  3. Gas chromatography-mass spectrometry and high-performance liquid chromatography-diode array detection for dating of paper ink.

    Science.gov (United States)

    Díaz-Santana, Oscar; Vega-Moreno, Daura; Conde-Hardisson, Francisco

    2017-09-15

    An extraction and determination method is shown for the analysis of dyes and solvents present in two types of ballpoint pen inks that are deposited onto paper. Ink extracts are analysed using a combination of gas chromatography with mass spectrometry (GC-MS), and high-pressure liquid chromatography with photodiode array detection (HPLC-DAD), within a single sample extraction procedure. Seventeen solvents and thirteen dyes contained in two Montblanc® inks (black and blue) were monitored for 45 months at monthly intervals, in order to determine variations in the concentrations of the compounds over time. We also studied the relative variations between different compounds and the generation of degradation products such as phenol. The concentration data obtained from these compounds during their exposure have been analysed and a multiple regression model is developed for each ink type that allows an estimate of the exposure time of the ink on paper with a maximum error of between 4 and 7 months. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. High-resolution fractionation after gas chromatography for Effect Directed Analysis.

    NARCIS (Netherlands)

    Pieke, E.; Heus, F.A.H.; Kamstra, J.; Mladic, M.; van Velzen, M.; Kamminga, D.; Lamoree, M.H.; Hamers, T.; Leonards, P.E.G.; Niessen, W.M.A.; Kool, J.

    2013-01-01

    This research presents an analytical technology for highly efficient, high-resolution, and high-yield fractionation of compounds after gas chromatography (GC) separations. The technology is straightforward, does not require sophisticated cold traps or adsorbent traps, and allows collecting large

  5. Simultaneous quantification of polyherbal formulations containing Rhodiola rosea L. and Eleutherococcus senticosus Maxim. using rapid resolution liquid chromatography (RRLC).

    Science.gov (United States)

    Ma, Yuan-Chun; Wang, Xiao-Qiang; Hou, Feifei; Ma, Jie; Luo, Mai; Lu, Shane; Jin, Peter; Chen, Alice; Xu, Iris; Patel, Asmita V; Gorecki, Derek

    2011-07-15

    An RRLC method capable of simultaneous identification and rapid quantification of six biologically active compounds (salidroside, tyrosol, rosarin, rosavin, rosin, rosiridin) in Rhodiola rosea L. and two active compounds (eleutheroside B and eleutheroside E) in Eleutherococcus senticosus Maxim. was developed. The chromatographic analyses were performed on a reversed phase Phenomenex C18 (2)-HST column at 40°C with a neutral mobile phase (purified water and acetonitrile) gradient system at a flow rate of 1.0ml/min and UV detection at 205 and 220nm simultaneously. Baseline separation of eight active compounds was achieved within 8min. This developed method provides good linearity (R>0.9997), precision (RSDrosea and E. senticosus raw herbs, commercial extracts, as well as polyherbal formulations containing R. rosea and E. senticosus as ingredients. This RRLC method is accurate and sensitive; in addition, it greatly increases sample analysis throughput with reduced analysis time, which is suitable for routine quality control analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Identification of the Related Substances in Ampicillin Capsule by Rapid Resolution Liquid Chromatography Coupled with Electrospray Ionization Tandem Mass Spectrometry

    National Research Council Canada - National Science Library

    Zhang, Lei; Cheng, Xian Long; Liu, Yang; Liang, Miao; Dong, Honghuan; Lv, Beiran; Yang, Wenning; Luo, Zhiqiang; Tang, Mingmin

    2014-01-01

    ... the original work is properly cited. 1. Introduction Ampicillin is an important semisynthetic β -lactam antibiotic and it is still widely used nowadays because of its good efficacy in urinary tract ...

  7. Extraction and Purification of Glucoraphanin by Preparative High-Performance Liquid Chromatography (HPLC)

    Science.gov (United States)

    Lee, Iris; Boyce, Mary C.

    2011-01-01

    A student activity that focuses on the isolation of glucoraphanin from broccoli using preparative high-performance liquid chromatography (HPLC) is presented here. Glucoraphanin is a glucosinolate, whose byproducts are known to possess anticancer properties. It is present naturally at high levels in broccoli and other "Brassica" vegetables. This…

  8. Protein mapping by two-dimensional high performance liquid chromatography

    NARCIS (Netherlands)

    Wagner, K.; Racaityte, K.; Unger, K.K.; Miliotis, T.; Edholm, L.E.; Bischoff, Rainer; Marko-Varga, G

    2000-01-01

    Current developments in drug discovery in the pharmaceutical industry require highly efficient analytical systems for protein mapping providing high resolution, robustness, sensitivity, reproducibility and a high throughput of samples. The potential of two-dimensional (2D) HPLC as a complementary

  9. Developments in high-speed countercurrent chromatography and its applications in the separation of terpenoids and saponins.

    Science.gov (United States)

    Song, Hua; Lin, Jianhong; Zhu, Xuan; Chen, Qing

    2016-04-01

    High-speed countercurrent chromatography is a liquid-liquid separation chromatographic technique, which has the unique feature of eliminating irreversible adsorption using liquid support medium, and is widely used in research and development of traditional Chinese medicine, biochemistry, food, environment analysis, and so on. In this review, some new developments of countercurrent chromatography, for instance cross-axis countercurrent chromatography, dual countercurrent chromatography, foam countercurrent chromatography, and pH-zone-refining countercurrent chromatography are presented. Furthermore, the research and progress in high-speed countercurrent chromatography techniques and its application in the separation and purification of terpenoids and saponins are reviewed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. High Speed Counter Current Chromatography-A Support free LC Technique

    OpenAIRE

    Garima Jain; Kona S Srinivasa; Aarti Sharma; Kaushal k Chandrul; Neha sethi; Ankit anand

    2009-01-01

    As separation of components is the major requirement of an analytical chemist, there is always a need of a convenient
    high throughput technique with minimum sample loss, high efficiency, high resolution, ease of sample
    recovery without contamination. This leads to the development of High Speed Counter Current Chromatography
    (HSCCC) in which stationary phase is liquid instead of solid that provides a lot of advantages...

  11. Coupling nanoliter high-performance liquid chromatography to inductively coupled plasma mass spectrometry for arsenic speciation.

    Science.gov (United States)

    Cheng, Heyong; Shen, Lihuan; Liu, Jinhua; Xu, Zigang; Wang, Yuanchao

    2017-12-23

    Nanoliter high-performance liquid chromatography shows low consumption of solvents and samples, offering one of the best choices for arsenic speciation in precious samples in combination with inuctively coupled plasma mass spectrometry. A systematic investigation on coupling nanoliter high-performance liquid chromatography to inductively coupled plasma mass spectrometry from instrument design to injected sample volume and mobile phase was performed in this study. Nanoflow mobile phase was delivered by flow splitting using a conventional high-pressure pump with reuse of mobile phase waste. Dead volume was minimized to 60 nL for the sheathless interface based on the previously developed nanonebulizer. Capillary columns for nanoliter high-performance liquid chromatography were found to be sensitive to sample loading volume. An apparent difference was also found between the mobile phases for nanoliter and conventional high-performance liquid chromatography. Baseline separation of arsenite, arsenate, monomethylarsenic, and dimethylarsenic was achieved within 11 min on a 15 cm C18 capillary column and within 12 min on a 25 cm strong anion exchange column. Detection limits of 0.9-1.8 μg/L were obtained with precisions variable in the range of 1.6-4.2%. A good agreement between determined and certified values of a certified reference material of human urine (GBW 09115) validated its accuracy along with good recoveries (87-102%). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. [Isolation of toxic peptides from Amanita phalloides and their analysis using high-performance liquid chromatography].

    Science.gov (United States)

    Hampl, J

    1993-08-05

    The objective of the work is isolation of toxic peptides from Amanita phalloides--amatoxins (alfa-, beta-, gamma-amanitin) and phallotoxins (phalloidin, phallacidin, phallisin, phallisacin) by liquid chromatography on Sephadex LH-20 according to Yocum modification. Seven main toxins were isolated in centigram amounts. The purity of the toxins isolated was verified by the characteristics of their absorbance spectra, by thin layer chromatography (TLC) and high-performance liquid chromatography on reversed phase (RP-HPLC). The fraction of acid phallotoxins which appears homogenous in TLC and Sephadex LH-20 was separated into 5 substances (four of which are phallotoxins) by preparative RP-HPLC technique. The toxins isolated are sufficiently pure to be used as standards in HPLC.

  13. Development of a high performance liquid chromatography method ...

    African Journals Online (AJOL)

    Recovery accuracy was 99.77 - 101.10, 100.50 - 101.95 and 99.20 - 100.13 % for TH, GF and DH, respectively; precision (RSD) was < 2.0. Conclusion: The proposed method is highly selective, sensitive, precise, and accurate, and would suitable for the simultaneous analysis of TH, GF, and DH in elixir dosage form.

  14. Buffer-Free High Performance Liquid Chromatography Method for ...

    African Journals Online (AJOL)

    Purpose: To develop and validate a simple, economical and reproducible high performance liquid chromatographic (HPLC) method for the determination of theophylline in pharmaceutical dosage forms. Method: Caffeine was used as the internal standard and reversed phase C-18 column was used to elute the drug and ...

  15. Sorption of catechins under conditions of reverse-phase high-efficiency liquid chromatography

    Science.gov (United States)

    Shafigulin, R. V.; Egorova, K. V.; Bulanova, A. V.

    2010-08-01

    The physico-chemical principles of catechin sorption from various polar solvents onto silica gel modified with octadecyl groups were studied. Thermodynamic characteristics of the sorption were calculated, and the applicability of different models of retention was demonstrated for catechins under the conditions of reverse-phase high-efficiency liquid chromatography.

  16. Simultaneous analysis of small organic acids and humic acids using high performance size exclusion chromatography

    NARCIS (Netherlands)

    Qin, X.P.; Liu, F.; Wang, G.C.; Weng, L.P.

    2012-01-01

    An accurate and fast method for simultaneous determination of small organic acids and much larger humic acids was developed using high performance size exclusion chromatography. Two small organic acids, i.e. salicylic acid and 2,3-dihydroxybenzoic acid, and one purified humic acid material were used

  17. An Advanced, Interactive, High-Performance Liquid Chromatography Simulator and Instructor Resources

    Science.gov (United States)

    Boswell, Paul G.; Stoll, Dwight R.; Carr, Peter W.; Nagel, Megan L.; Vitha, Mark F.; Mabbott, Gary A.

    2013-01-01

    High-performance liquid chromatography (HPLC) simulation software has long been recognized as an effective educational tool, yet many of the existing HPLC simulators are either too expensive, outdated, or lack many important features necessary to make them widely useful for educational purposes. Here, a free, open-source HPLC simulator is…

  18. High-Performance Liquid Chromatography in the Undergraduate Chemical Engineering Laboratory

    Science.gov (United States)

    Frey, Douglas D.; Guo, Hui; Karnik, Nikhila

    2013-01-01

    This article describes the assembly of a simple, low-cost, high-performance liquid chromatography (HPLC) system and its use in the undergraduate chemical engineering laboratory course to perform simple experiments. By interpreting the results from these experiments students are able to gain significant experience in the general method of…

  19. Determination for Synthesis and Content of Tetrahydropalmatine Based on High Performance Liquid Chromatography

    OpenAIRE

    Yuanming Zhang

    2014-01-01

    Tetrahydropalmatine is a kind of food additive with useful medicine value (dietary supplement), the tetrahydropalmatine synthetic process by using high performance liquid chromatography method was researched in the study, the experiments show that the dissolution rate of active ingredients in the tetrahydropalmatine water extract synthesized by this method has increased and the amount of active ingredient has greatly improved.

  20. Comparison of high performance liquid chromatography and enzymatic analysis of soluble carbohydrates in loblolly pine

    Science.gov (United States)

    Patricia L. Faulkner; Michele M. Schoeneberger; Kim H. Ludovici

    1993-01-01

    Foliar tissue was collected from a field study designed to test impacts of atmospheric pollutants on loblolIy pine (Pinus taeda L.) seedlings. Standard enzymatic (ENZ) and high performance liquid chromatography (HPLC) methods were used to analyze the tissue for soluble sugars. A comparison of the methods revealed no significant diffennces in accuracy...

  1. DETERMINATION OF CHLOROPHENOLS, NITROPHENOLS, AND METHYLPHENOLS IN GROUND-WATER SAMPLES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Science.gov (United States)

    A high performance liquid chromatography (HPLC) method was developed to quantitatively determine phenolic compounds and their isomers in aqueous samples. The HPLC method can analyze a mixture of 15 contaminants in the same analytical run with an analysis time of 25 minutes. The...

  2. DETERMINATION OF CHLOROPHEONIS, NITROPHENOIS AND METHYLPHENOIS IN GROUND-WATER SAMPLES USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Science.gov (United States)

    A high performance liquid chromatography (HPLC) method was developed to quantitatively determine phenolic compounds and their isomers in aqueous samples. The HPLC method can analyze a mixture of 15 contaminants in the same analytical run with an analysis time of 25 minutes. The...

  3. High-performance liquid chromatography determination of dapsone, monoacetyldapsone, and pyrimethamine in filter paper blood spots

    DEFF Research Database (Denmark)

    Rønn, A M; Lemnge, M M; Angelo, H R

    1995-01-01

    A high-performance liquid chromatography method for the simultaneous analysis of dapsone (DDS), the major metabolite of DDS, monoacetyldapsone (MADDS), and pyrimethamine (PYR) was modified for capillary blood samples obtained by finger prick and dried on filter paper. Limit of quantitation using...

  4. Deformation and degradation of polymers in ultra-high-pressure liquid chromatography

    NARCIS (Netherlands)

    Uliyanchenko, E.; van der Wal, S.; Schoenmakers, P.J.

    2011-01-01

    Ultra-high-pressure liquid chromatography (UHPLC) using columns packed with sub-2 μm particles has great potential for separations of many types of complex samples, including polymers. However, the application of UHPLC for the analysis of polymers meets some fundamental obstacles. Small particles

  5. Benzoin Condensation: Monitoring a Chemical Reaction by High-Pressure Liquid Chromatography

    Science.gov (United States)

    Bhattacharya, Apurba; Purohit, Vikram C.; Bellar, Nicholas R.

    2004-01-01

    High-pressure liquid chromatography (HPLC) is the preferred method of separating a variety of materials in complex mixtures such as pharmaceuticals, polymers, soils, food products and biological fluids and is also considered to be a powerful analytical tool in both academia and industry. The use of HPLC analysis as a means of monitoring and…

  6. Nitrate and nitrite content in bottled beverages by ion-pair high-performance liquid chromatography.

    Science.gov (United States)

    Song, Yang; Deng, Gui-Fang; Xu, Xiang-Rong; Chen, Yong-Hong; Chen, Feng; Li, Hua-Bin

    2013-01-01

    Nitrate and nitrite levels in six types of beverages--total of 292 individual samples from 73 brands (four bottles each)--from Guangzhou city in China were evaluated by ion-pair high-performance liquid chromatography. All samples contained nitrate. Nitrate and nitrite ranges were 0.43-46.08 and beverages.

  7. Comparison of microemulsion electrokinetic chromatography with high-performance liquid chromatography for fingerprint analysis of resina draconis.

    Science.gov (United States)

    Cao, Yuhua; Gong, Wenjun; Li, Nan; Yin, Changna; Wang, Yun

    2008-11-01

    Microemulsion electrokinetic chromatography (MEEKC) has been developed for fingerprint analysis of resina draconis, a substitute for sanguis draconis in the Chinese market. The microemulsion as the running buffer was made up of 3.3% (w/v) sodium dodecyl sulfate (SDS), 6.6% (w/v) n-butanol, 0.8% (w/v) n-octane, and 10 mmol/L sodium tetraborate buffer (pH 9.2), which was also used as the solvent for ultrasonic extraction of both water- and fat-soluble compounds in the traditional Chinese medicine samples. Four batches of resina draconis obtained from different pharmaceutical factories located in different geographic regions were used to establish the electrophoretic fingerprint. MEEKC was performed using a Beckman PACE/MDQ system equipped with a diode-array detector and with monitoring at 280 nm. The fingerprint of resina draconis comprised 27 common peaks within 100 min. The relative standard deviations of the relative migration time of these common peaks were less than 2.1%. Through repetitive injection of the sample solution six times in 24 h, all relative standard deviations of the migration time and peak area of loureirin A and loureirin B were less than 2.5 and 3.8%, which demonstrated that the method had good stability and reproducibility. The relative peak areas of these common peaks in the electropherograms of four batches of resina draconis were processed with two mathematical methods, the correlation coefficient and the interangle cosine, to valuate the similarity. The values of the similarity degree of all samples were more than 0.91, which showed resina draconis samples from different origins were consistent. On the other hand, high-performance liquid chromatography (HPLC) coupled with photodiode-array detection was also applied to establish the fingerprint of resina draconis. The samples were separated with a LiChrospher C(18) column using acetonitrile (solvent A) and water containing 0.1% H(3)PO(4) (solvent B) as the mobile phase in linear gradient

  8. High-throughput screening for enzyme inhibitors using frontal affinity chromatography with liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Ng, Ella S M; Yang, Feng; Kameyama, Akihiko; Palcic, Monica M; Hindsgaul, Ole; Schriemer, David C

    2005-10-01

    This work presents new frontal affinity chromatography (FAC) methodologies for high-throughput screening of compound libraries, designed to increase screening rates and improve sensitivity and ruggedness in performance. A FAC column constructed around the enzyme N-acetylglucosaminyltransferase V (GnT-V) was implemented in the identification of potential enzyme inhibitors from two libraries of trisaccharides. Effluent from the FAC column was fractionated, sequentially processed via LC/MS, and referenced to a similar analysis through a control FAC column lacking the enzyme. The resulting multidimensional data sets were compared across corresponding sample and control fractions to identify binders, in a semiautomated approach. A strong binder in the protonated form at m/z 795 was identified from the first library of 81 compounds, exhibiting an estimated Kd value of 0.3 microM. Other binders yielded Kd values ranging from 0.35 to 3.35 microM. To demonstrate the improvement in performance of this FAC-LC/MS approach over the conventional online FAC/MS approach, 15 compounds from this library were blended with a second library of 1000 synthetic trisaccharides and screened against GnT-V. All ligands in the 15-compound set were identified in this larger screen, and no ligands of greater affinity than compound 1 were found. Our results show that FAC-LC/MS is a reliable method for screening large compound libraries directly and useful for large-scale ligand discovery initiatives.

  9. ANALYSIS OF DRUG INTERACTIONS WITH HIGH DENSITY LIPOPROTEIN BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    Science.gov (United States)

    Chen, Sike; Sobansky, Matthew R.; Hage, David S.

    2009-01-01

    Columns containing immobilized lipoproteins were prepared for the analysis of drug interactions with these particles by high-performance affinity chromatography. This approach was evaluated by using it to examine the binding of high density lipoprotein (HDL) to the drugs propranolol or verapamil. HDL was immobilized by the Schiff base method onto silica and gave HPLC columns with reproducible binding to propranolol over four to five days of continuous operation at pH 7.4. Frontal analysis experiments indicated that two types of interactions were occurring between R/S-propranolol and HDL at 37°C: saturable binding with an association equilibrium constant (Ka) of 1.1–1.9 × 105 M−1, and non-saturable binding with an overall affinity constant (n Ka) of 3.7–4.1 × 104 M−1. Similar results were found at 4 and 27°C. Verapamil also gave similar behavior, with a Ka of 6.0 × 104 M−1 at 37°C for the saturable sites and a n Ka value for the non-saturable sites of 2.5 × 104 M−1. These measured affinities gave good agreement with solution-phase values. The results indicated HPAC can be used to study drug interactions with HDL, providing information that should be valuable in obtaining a better description of how drugs are transported within the body. PMID:19833090

  10. Determination of Finasteride in Tablets by High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    K. Basavaiah

    2007-01-01

    Full Text Available A rapid, highly sensitive high performance liquid chromatographic method has been developed for the determination of finasteride(FNS in bulk drug and in tablets. FNS was eluted from a ODS C18 reversed phase column at laboratory temperature (30 ± 2°C with a mobile phase consisting of methanol and water (80+20 at a flow rate of 1 mL min-1 with UV detection at 225 nm. The retention time was ∼ 6.1 min and each analysis took not more than 10 min. Quantitation was achieved by measurement of peak area without using any internal standard. Calibration graph was linear from 2.0 to 30 μg mL-1 with limits of detection (LOD and quantification (LOQ being 0.2 and 0.6 μg mL-1, respectively. The method was validated according to the current ICH guidelines. Within-day co efficients of variation (CV ranged from 0.31 to 0.69% and between-day CV were in the range 1.2-3.2%. Recovery of FNS from the pharmaceutical dosage forms ranged from 97.89 – 102.9 with CV of 1.41-4.13%. The developed method was compared with the official method for FNS determination in its tablet forms.

  11. [Determination of amygdalin in hawthorn by high performance liquid chromatography].

    Science.gov (United States)

    Lü, Weifeng; Ding, Mingyu

    2005-09-01

    A suitable method for extraction of amygdalin from hawthorn has been established. At first, the lipophilic components were removed with petroleum ether by ultrasonic extraction. The amygdalin was then extracted by methanol in a Soxhlet's apparatus. For quantitation, a high performance liquid chromatographic method was developed by using a reversed-phase C18 column, mobile phase of methanol-water (15:85, v/v) and a detection wavelengh of 215 nm. It can be concluded that the content of amygdalin is higher in the seeds than that in the hawthorn powder without the seeds and the yield of amygdalin is higher in the hawthorn pieces than that in the hawthorn powder.

  12. Rapid analysis of the interactions between drugs and human serum albumin (HSA) using high-performance affinity chromatography (HPAC)

    OpenAIRE

    Kim, Hee Seung; Wainer, Irving W.

    2008-01-01

    This study used a combination of zonal elution and frontal affinity chromatography on immobilized human serum albumin (HSA) high-performance affinity chromatography (HPAC) column to examine the association constants of various compounds that have been studied by equilibrium dialysis or ultra filtration. A standard plot was generated from retention factors of reference compounds using zonal elution chromatography against association constants of reference compounds using frontal affinity chrom...

  13. Separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Xiaofeng Chi

    2014-01-01

    Full Text Available An effective method for the rapid separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC was successfully established. In the present study, a two-phase solvent system composed of chloroform-n-butanol-methanol-water (4:1:4:2, v/v/v/v was used for HSCCC separation. A one-step separation in 4 h from 150 mg of crude extract produced 26.3 mg of trans-resveratrol-3-O-glucoside, 42.0 mg of pieceid-2"-O-gallate, and 17.9 mg of trans-resveratrol with purities of 99.1%, 97.8%, and 99.4%, respectively, as determined by high-performance liquid chromatography (HPLC. The chemical structures of these compounds were identified by nuclear magnetic resonance (NMR spectroscopy.

  14. DEVELOPMENT OF SULFHYDRYL-REACTIVE SILICA FOR PROTEIN IMMOBILIZATION IN HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    OpenAIRE

    Mallik, Rangan; Wa, Chunling; Hage, David S.

    2007-01-01

    Two techniques were developed for the immobilization of proteins and other ligands to silica through sulfhydryl groups. These methods made use of maleimide-activated silica (the SMCC method) or iodoacetyl-activated silica (the SIA method). The resulting supports were tested for use in high-performance affinity chromatography by employing human serum albumin (HSA) as a model protein. Studies with normal and iodoacetamide-modified HSA indicated that these methods had a high selectivity for sulf...

  15. Separation and identification of polyphenols in apple pomace by high-speed counter-current chromatography and high-performance liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Cao, Xueli; Wang, Cong; Pei, Hairun; Sun, Baoguo

    2009-05-08

    Apple pomace, a by-product in the processing of apple juice, was investigated as a potential source of polyphenols. Two methods of separation and purification of polyphenols from apple pomace extract were established by combination of gel chromatography with high-speed counter-current chromatography (HSCCC) and solvent extraction with HSCCC, respectively. The optimal separation was performed on a Sephadex LH-20 column using gradient aqueous ethanol as eluting solvent from 0% to 100% in increments of 10%. HPLC analysis indicated that main polyphenols existed in fractions eluted between 40% and 50% aqueous ethanol. The fractions of interest from column were separated by HSCCC with the solvent system hexane-ethyl acetate-1% aqueous acetic acid (0.5:9.5:10, v/v/v). Ethyl acetate fractionation of the apple pomace extract followed by direct HSCCC separation by the same solvent system in the volume ratio of 1:9:10 also produced a good separation of the main polyphenols of interest. Six high-purity polyphenols were achieved tentatively and identified by HPLC/MS: chlorogenic acid (1, m/z 354), quercetin-3-glucoside/quercetin-3-glacaside (2, m/z 464), quercetin-3-xyloside (3, m/z 434), phloridzin (4, m/z 436), quercetin-3-arabinoside (5, m/z 434), and quercetin-3-rhamnoside (6, m/z 448). These results provided a preliminary foundation for further development and exploration of apple pomace.

  16. Preparative separation of punicalagin from pomegranate husk by high-speed countercurrent chromatography.

    Science.gov (United States)

    Lu, Jingjing; Wei, Yun; Yuan, Qipeng

    2007-09-15

    Punicalagin, the main ingredient of pomegranate (Punica granatum L.) husk, is a high molecular weight polyphenolic compound. It has shown remarkable pharmacological activities attributed in the presence of dissociable OH groups. To isolate punicalagin, previous methods included labor intensive and expensive solid phase extractions by column chromatography (C-18, polyamides, dellulose, Sephadex Lipophilic LH-20, Diaion HP20). High-speed countercurrent chromatography (HSCCC) was used for isolation and purification of punicalagin from pomegranate husk. Using preparative HSCCC about a 350 mg amount of the crude extract was separated, yielding 105 mg of punicalagin at a high-purity of over 92%. Eighty milligrams of gallic acid was simultaneously separated as another product, at a purity of 75%.

  17. Separation of catechin constituents from five tea cultivars using high-speed counter-current chromatography.

    Science.gov (United States)

    Kumar, N Savitri; Rajapaksha, Maheshinie

    2005-08-12

    Catechins were extracted from five different tea (Camellia sinensis L.) cultivars. High-speed counter-current chromatography was found to be an efficient method for the separation of seven catechins from the catechin extracts. High-performance liquid chromatography was used to assess the purity of the catechins isolated. Epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and epigallocatechin (EGC) of high purity (91-99%) were isolated in high yield after a single high-speed counter-current chromatography run. The two-phase solvent mixtures used for the separation of the catechin extracts were hexane:ethyl acetate:methanol:water (1:6:1:6 for TRI 2023); (1:7:1:7 for TRI 2025 and TRI 2043); (1:5:1:5 for TRI 3079) and (1:6.5:1:6.5 for TRI 4006). Fresh tea shoots from the tea cultivar TRI 2023 (150 g) gave 440 mg of 96% pure EGCG while TRI 2025 (235 g) gave 347 mg of 99% pure EGCG and 40 mg of 97% ECG, and TRI 3079 (225 g) gave 432 mg of 97% pure EGCG and 32 mg of 96% pure ECG. Tea cultivar TRI 4006 (160 g) gave EGCG (272 mg, 96% pure) and EGC (104 mg, 90% pure). 1H and 13C NMR chemical shifts for catechin gallate (CG), EGC, ECG, EGCG and epigallocatechin 3,5-di-O-gallate (EGCDG) in CD3OD were also recorded.

  18. Preparation and Characterization of a Polymeric Monolithic Column for Use in High-Performance Liquid Chromatography (HPLC)

    Science.gov (United States)

    Bindis, Michael P.; Bretz, Stacey Lowery; Danielson, Neil D.

    2011-01-01

    The high-performance liquid chromatography (HPLC) experiment, most often done in the undergraduate analytical instrumentation laboratory course, generally illustrates reversed-phase chromatography using a commercial C[subscript]18 silica column. To avoid the expense of periodic column replacement and introduce a choice of columns with different…

  19. Rapid detection of malto-oligosaccharide-forming bacterial amylases by high performance anion-exchange chromatography

    DEFF Research Database (Denmark)

    Duedahl-Olesen, Lene; Larsen, K. L.; Zimmermann, W.

    2000-01-01

    High performance anion-exchange chromatography with pulsed amperometric detection was applied for the rapid analysis of malto-oligosaccharides formed by extracellular enzyme preparations from 49 starch-degrading bacterial strains isolated from soil and compost samples. Malto-oligosaccharide-formi......High performance anion-exchange chromatography with pulsed amperometric detection was applied for the rapid analysis of malto-oligosaccharides formed by extracellular enzyme preparations from 49 starch-degrading bacterial strains isolated from soil and compost samples. Malto......-oligosaccharide-forming amylases, indicated by a predominant formation of maltohexaose from starch, were produced by enzyme preparations from four of the isolates growing at pH 7.0 and 10....

  20. High-pressure liquid chromatography with direct injection of gas sample.

    Science.gov (United States)

    Astanin, Anton I; Baram, Grigory I

    2017-06-09

    The conventional method of using liquid chromatography to determine the composition of a gaseous mixture entails dissolving vapors in a suitable solvent, then obtaining a chromatograph of the resulting solution. We studied the direct introduction of a gaseous sample into a C18 reversed-phase column, followed by separation of the components by HPLC with UV detection. Since the chromatography was performed at high pressure, vapors readily dissolved in the eluent and the substances separated in the column as effectively as in liquid samples. Samples were injected into the column in two ways: a) through the valve without a flow stop; b) after stopping the flow and relieving all pressure. We showed that an injectable gas volume could reach 70% of column dead volume. When an injected gaseous sample volume was less than 10% of the column dead volume, the resulting peaks were symmetrical and the column efficiency was high. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Isolation of deoxypodophyllotoxin and podophyllotoxin from Juniperus sabina by high speed counter current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.; Yang, Y.; Chen, Q.; Kasimu, R.; Aisa, H.A.

    2016-11-01

    Deoxypodophyllotoxin and podophyllotoxin are known for their excellent anti-proliferative and anti-tumor activities, therefore large amount of pure compounds is urgently needed as authentic standards for various in vivo and in vitro studies. In this paper, an effective, rapid separation and purification method of deoxypodophyllotoxin and podophyllotoxin from the crude extract of Juniperus sabina was established using high speed counter current chromatography (HSCCC). HSCCC was performed with atwo phase solvent system comprising of n-hexane-ethylacetate-methanol-water (3:5:3:5, v/v) at the flow rate of 2mL/min at the speed of 850 rpm. 34.8 mg of deoxypodophyllotoxin and 7.9 mg of podophyllotoxin were obtained from 200 mg crude sample with a purity of 96.5% and 94.4%, respectively, as determined by high performance liquid chromatography (HPLC). (Author)

  2. Preparative Isolation of Three Anthraquinones from Rumex japonicus by High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Shuying Guo

    2011-01-01

    Full Text Available Three anthraquinones—emodin, chrysophanol, and physcion—were successfully purified from the dichloromethane extract of the Chinese medicinal herb Rumex japonicus by high-speed counter-current chromatography (HSCCC. The extract was separated with n-hexane–ethanol–water (18:22:3, v/v/v as the two-phase solvent system and yielded 3.4 mg of emodin, 24.1 mg of chrysophanol, and 2.0 mg of physcion from 500 mg of sample with purities of 99.2 %, 98.8% and 98.2%, respectively. The HSCCC fractions were analyzed by high-performance liquid chromatography (HPLC and the chemical structures of the three anthraquinones were confirmed by 1H-NMR and 13C-NMR analysis. This is the first time these anthraquinones have been obtained from R. japonicus by HSCCC.

  3. Determination of food preservatives and saccharin by high-performance liquid chromatography.

    Science.gov (United States)

    Leuenberger, U; Gauch, R; Baumgartner, E

    1979-05-21

    The quantitative analysis of benzoic and sorbic acid, methyl, ethyl and propyl esters of p-hydroxybenzoic acid and saccharin in foodstuffs is described. These compounds are quantitatively extracted with disposable clean-up columns packed with Extrelut and simultaneously determined by high-performance liquid chromatography on reversed-phase columns. Complicated matrices such as cheese, cake, ketchup and chocolate were tested and recoveries were generally better than 95% in the concentration ranges normally used in the food industry.

  4. DETECTION OF HETEROGENEOUS DRUG-PROTEIN BINDING BY FRONTAL ANALYSIS AND HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    OpenAIRE

    Tong, Zenghan; Joseph, K.S.; Hage, David S.

    2011-01-01

    This study examined the use of frontal analysis and high-performance affinity chromatography for detecting heterogeneous binding in biomolecular interactions, using the binding of acetohexamide with human serum albumin (HSA) as a model. It was found through the use of this model system and chromatographic theory that double-reciprocal plots could be used more easily than traditional isotherms for the initial detection of binding site heterogeneity. The deviations from linearity that were seen...

  5. BIOINTERACTION ANALYSIS BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY: KINETIC STUDIES OF IMMOBILIZED ANTIBODIES

    OpenAIRE

    Nelson, Mary Anne; Moser, Annette; Hage, David S.

    2009-01-01

    A system based on high-performance affinity chromatography was developed for characterizing the binding, elution and regeneration kinetics of immobilized antibodies and immunoaffinity supports. This information was provided by using a combination of frontal analysis, split-peak analysis and peak decay analysis to determine the rate constants for antibody-antigen interactions under typical sample application and elution conditions. This technique was tested using immunoaffinity supports that c...

  6. Preparation of sesquiterpenoids from Tussilago farfara L. by high-speed counter-current chromatography

    OpenAIRE

    Kun Cao; Yi Xu; Tian-Ming Zhao; Qing Zhang

    2016-01-01

    Background: Sesquiterpenoids, such as tussilagone, has effects of raising blood pressure, antiplatelet aggregation, and anti-inflammation activities, which is regarded as index compound for quality control of Tussilago farfara L. Objective: This study was aimed to obtain an effective method for fast isolation of sesquiterpenoids from T. farfara L. by high-speed counter-current chromatography (HSCCC). Materials and Methods: A solvent optimization method for HSCCC was presented, i.e., the separ...

  7. High-performance liquid chromatography for assaying NAD glycohydrolase from Neurospora crassa conidia.

    Science.gov (United States)

    Pietta, P; Pace, M; Menegus, F

    1983-06-01

    A rapid and sensitive high-performance liquid chromatographic technique was developed to determinate NAD glycohydrolase (EC 3.2.2.5.) activity from Neurospora crassa conidia. The separation of the assay substrate and products was achieved by isocratic reverse-phase chromatography and the peaks were detected by the absorbance at 259 nm. Quantities of NAD+ and nicotinamide as small as 10 pmol could be measured.

  8. Serum Protein Profile Study of Clinical Samples Using High Performance Liquid Chromatography-Laser Induced Fluorescence

    DEFF Research Database (Denmark)

    Karemore, Gopal Raghunath; Ukendt, Sujatha; Rai, Lavanya

    2009-01-01

    The serum protein profiles of normal subjects, patients diagnosed with cervical cancer, and oral cancer were recorded using High Performance Liquid Chromatography combined with Laser Induced Fluorescence detection (HPLC-LIF). Serum protein profiles of the above three classes were tested...... for establishing the ability of HPLC-LIF protein profiling technique for discrimination, using hard clustering and Fuzzy clustering methods. The clustering algorithms have quite successfully classified the profiles as belonging to normal, cancer of cervix, and oral cancer conditions....

  9. High-throughput protein purification under denaturating conditions by the use of cation exchange chromatography.

    Science.gov (United States)

    Alm, Tove; Steen, Johanna; Ottosson, Jenny; Hober, Sophia

    2007-06-01

    A high-throughput protein purification strategy using the polycationic Z(basic) tag has been developed. In order for the strategy to be useful both for soluble and less soluble proteins, a denaturating agent, urea, was used in all purification steps. First, four target proteins were genetically fused to the purification tag, Z(basic). These protein constructs were purified by cation exchange chromatography and eluted using a salt gradient. From the data achieved, a purification strategy was planned including stepwise elution to enable parallel protein purification using a laboratory robot. A protocol that includes all steps, equilibration of the chromatography resin, load of sample, wash, and elution, all without any manual handling steps, was handled by the laboratory robot. The program allows automated purification giving milligram amounts of pure recombinant protein of up to 60 cell lysates. In this study 22 different protein constructs, with different characteristics regarding pI and solubility, were successfully purified by the laboratory robot. The data show that Z(basic) can be used as a general purification tag also under denaturating conditions. Moreover, the strategy enables purification of proteins with different pI and solubility using ion exchange chromatography (IEXC). The procedure is highly reproducible and allows for high protein yield and purity and is therefore a good complement to the commonly used His(6)-tag.

  10. Development and validation of high-performance liquid chromatography and high-performance thin-layer chromatography methods for the quantification of khellin in Ammi visnaga seed.

    Science.gov (United States)

    Kamal, Abid; Khan, Washim; Ahmad, Sayeed; Ahmad, F J; Saleem, Kishwar

    2015-01-01

    The present study was used to design simple, accurate and sensitive reversed phase-high-performance liquid chromatography RP-HPLC and high-performance thin-layer chromatography (HPTLC) methods for the development of quantification of khellin present in the seeds of Ammi visnaga. RP-HPLC analysis was performed on a C18 column with methanol: Water (75: 25, v/v) as a mobile phase. The HPTLC method involved densitometric evaluation of khellin after resolving it on silica gel plate using ethyl acetate: Toluene: Formic acid (5.5:4.0:0.5, v/v/v) as a mobile phase. The developed HPLC and HPTLC methods were validated for precision (interday, intraday and intersystem), robustness and accuracy, limit of detection and limit of quantification. The relationship between the concentration of standard solutions and the peak response was linear in both HPLC and HPTLC methods with the concentration range of 10-80 μg/mL in HPLC and 25-1,000 ng/spot in HPTLC for khellin. The % relative standard deviation values for method precision was found to be 0.63-1.97%, 0.62-2.05% in HPLC and HPTLC for khellin respectively. Accuracy of the method was checked by recovery studies conducted at three different concentration levels and the average percentage recovery was found to be 100.53% in HPLC and 100.08% in HPTLC for khellin. The developed HPLC and HPTLC methods for the quantification of khellin were found simple, precise, specific, sensitive and accurate which can be used for routine analysis and quality control of A. visnaga and several formulations containing it as an ingredient.

  11. At-line hyphenation of high-speed countercurrent chromatography with Sephadex LH-20 column chromatography for bioassay-guided separation of antioxidants from vine tea (Ampelopsis grossedentata).

    Science.gov (United States)

    Ma, Ruyi; Zhou, Rongrong; Tong, Runna; Shi, Shuyun; Chen, Xiaoqing

    2017-01-01

    Vine tea (Ampelopsis grossedentata), a widely used healthy tea, beverage and herbal medicine, exhibited strong antioxidant activity. However, systematic purification of antioxidants, especially for those with similar structures or polarities, is a challenging work. Here, we present a novel at-line hyphenation of high-speed countercurrent chromatography with Sephadex LH-20 column chromatography (HSCCC-Sephadex LH-20 CC) for rapid and efficient separation of antioxidants from vine tea target-guided by 1,1-diphenyl-2-picryl-hydrazyl radical-high performance liquid chromatography (DPPH-HPLC) experiment. A makeup pump, a six-port switching valve and a trapping column were served as interface. The configuration had no operational time and mobile phase limitations between two dimensional chromatography and showed great flexibility without tedious sample-handling procedure. Seven targeted antioxidants were firstly separated by stepwise HSCCC using petroleum ether-ethyl acetate-methanol-water (4:9:4:9, v/v/v/v) and (4:9:5:8, v/v/v/v) as solvent systems, and then co-eluted antioxidants were on-line trapped, concentrated and desorbed to Sephadex LH-20 column for further off-line purification by methanol. It is noted that six elucidated antioxidants with purity over 95% exhibited stronger activity than ascorbic acid (VC). More importantly, this at-line hyphenated strategy could sever as a rapid and efficient pathway for systematic purification of bioactive components from complex matrix. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. High-performance liquid chromatography of bile pigments: separation and characterization of the urobilinoids.

    Science.gov (United States)

    Bull, R V; Lim, C K; Gray, C H

    1981-11-20

    The detailed analysis of faecal bile pigments by high-performance liquid chromatography is described. Non-aqueous reversed-phase systems with acetonitrile-dimethyl sulphoxide or acetonitrile-dimethyl sulphoxide-methanol as the mobile phase on C1, C8 or C18-bonded silica are used for the group separation of verdinoids, violinoids and urobilinoids. A silica column, with acetonitrile-water-tetraethylene-pentamine as mobile phase, separates the laevorotatory stercobilin (C33H46N4O6) and half-stercobilin (C33H44N4O6) from the optically inactive urobilin (C33H42N4O6). The diastereoisomers are resolved by converting the urobilinoids into their dimethyl esters before chromatography on a silica column with n-heptane-methyl acetate-methanol containing 1% of diethylamine as the solvent system.

  13. Determination of 1-hydroxypyrene in human urine by high-performance liquid chromatography

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Poulsen, O M; Christensen, J M

    1993-01-01

    A high-performance liquid chromatography (HPLC)/fluorescence method for quantitative analysis of 1-hydroxypyrene in urine was developed. The method validation analysis showed the method to be in analytical control. No significant systematical errors could be demonstrated. The entire run time....... The developed method is presently used for measurement of 1-hydroxypyrene in urine samples from workers exposed to a low airborne level of polycyclic aromatic hydrocarbons, generally less than 25 micrograms/m3. The urine samples of exposed workers (n = 122) showed a range of 1-hydroxypyrene from the limit...... of chromatography was 10 min using isocratic elution (acetonitrile-water, 70:30), and the retention time for 1-hydroxypyrene was 3.5 min. The short run time in combination with the low limit detection (1.37 nmol/L) makes the method potentially applicable for surveillance of pyrene exposure in work environments...

  14. Measuring fuel contamination using high speed gas chromatography and cone penetration techniques

    Energy Technology Data Exchange (ETDEWEB)

    Farrington, S.P.; Bratton, W.L. [Applied Research Associates, Inc., South Royalton, VT (United States); Akard, M.L. [Chromatofast, Inc., Ann Arbor, MI (United States)] [and others

    1995-10-01

    Decision processes during characterization and cleanup of hazardous waste sites are greatly retarded by the turnaround time and expense incurred through the use of conventional sampling and laboratory analyses. Furthermore, conventional soil and groundwater sampling procedures present many opportunities for loss of volatile organic compounds (VOC) by exposing sample media to the atmosphere during transfers between and among sampling devices and containers. While on-site analysis by conventional gas chromatography can reduce analytical turnaround time, time-consuming sample preparation procedures are still often required, and the potential for loss of VOC is not reduced. This report describes the development of a high speed gas chromatography and cone penetration testing system which can detect and measure subsurface fuel contamination in situ during the cone penetration process.

  15. Intact-protein trapping columns for proteomic analysis in capillary high-performance liquid chromatography.

    Science.gov (United States)

    Guan, Xia; Yan, Guoquan; Gao, Mingxia; Hong, Guangfeng; Deng, Chunhui; Zhang, Xiangmin

    2010-10-29

    A new type of monolithic trapping columns with high mechanical strength was prepared by thin-layer sol-gel coating method and applied to trapping intact proteins for on-line capillary liquid chromatography. Monolithic trapping columns were fabricated by entrapping C8 reversed-phase particles into the capillary columns through a sol-gel network, which was formed by hydrolysis and polycondensation of methyltriethoxysilane. Hundreds times of trapping/untrapping for intact proteins were carried out. The trapping columns showed long-term stability up to 300 bar. Recovery, loading capacity and reproducibility of trapping columns were evaluated using four proteins. The recovery of four protein mixtures for the C8 monolithic trapping columns was 99.3% on average. The loading capacity of 5 mm × 320 μm i.d. C8 trapping columns for the protein mixtures was 30 μg. Day-to-day relative standard deviation (RSD) values for recoveries of protein mixtures on the same C8 trapping column ranged from 2.34 to 5.87%, column-to-column RSD values were from 3.01 to 6.81%. The C8 trapping columns were used to trap normal mouse liver intact proteins in a capillary liquid chromatography system. Results demonstrated high efficiency of the monolithic trapping columns for trapping intact proteins for proteomic analysis in on-line capillary liquid chromatography system. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Development of optimized mobile phases for protein separation by high performance thin layer chromatography.

    Science.gov (United States)

    Biller, Julia; Morschheuser, Lena; Riedner, Maria; Rohn, Sascha

    2015-10-09

    In recent years, protein chemistry tends inexorably toward the analysis of more complex proteins, proteoforms, and posttranslational protein modifications. Although mass spectrometry developed quite fast correspondingly, sample preparation and separation of these analytes is still a major issue and quite challenging. For many years, electrophoresis seemed to be the method of choice; nonetheless its variance is limited to parameters such as size and charge. When taking a look at traditional (thin-layer) chromatography, further parameters such as polarity and different mobile and stationary phases can be utilized. Further, possibilities of detection are manifold compared to electrophoresis. Similarly, two-dimensional separation can be also performed with thin-layer chromatography (TLC). As the revival of TLC developed enormously in the last decade, it seems to be also an alternative to use high performance thin-layer chromatography (HPTLC) for the separation of proteins. The aim of this study was to establish an HPTLC separation system that allows a separation of protein mixtures over a broad polarity range, or if necessary allowing to modify the separation with only few steps to improve the separation for a specific scope. Several layers and solvent systems have been evaluated to reach a fully utilized and optimized separation system. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Ultra-High Pressure Fast Size Exclusion Chromatography for Top-Down Proteomics

    Science.gov (United States)

    Chen, Xin; Ge, Ying

    2013-01-01

    Top-down mass spectrometry (MS)-based proteomics has gained a solid growth over the past few years but still faces significant challenges in the liquid chromatographic separation of intact proteins. In top-down proteomics, it is essential to separate the high mass proteins from the low mass species due to the exponential decay in S/N as a function of increasing molecular mass. Size exclusion chromatography (SEC) is a favored liquid chromatography method for size-based separation of proteins but suffers from notoriously low resolution and detrimental dilution. Herein we reported the use of ultra-high pressure (UHP) SEC for rapid and high-resolution separation of intact proteins for top-down proteomics. Fast separation of intact proteins (6 – 669 kDa) was achieved in less than 7 min with high-resolution and high efficiency. More importantly, we have shown that this UHP-SEC provides high-resolution separation of intact proteins using a MS-friendly volatile solvent system, allowing the direct top-down MS analysis of SEC eluted proteins without an additional desalting step. Taken together, we have demonstrated that UHP-SEC is an attractive LC strategy for the size-separation of proteins with great potential for top-down proteomics. PMID:23794208

  18. Analysis of urinary oligosaccharides in lysosomal storage disorders by capillary high-performance anion-exchange chromatography-mass spectrometry

    NARCIS (Netherlands)

    Bruggink, Cees; Poorthuis, Ben J. H. M.; Deelder, André M.; Wuhrer, Manfred

    2012-01-01

    Many lysosomal storage diseases are characterized by an increased urinary excretion of glycoconjugates and oligosaccharides that are characteristic for the underlying enzymatic defect. Here, we have used capillary high-performance anion-exchange chromatography (HPAEC) hyphenated to mass spectrometry

  19. Identifying Natural syNergist from Pongamia pinnata Using High-Speed Counter-Current Chromatography Combined with Isobolographic Analysis

    Directory of Open Access Journals (Sweden)

    Hao Yin

    2017-03-01

    Full Text Available For identifying the synergistic compounds from Pongamia pinnata, an approach based on high-speed counter-current chromatography (HSCCC combined with isobolographic analysis was designed to detect the synergistic effects in the complex mixture [...

  20. Development of new efficient method for isolation of phenolics from sea algae prior to their rapid resolution liquid chromatographic-tandem mass spectrometric determination.

    Science.gov (United States)

    Klejdus, Bořivoj; Plaza, Merichel; Šnóblová, Marie; Lojková, Lea

    2017-02-20

    The extraction of phenolic compounds from 4 different sea algae samples, three brown algae (Cystoseira abies-marina, C. abies-marina grinded under cryogenic conditions with liquid nitrogen, Undaria pinnatifida and Sargassum muticum) and one red algae (Chondrus crispus) via solid phase extraction using micro-elution solid-phase extraction (μ-SPE) plate method was studied. Prior to μ-SPE, 50mg of algae with 80% methanol mixture was extracted in hyphenated series by various extraction techniques, such as pressurized liquid extraction and Ika Ultra-Turrax® Tube Drive, in combination with ultrasound assisted extraction. The μ-SPE plate technique reduced the time of sample pre-treatment thanks to higher sensitivity and pre-concentration effect. Selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic, and syringic acids), hydroxybenzaldehydes (4-hydroxybenzaldehyde, and 3,4-dihydroxybenzaldehyde), and cinnamic acid derivatives (p-coumaric, caffeic, ferulic, sinapic, and chlorogenic acids) were determined using rapid resolution liquid chromatography coupled to mass spectrometry detection with negative ion electrospray ionization (RRLC-ESI-MS) using multiple reactions monitoring. LOQs of measured samples varied in the range 0.23-1.68ng/mL and LODs in the range 0.07-0.52ng/mL. The applied method allowed a simultaneous determination of phenolics (i.e. free, esters soluble in methanol, glycosides, and esters insoluble in methanol) in less than 5min (including alkaline or acidic hydrolysis of raw extracts) from sea algae extracts. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Preparation of Sesquiterpenoids from Tussilago farfara L. by High-speed Counter-current Chromatography.

    Science.gov (United States)

    Cao, Kun; Xu, Yi; Zhao, Tian-Ming; Zhang, Qing

    2016-01-01

    Sesquiterpenoids, such as tussilagone, has effects of raising blood pressure, antiplatelet aggregation, and anti-inflammation activities, which is regarded as index compound for quality control of Tussilago farfara L. This study was aimed to obtain an effective method for fast isolation of sesquiterpenoids from T. farfara L. by high-speed counter-current chromatography (HSCCC). A solvent optimization method for HSCCC was presented, i.e., the separation factors of compounds after the K values of solvent system should be investigated. A ternary solvent system of n-hexane:methanol:water (5:8:2, v/v/v) was selected and applied for the HSCCC, and 56 mg of tussilagone (2) was isolated from T. farfara L., along with two other sesquiterpenoids 5.6 mg of 2,2-dimethyl-6-acetylchromanone (1) and 22 mg of 14-acetoxy-7 β-(3'-ethyl cis-crotonoyloxy)-lα-(2'-methylbutyryloxy)-notonipetranone (3) by HSCCC with high purities. Their chemical structures were elucidated by liquid chromatography-mass spectrometry and nuclear magnetic resonance experiments. These results offered an efficient strategy for preparation of potentially health-relevant phytochemicals from T. farfara L., which might be used for further chemical research and pharmacological studies by preparative HSCCC. The real separation efficiency has been verified by analytical HSCCC.A solvent optimization method for HSCCC was presented and applied to separate and prepare active compounds.A method for rapid and effective separation of target compound Tussilagone with high yield and purity from the flower buds of Tussilago farfara.Two other compounds 2,2-Dimethyl-6-acetylchromanone and 14-acetoxy-7β-(3'-ethyl cis-crotonoyloxy) -lα- (2'-methylbutyryloxy). notonipetranone hasbeen obtained with high purities from flower buds of Tussilago farfara. Abbreviations used: HSCCC: High-Speed Counter-Current Chromatography; LC-MS: Liquid Chromatograph-Mass Spectrometer; NMR: Nuclear Magnetic Resonance; TCM: Traditional Chinese

  2. High-throughput micro-scale cultivations and chromatography modeling: Powerful tools for integrated process development.

    Science.gov (United States)

    Baumann, Pascal; Hahn, Tobias; Hubbuch, Jürgen

    2015-10-01

    Upstream processes are rather complex to design and the productivity of cells under suitable cultivation conditions is hard to predict. The method of choice for examining the design space is to execute high-throughput cultivation screenings in micro-scale format. Various predictive in silico models have been developed for many downstream processes, leading to a reduction of time and material costs. This paper presents a combined optimization approach based on high-throughput micro-scale cultivation experiments and chromatography modeling. The overall optimized system must not necessarily be the one with highest product titers, but the one resulting in an overall superior process performance in up- and downstream. The methodology is presented in a case study for the Cherry-tagged enzyme Glutathione-S-Transferase from Escherichia coli SE1. The Cherry-Tag™ (Delphi Genetics, Belgium) which can be fused to any target protein allows for direct product analytics by simple VIS absorption measurements. High-throughput cultivations were carried out in a 48-well format in a BioLector micro-scale cultivation system (m2p-Labs, Germany). The downstream process optimization for a set of randomly picked upstream conditions producing high yields was performed in silico using a chromatography modeling software developed in-house (ChromX). The suggested in silico-optimized operational modes for product capturing were validated subsequently. The overall best system was chosen based on a combination of excellent up- and downstream performance. © 2015 Wiley Periodicals, Inc.

  3. [Determination of succinic acid in desvenlafaxine succinate by high performance ion-exclusion chromatography and high performance ion-exchange chromatography].

    Science.gov (United States)

    Zong, Yanping; Li, Jinghua; Sun, Wei; Liu, Guixia; Lu, Jinghua; Shan, Guangzhi

    2016-02-01

    New methods were developed for the determination of succinic acid in desvenlafaxine succinate (DVS) by high performance ion-exclusion chromatography (HPIEC) and high performance ion-exchange chromatography (HPIC). HPIEC and HPIC methods were used separately to determinate the succinic acid in DVS. With HPIEC, the sample was diluted with 2. 50 x 10(-3) mol/L sulfuric acid solution and filtrated by 0. 22 µm polyether sulfone filter membrane, and then analyzed by HPIEC directly without any further pretreatment. The analytical column was Phenomenex Rezex ROA-organic Acid H+(8%) (300 mmx7. 8 mm). The mobile phase was 2. 50x10(-3) mol/L sulfuric acid solution at the flow rate of 0. 5 mL/min. The column temperature was set at 40 °C, and the detection wavelength was 210 nm. The injection volume was 10 KL. The assay was quantified by external standard method. With HPIC, the sample was diluted with ultrapure water and filtrated by 0. 22 µm polyether sulfone filter membrane, and then analyzed by HPIC directly without any further pretreatment. The analytical column was Dionex IonPac AS11-HC (250 mm x 4 mm) with a guard column IonPacAG11-HC (50 mm x 4 mm). Isocratic KOH elute generator was used at the flow rate of 1. 0 mL/min. The detection was performed by a Dionex suppressed (DIONEX AERS 500 4-mm) conductivity detector. The injection volume was 10 µL. The content computation was performed with peak area external reference method. The results of HPIEC method for succinic acid were 28. 8%, 28. 9% and 28. 9%, while the results of HPIEC method were 28. 2%, 28. 6% and 28. 6%. The results of HPIEC and HPIC methods were not significantly different. The two methods can both be used to determine the contents of succinic acid in DVS. The surveillance analytical method should be chosen according to the situation.

  4. Comprehensive separation and identification of chemical constituents from Apocynum venetum leaves by high-performance counter-current chromatography and high performance liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Zhang, Yuchi; Liu, Chunming; Zhang, Zhengkun; Wang, Jing; Wu, Guimei; Li, Sainan

    2010-11-15

    High-performance counter-current chromatography (HPCCC) and high performance liquid chromatography coupled with mass spectrometry (HPLC-MS) was efficiently utilized for the separation and identification of the chemical components with a wide range of polarity from the mixed extract of Chinese medicinal herb Apocynum venetum. For HPCCC separation, four sets of solvent systems, n-hexane-ethyl acetate-acetonitrile-water (1.5:3.5:2:4.5, v:v:v:v), ethyl acetate-methanol-water (5:2:5, v:v:v) and n-butanol-methanol-water (5:1:5, v:v:v) were used for the one-step separation by four stages. The HPCCC separation was initiated by filling the column with the lower phase of n-hexane-ethyl acetate-acetonitrile-water (1.5:3.5:2:5, v:v:v:v) as a stationary phase followed by elution with the upper phase of n-hexane-ethyl acetate-acetonitrile-water (1.5:3.5:2:5, v:v:v:v) to separate the hydrophobic compounds (tail to head). Then the mobile phase was switched to the upper phase of ethyl acetate-acetonitrile-water (5:3:7, v:v:v) to eluted the moderate hydrophobic compounds, then the mobile phase was switched to the upper phase of ethyl acetate-methanol-water (5:2:5, v:v:v) to eluted the moderate hydrophilic compounds, and finally the hydrophilic compounds still retained in the column was eluted by the upper phase of n-butanol-methanol-water (5:1:5, v:v:v). A total of 16 named compounds including adhyperforin, hyperforin, amentoflavone, biapigenin, quercetin, avicularin, acetylated isoquercetin, acetylated hyperoside, astragalin, trifolin, isoquercetin, hyperoside, querciturone, rutin, chlorogenic acid and quercetin-3-O-β-D-glucosyl-β-D-glucopyranoside were successfully separated via the four sets of solvent systems in one step operation for 130 min. The compounds separated by HPCCC were identified by comparing with mixed standards data of HPLC-MS as well as NMR data. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  5. Detection of cheese whey and caseinomacropeptide in fermented milk beverages using high performance liquid chromatography

    OpenAIRE

    E.H.P. Andrade; M.R. Souza; L.M. Fonseca; C.F.A.M. Penna; M.M.O.P. Cerqueira; T. Roza; B. Seridan; M.F.S. Resende; F.A. Pinto; C.N.B.C. Villanoeva; M.O. Leite

    2014-01-01

    Cheese whey level and caseinomacropeptide (CMP) index of fermented milk beverages added with four levels of cheese whey (0, 10, 20, and 40%) and stored at 8-10oC for 0, 7, 14 and 21 days were determined by high performance liquid chromatography-gel filtration (HPLC-GF). Additionally, the interference of the starter culture and the storage time on the detection of cheese whey and CMP were investigated. Refrigerated storage up to 21 days did not affect (P>0.05) cheese whey and CMP amounts in mi...

  6. Study of Saiga Horn Using High-Performance Liquid Chromatography with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kateřina Mikulíková

    2012-01-01

    Full Text Available The saiga horns have been investigated the using of modern analytic methods. High-performance liquid chromatography (HPLC with mass-spectrometric (MS and MS/MS detection and polyacrylamide gel electrophoresis (PAGE were used. It could be concluded that basic proteins of the saiga horns are keratins and collagen. The basic representation protein in all samples is keratin type I microfibrillar (from sheep, keratin type II microfibrillar (from sheep, collagen type I (α1 (from bovine and collagen type I (α2 (from bovine. Free amino acids we determined in all samples are nontreated by enzyme.

  7. Quantitative analysis of benzodiazepines in vitreous humor by high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Elham Bazmi

    2016-08-01

    Full Text Available Objective: Benzodiazepines are frequently screened drugs in emergency toxicology, drugs of abuse testing, and in forensic cases. As the variations of benzodiazepines concentrations in biological samples during bleeding, postmortem changes, and redistribution could be biasing forensic medicine examinations, hence selecting a suitable sample and a validated accurate method is essential for the quantitative analysis of these main drug categories. The aim of this study was to develop a valid method for the determination of four benzodiazepines (flurazepam, lorazepam, alprazolam, and diazepam in vitreous humor using liquid–liquid extraction and high-performance liquid chromatography. Methods: Sample preparation was carried out using liquid–liquid extraction with n-hexane: ethyl acetate and subsequent detection by high-performance liquid chromatography method coupled to diode array detector. This method was applied to quantify benzodiazepines in 21 authentic vitreous humor samples. Linear curve for each drug was obtained within the range of 30–3000 ng/mL with coefficient of correlation higher than 0.99. Results: The limit of detection and quantitation were 30 and 100 ng/mL respectively for four drugs. The method showed an appropriate intra- and inter-day precision (coefficient of variation < 10%. Benzodiazepines recoveries were estimated to be over 80%. The method showed high selectivity; no additional peak due to interfering substances in samples was observed. Conclusion: The present method was selective, sensitive, accurate, and precise for the quantitative analysis of benzodiazepines in vitreous humor samples in forensic toxicology laboratory.

  8. Biointeraction analysis of carbamazepine binding to alpha1-acid glycoprotein by high-performance affinity chromatography.

    Science.gov (United States)

    Xuan, Hai; Joseph, K S; Wa, Chunling; Hage, David S

    2010-08-01

    Interactions of the drug carbamazepine with the serum protein alpha(1)-acid glycoprotein (AGP) were examined by high-performance affinity chromatography. Frontal analysis studies with an immobilized AGP column and control column indicated carbamazepine had both low-affinity interactions with the support and high-affinity interactions with AGP. When a correction was made for binding to the support, the association equilibrium constant measured at pH 7.4 and 37 degrees C for carbamazepine with AGP was 1.0 (+/-0.1) x 10(5) M(-1), with values that ranged from 5.1 to 0.58 x 10(5) M(-1) in going from 5 to 45 degrees C. It was found in competition studies that these interactions were occurring at the same site that binds propranolol on AGP. Temperature studies indicated that the change in enthalpy was the main driving force for the binding of carbamazepine to AGP. These results provide a more complete picture of how carbamazepine binds to AGP in serum. This report also illustrates how high-performance affinity chromatography can be used to examine biological interactions and drug-protein binding in situations in which significant interactions for an analyte are present with both the chromatographic support and an immobilized ligand.

  9. Detailed analysis of petroleum hydrocarbon attenuation in biopiles by high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography.

    Science.gov (United States)

    Mao, Debin; Lookman, Richard; Van De Weghe, Hendrik; Van Look, Dirk; Vanermen, Guido; De Brucker, Nicole; Diels, Ludo

    2009-02-27

    Enhanced bioremediation of petroleum hydrocarbons in two biopiles was quantified by high-performance liquid chromatography (HPLC) followed by comprehensive two-dimensional gas chromatography (GCXGC). The attenuation of 34 defined hydrocarbon classes was calculated by HPLC-GCXGC analysis of representative biopile samples at start-up and after 18 weeks of biopile operation. In general, a-cyclic alkanes were most efficiently removed from the biopiles, followed by monoaromatic hydrocarbons. Cycloalkanes and polycyclic aromatic hydrocarbons (PAHs) were more resistant to degradation. A-cyclic biomarkers farnesane, trimethyl-C13, norpristane, pristane and phytane dropped to only about 10% of their initial concentrations. On the other hand, C29-C31 hopane concentrations remained almost unaltered after 18 weeks of biopile operation, confirming their resistance to biodegradation. They are thus reliable indicators to estimate attenuation potential of petroleum hydrocarbons in biopile processed soils.

  10. Determination of muscimol and ibotenic acid in Amanita mushrooms by high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Tsujikawa, Kenji; Kuwayama, Kenji; Miyaguchi, Hajime; Kanamori, Tatsuyuki; Iwata, Yuko; Inoue, Hiroyuki; Yoshida, Takemi; Kishi, Tohru

    2007-06-01

    A reliable analytical method was developed for the quantification and identification of muscimol (MUS) and ibotenic acid (IBO), the toxic constituents of Amanita muscaria and Amanita pantherina. MUS and IBO were extracted from mushrooms by aqueous methanol and derivatized with dansyl chloride (DNS-Cl). After extraction with ethyl acetate and evaporation of the solvent, the residue was ethylated with 1.25 M hydrogen chloride in ethanol. The resulting derivatives were quantified by high-performance liquid chromatography with UV detection and identified by liquid chromatography electrospray ionization tandem mass spectrometry. Calibration curves were linear in the range of 25-2500 ppm for MUS and 40-2500 ppm for IBO, respectively. This method was successfully applied to identify and quantify MUS and IBO in Amanita mushrooms naturally grown and circulated in the drug market.

  11. Development and validation of ultra-high performance supercritical fluid chromatography method for determination of illegal dyes and comparison to ultra-high performance liquid chromatography method.

    Science.gov (United States)

    Khalikova, Maria A; Šatínský, Dalibor; Solich, Petr; Nováková, Lucie

    2015-05-18

    A novel simple, fast and efficient ultra-high performance supercritical fluid chromatography (UHPSFC) method was developed and validated for the separation and quantitative determination of eleven illegal dyes in chili-containing spices. The method involved a simple ultrasound-assisted liquid extraction of illegal compounds with tetrahydrofuran. The separation was performed using a supercritical fluid chromatography system and CSH Fluoro-Phenyl stationary phase at 70°C. The mobile phase was carbon dioxide and the mixture of methanol:acetonitrile (1:1, v/v) with 2.5% formic acid as an additive at the flow rate 2.0 mL min(-1). The UV-vis detection was accomplished at 500 nm for seven compounds and at 420 nm for Sudan Orange G, Butter Yellow, Fast Garnet GBC and Methyl Red due to their maximum of absorbance. All eleven compounds were separated in less than 5 min. The method was successfully validated and applied using three commercial samples of chili-containing spices - Chili sauce (Indonesia), Feferony sauce (Slovakia) and Mojo sauce (Spain). The linearity range of proposed method was 0.50-9.09 mg kg(-1) (r ≥ 0.995). The detection limits were determined as signal to noise ratio of 3 and were ranged from 0.15 mg kg(-1) to 0.60 mg kg(-1) (1.80 mg kg(-1) for Fast Garnet) for standard solution and from 0.25 mg kg(-1) to 1.00 mg kg(-1) (2.50 mg kg(-1) for Fast Garnet, 1.50 mg kg(-1) for Sudan Red 7B) for chili-containing samples. The recovery values were in the range of 73.5-107.2% and relative standard deviation ranging from 0.1% to 8.2% for within-day precision and from 0.5% to 8.8% for between-day precision. The method showed potential for being used to monitor forbidden dyes in food constituents. The developed UHPSFC method was compared to the UHPLC-UV method. The orthogonality of Sudan dyes separation by these two methods was demonstrated. Benefits and drawbacks were discussed showing the reliability of both methods for monitoring of studied illegal dyes in real

  12. A simple dual online ultra-high pressure liquid chromatography system (sDO-UHPLC) for high throughput proteome analysis.

    Science.gov (United States)

    Lee, Hangyeore; Mun, Dong-Gi; Bae, Jingi; Kim, Hokeun; Oh, Se Yeon; Park, Young Soo; Lee, Jae-Hyuk; Lee, Sang-Won

    2015-08-21

    We report a new and simple design of a fully automated dual-online ultra-high pressure liquid chromatography system. The system employs only two nano-volume switching valves (a two-position four port valve and a two-position ten port valve) that direct solvent flows from two binary nano-pumps for parallel operation of two analytical columns and two solid phase extraction (SPE) columns. Despite the simple design, the sDO-UHPLC offers many advantageous features that include high duty cycle, back flushing sample injection for fast and narrow zone sample injection, online desalting, high separation resolution and high intra/inter-column reproducibility. This system was applied to analyze proteome samples not only in high throughput deep proteome profiling experiments but also in high throughput MRM experiments.

  13. Triacylglycerol profiling of microalgae strains for biofuel feedstock by liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    MacDougall, Karen M; McNichol, Jesse; McGinn, Patrick J; O'Leary, Stephen J B; Melanson, Jeremy E

    2011-11-01

    Biofuels from photosynthetic microalgae are quickly gaining interest as a viable carbon-neutral energy source. Typically, characterization of algal feedstock involves breaking down triacylglycerols (TAG) and other intact lipids, followed by derivatization of the fatty acids to fatty acid methyl esters prior to analysis by gas chromatography (GC). However, knowledge of the intact lipid profile could offer significant advantages for discovery stage biofuel research such as the selection of an algal strain or the optimization of growth and extraction conditions. Herein, lipid extracts from microalgae were directly analyzed by ultra-high pressure liquid chromatography-mass spectrometry (UHPLC-MS) using a benchtop Orbitrap mass spectrometer. Phospholipids, glycolipids, and TAGs were analyzed in the same chromatographic run, using a combination of accurate mass and diagnostic fragment ions for identification. Using this approach, greater than 100 unique TAGs were identified over the six algal strains studied and TAG profiles were obtained to assess their potential for biofuel applications. Under the growth conditions employed, Botryococcus braunii and Scenedesmus obliquus yielded the most comprehensive TAG profile with a high abundance of TAGs containing oleic acid.

  14. Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee

    Directory of Open Access Journals (Sweden)

    Carolina Schaper Bizzotto

    2013-03-01

    Full Text Available Decaffeinated coffee accounts for 10 percent of coffee sales in the world; it is preferred by consumers that do not wish or are sensitive to caffeine effects. This article presents an analytical comparison of capillary electrophoresis (CE and high performance liquid chromatography (HPLC methods for residual caffeine quantification in decaffeinated coffee in terms of validation parameters, costs, analysis time, composition and treatment of the residues generated, and caffeine quantification in 20 commercial samples. Both methods showed suitable validation parameters. Caffeine content did not differ statistically in the two different methods of analysis. The main advantage of the high performance liquid chromatography (HPLC method was the 42-fold lower detection limit. Nevertheless, the capillary electrophoresis (CE detection limit was 115-fold lower than the allowable limit by the Brazilian law. The capillary electrophoresis (CE analyses were 30% faster, the reagent costs were 76.5-fold, and the volume of the residues generated was 33-fold lower. Therefore, the capillary electrophoresis (CE method proved to be a valuable analytical tool for this type of analysis.

  15. Hb A1c Separation by High Performance Liquid Chromatography in Hemoglobinopathies

    Directory of Open Access Journals (Sweden)

    Vani Chandrashekar

    2016-01-01

    Full Text Available Hb A1c measurement is subject to interference by hemoglobin traits and this is dependent on the method used for determination. In this paper we studied the difference between Hb A1c measured by HPLC in hemoglobin traits and normal chromatograms. We also studied the correlation of Hb A1c with age. Hemoglobin analysis was carried out by high performance liquid chromatography. Spearman’s rank correlation was used to study correlation between A1c levels and age. Mann-Whitney U test was used to study the difference in Hb A1c between patients with normal hemoglobin and hemoglobin traits. A total of 431 patients were studied. There was positive correlation with age in patients with normal chromatograms only. No correlation was seen in Hb E trait or beta thalassemia trait. No significant difference in Hb A1c of patients with normal chromatograms and patients with hemoglobin traits was seen. There is no interference by abnormal hemoglobin in the detection of A1c by high performance liquid chromatography. This method cannot be used for detection of A1c in compound heterozygous and homozygous disorders.

  16. High-performance liquid chromatography mass spectrometry of gold and alloy clusters protected by hydrophilic thiolates.

    Science.gov (United States)

    Niihori, Yoshiki; Shima, Daisuke; Yoshida, Kana; Hamada, Kota; Nair, Lakshmi V; Hossain, Sakiat; Kurashige, Wataru; Negishi, Yuichi

    2018-01-25

    In this work, we found two hydrophilic interaction liquid chromatography (HILIC) columns for high-performance liquid chromatography (HPLC) suitable for the high-resolution separation of hydrophilic metal clusters. The mass distributions of the product mixtures of hydrophilic metal clusters were evaluated via HPLC mass spectrometry (LC/MS) using these HILIC columns. Consequently, we observed multiple clusters that had not been previously reported for glutathionate (SG)-protected gold clusters (Aun(SG)m). Additionally, we demonstrated that Aun-xMx(SG)m alloy clusters (M = Ag, Cu, or Pd) in which part of the Au in the Aun(SG)m cluster is replaced by a heteroelement can be synthesized, similar to the case of hydrophobic alloy clusters. It is easy to evaluate the mass distributions of hydrophilic metal clusters using this method. Thus, remarkable progress in the synthesis techniques of hydrophilic metal clusters through the use of this method is anticipated, as is the situation for hydrophobic metal clusters.

  17. Triacylglycerol profiling of microalgae strains for biofuel feedstock by liquid chromatography-high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, Karen M.; McNichol, Jesse; McGinn, Patrick J.; O' Leary, Stephen J.B.; Melanson, Jeremy E. [Institute for Marine Biosciences, National Research Council of Canada, Halifax, NS (Canada)

    2011-11-15

    Biofuels from photosynthetic microalgae are quickly gaining interest as a viable carbon-neutral energy source. Typically, characterization of algal feedstock involves breaking down triacylglycerols (TAG) and other intact lipids, followed by derivatization of the fatty acids to fatty acid methyl esters prior to analysis by gas chromatography (GC). However, knowledge of the intact lipid profile could offer significant advantages for discovery stage biofuel research such as the selection of an algal strain or the optimization of growth and extraction conditions. Herein, lipid extracts from microalgae were directly analyzed by ultra-high pressure liquid chromatography-mass spectrometry (UHPLC-MS) using a benchtop Orbitrap mass spectrometer. Phospholipids, glycolipids, and TAGs were analyzed in the same chromatographic run, using a combination of accurate mass and diagnostic fragment ions for identification. Using this approach, greater than 100 unique TAGs were identified over the six algal strains studied and TAG profiles were obtained to assess their potential for biofuel applications. Under the growth conditions employed, Botryococcus braunii and Scenedesmus obliquus yielded the most comprehensive TAG profile with a high abundance of TAGs containing oleic acid. (orig.)

  18. Preparative Separation of Phenolic Compounds from Halimodendron halodendron by High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Zhu Yu

    2010-08-01

    Full Text Available Three phenolic compounds, p-hydroxybenzoic acid (1, isorhamnetin-3-O-β-D-rutinoside (2, and 3,3'-di-O-methylquercetin (5, along with a phenolic mixture were successfully separated from the ethyl acetate crude extract of Halimodendron halodendron by high-speed counter-current chromatography (HSCCC with chloroform-methanol-water-acetic acid (4:3:2:0.05, v/v as the two-phase solvent system. The phenolic mixture from HSCCC was further separated by preparative HPLC and purified by Sephadex LH-20 to afford quercetin (3 and 3-O-methylquercetin (4. Seven hundred mg of ethyl acetate crude extract was separated by HSCCC to obtain six fractions which were then analyzed by high performance liquid chromatography (HPLC. The HSCCC separation obtained total of 80 mg of the mixture of quercetin (3 and 3-O-methylquercetin (4 (26.43% and 71.89%, respectively in fraction 2, 14 mg of 3,3'-di-O-methylquercetin (5 at 95.14% of purity in fraction 3, 15 mg of p-hydroxybenzoic acid (1 at 92.83% of purity in fraction 5, 12 mg of isorhamnetin-3-O-β-D-rutinoside (2 at 97.99% of purity in fraction 6. This is the first time these phenolic compounds have been obtained from H. halodendron, and their chemical structures identified by means of physicochemical and spectrometric analysis.

  19. Development of high performance liquid chromatography method for miconazole analysis in powder sample

    Science.gov (United States)

    Hermawan, D.; Suwandri; Sulaeman, U.; Istiqomah, A.; Aboul-Enein, H. Y.

    2017-02-01

    A simple high performance liquid chromatography (HPLC) method has been developed in this study for the analysis of miconazole, an antifungal drug, in powder sample. The optimized HPLC system using C8 column was achieved using mobile phase composition containing methanol:water (85:15, v/v), a flow rate of 0.8 mL/min, and UV detection at 220 nm. The calibration graph was linear in the range from 10 to 50 mg/L with r 2 of 0.9983. The limit of detection (LOD) and limit of quantitation (LOQ) obtained were 2.24 mg/L and 7.47 mg/L, respectively. The present HPLC method is applicable for the determination of miconazole in the powder sample with a recovery of 101.28 % (RSD = 0.96%, n = 3). The developed HPLC method provides short analysis time, high reproducibility and high sensitivity.

  20. Denaturing high performance liquid chromatography (DHPLC in detection of microsatellite instability

    Directory of Open Access Journals (Sweden)

    Metka Ravnik-Glavač

    2007-12-01

    Full Text Available Background: Microsatellite instability (MSI is a phenomenon characterized by small deletions or insertions within short tandem repeats in tumour DNA compared to matching normal DNA. MSI analysis is becoming more and more important for detection of hereditary non-polyposis colorectal cancer as well as for sporadic primary colorectal tumours with MSI high phenotype. Use of five quasimonomorphic mononucleotide markers eliminates ultimate need for analysis of germline DNA corresponding to tumour DNA. Here we discuss our method for MSI analysis using denaturating high performance liquid chromatography (DHPLC in combination with quasimonomorphic mononucleotide microsatellite markers in comparison with previously used methods. The method is high-throughput, accurate, quick and cost-effective and suitable for large-scale studies as well as for daily use with smaller numbers of samples.

  1. One-pot preparation of a novel monolith for high performance liquid chromatography applications.

    Science.gov (United States)

    Jiao, Xiaoyan; Shen, Shigang; Shi, Tiesheng

    2015-12-15

    Various novel porous organic-based monoliths with the mode of hydrophobicity were synthesized by in situ free-radical crosslinking copolymerization and optimized for the separations of small molecules and high-performance reversed-phase chromatography (RP-chromatography). These monoliths contained co-polymers based on glycidyl methacrylate (GMA)/ethylene glycol dimethacrylate (EDMA)/tripropylene glycol diacrylate (TPGDA) or EDMA/TPGDA. A mixture of cetanol, methanol and poly (ethylene glycol) (PEG) was used as the porogen, with the ratio of these solvents being varied along with the polymerization temperature to generate a library of monoliths. The conditions were optimized and the resulting poly (GMA-co-TPGDA-co-EDMA) monolith was investigated by infrared spectrometer (IR), field emission scanning electron microscope (FESEM), and mercury intrusion porosimetry (MIP), respectively. The column performance was assessed by the separation of a series of neutral solutes of benzene derivatives. The result demonstrated that the prepared monolith exhibited an RP-chromatographic behavior and relatively homogeneous structure, good permeability and separation performance. Moreover, the relative standard deviations (RSDs) of the retention factor values for benzene derivatives were less than 1.5% (n=7, column-to-column). The approach used in this study was extended to the separation of anilines. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Metabolic profiling assisted quality assessment of Rhodiola rosea extracts by high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Zhanguo; Hu, Huiling; Chen, Fang; Zou, Liang; Yang, Mingfu; Wang, Anqi; Foulsham, James E; Lan, Ke

    2012-05-01

    In this work, fast and sensitive high-performance liquid chromatography (HPLC) coupled with multivariate analysis was utilized to assist the quality assessment of Rhodiola rosea extracts (RREs). 131 peaks were separated and detected in RREs on a fused-core C18 column. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the chromatographic data demonstrated that 10 batches of RREs could be well-differentiated and categorized into three groups which were closely related to the origins of RREs. Partial least square-discriminant analysis (PLS-DA) showed that the quality differentiation might be explained by at least 6 components, in which rosavin was characterized by an external reference, rosiridine was identified by liquid chromatography-mass spectrometry (LC-MS), and the mass spectra of the others were provided. The observation that the level of rosavin was more relevant to the multivariate chromatographic data than the ones of salidroside and tyrosol, the other two components commonly used to standardize RREs, was confirmed by the PLS prediction models. Results of the present study not only indicated that rosavin was a rational marker to represent the quality of RREs, but also demonstrated the power of HPLC-based metabolic profiling in the quality assessment of herbal extracts. © Georg Thieme Verlag KG Stuttgart · New York.

  3. [Estimation of chloramphenicol in the working area air by high performance liquid chromatography].

    Science.gov (United States)

    Kristova-Bagdasarian, V L; Chokhadzhieva, D

    2008-01-01

    Chloramphenicol (levomycetin) is a broad-spectrum antibiotic that is active against gram-positive and gram-negative microorganisms. At present, it is manufactured via organic synthesis. Working place air becomes polluted during the manufacture and use of medicines containing chloramphenicol. In the working place air, chloramphenicol is present as a disintegration aerosol and may provoke occupational diseases of varying severity in the exposed persons. A procedure has been determined to measure air chloramphenicol, by using high performance liquid chromatography. Aspiration through an AFA FPP-15 aerosol filter is a suitable device for air chloramphenicol sampling. The selected chloramphenicol is removed from the filter via triple methanol extraction in an ultrasound bath. The pooled extract is evaporated to dryness in a current of nitrogen and the dry residue is dissolved in the mobile phase containing acetonitrile : buffer (pH 4.8) = 30:70. The chloramphenicol determination procedure using reverse-phase liquid chromatography with ultraviolet detection at a wavelength of 275 nm has been developed and completely validated. Chromatographic conditions are given. The retention time of chloramphenicol is 6.5 min. The detection limit is 0.1 microg/cm3. The method is noted for a linear relationship between the concentration of chloramphenicol (microg/cm3) and the peak area (mm2) in the range of 1 to 20 microg/cm3.

  4. Validation of a technique by high-performance liquid chromatography for the determination of total isoflavones

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    Pilar A. Soledispa Cañarte

    2017-04-01

    Full Text Available Context: Isoflavones may act as selective regulators in the prevention of various diseases. The most important source of isoflavones is the soy, from which different phytotherapeutics are elaborated of use in Ecuadorian population. However, its concentration varies depending on several factors, therefore quality assessment need to be carried out through out several analytical methods. Aims: To validate an analytical method by high precision liquid chromatography (HPLC to quantify total isoflavones in herbal medicine. Methods: To quantify isoflavones, it was used a brand liquid chromatography with UV/VIS detector at 260 nm, C-18 column using isocratic method. The mobile phase was composed of 2% acetic acid: acetonitrile (75:25. The quantification was performed against reference standard. The parameters for the validation followed the established in the USP 33. Results: The chromatogram presented six peaks with elution between 1.557 and 18.913 min. The linearity of the system and the method got r2 equal to 0.98 and 0.99 respectively. The coefficients of variation 1.5% in the study of repetitiveness and 2% in intermediate precision. The accuracy of the adjusted lineal model exhibited r=0.95 and intercept reliable interval (-0.921; 1.743. Conclusions: The validated method was specific, accurate, precise and linear. It can be used for quality control and stability studies of isoflavones present in herbal medicine.

  5. Separation of Aliphatic and Aromatic Carboxylic Acids by Conventional and Ultra High Performance Ion Exclusion Chromatography.

    Science.gov (United States)

    Mansour, Fotouh R; Kirkpatrick, Christine L; Danielson, Neil D

    2013-06-01

    An ion exclusion chromatography (IELC) comparison between a conventional ion exchange column and an ultra-high performance liquid chromatography (UHPLC) dynamically surfactant modified C18 column for the separation of an aliphatic carboxylic acid and two aromatic carboxylic acids is presented. Professional software is used to optimize the conventional IELC separation conditions for acetylsalicylic acid and the hydrolysis products: salicylic acid and acetic acid. Four different variables are simultaneously optimized including H 2 SO 4 concentration, pH, flow rate, and sample injection volume. Thirty different runs are suggested by the software. The resolutions and the time of each run are calculated and feed back to the software to predict the optimum conditions. Derringer's desirability functions are used to evaluate the test conditions and those with the highest desirability value are utilized to separate acetylsalicylic acid, salicylic acid, and acetic acid. These conditions include using a 0.35 m M H 2 SO 4 (pH 3.93) eluent at a flow rate of 1 mL min -1 and an injection volume of 72 μL. To decrease the run time and improve the performance, a UHPLC C18 column is used after dynamic modification with sodium dodecyl sulfate. Using pure water as a mobile phase, a shorter analysis time and better resolution are achieved. In addition, the elution order is different from the IELC method which indicates the contribution of the reversed-phase mode to the separation mechanism.

  6. Analysis of sulfonated compounds by ion-exchange high-performance liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Socher, G; Nussbaum, R; Rissler, K; Lankmayr, E

    2001-03-30

    Ion-exchange high-performance liquid chromatography (HPIEC)-mass spectrometry (MS) was used for the analysis of different sulfonated compounds. HPIEC was performed on an aminopropyl column applying a gradient with increasing concentration of a buffer consisting of ammonium acetate-acetic acid and acetonitrile as the organic modifier. HPIEC is well suited to highly efficient separation of sulfonated compounds and furthermore, due to the volatility of ammonium acetate, the method is also appropriate for LC-MS coupling by the means of either atmospheric pressure chemical ionization or electrospray ionization. The applicability range of HPIEC-MS is demonstrated on the basis of a complex mixture of model substances consisting of sulfonated aromatics and textile dyes largely differing from each other in their structural properties.

  7. Determination of carbohydrates by high performance anion chromatography-pulsed amperometric detection in mushrooms.

    Science.gov (United States)

    Zhou, Shuai; Tang, Qingjiu; Luo, Xi; Xue, Jun-Jie; Liu, Yanfang; Yang, Yan; Zhang, Jingsong; Feng, Na

    2012-01-01

    A method of detecting carbohydrates (fucose, trehalose, mannitol, arabitol, mannose, glucose, galactose, fructose, and ribose) by high-performance anion chromatography-pulsed amperometric detection (HAPEC-PAD) was established. The conditions are: CarboPac MA1 column, NaOH as the eluent, temperature 30°C, Au working electrode, Ag/AgCl reference electrode, and flow rate 0.4 mL/min. These nine analytes, which yielded high resolution by this method, could be detected in 40 minutes. Mushrooms were tested and good precision, stability, and reproducibility were achieved. This method is suitable for mushroom samples and could support research and development on sugar and sugar alcohol, which contains special effects.

  8. Rifampicin Interference in the Measurement of Urinary Catecholamines by High-Performance Liquid Chromatography.

    Science.gov (United States)

    Kim, Hyun-Ki; Ko, Dae-Hyun; Jeong, Tae-Dong; Lee, Sang-Hee; Lee, Woochang; Lee, Soo-Youn; Chun, Sail; Song, Junghan; Min, Won-Ki

    2015-01-01

    Measurement of urine and plasma catecholamines and their metabolites are essential for the diagnosis of pheochromocytoma. Here, we report our experience of rifampicin interference in the measurement of urinary catecholamines using high-performance liquid chromatography. During a 1-year period, four patients taking rifampicin showed unusual chromatograms with markedly larger norepinephrine spikes, translating to highly elevated norepinephrine concentrations: 290.2, 720.1, 312.0, and 812.7 μg/L. This interference effect did not occur when samples were prepared using the alumina method, with norepinephrine values decreasing to 26.4, 31.5, 21.9, and 17.2 μg/L. Interference was also absent in data using LC-MS/MS. Clinical laboratories should verify whether rifampicin interferes with test results in their assays, and physicians should be informed that urinary norepinephrine levels can be falsely elevated in patients taking rifampicin. © 2015 by the Association of Clinical Scientists, Inc.

  9. Melatonin in edible plants identified by radioimmunoassay and by high performance liquid chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dubbels, R.; Klenke, E.; Schnakenberg, E.; Ehlers, C.; Schloot, W. [Univ. of Bremen, Center of Human Genetics and Genetic Counselling, Bremen (Germany); Reiter, R.J. [The Univ. of Texas Health Science Center at San Antonio, Dept. of Cellular and Structural Biology, San Antonio, Texas (United States); Goebel, A.; Schiware, H.W. [Gemeinschaftslabor Dr. Schiwara et al., Breman (Germany)

    1995-01-01

    Melatonin, the chief hormone of the pineal gland in vertebrates, is widely distributed in the animal kingdom. Among many functions, melatonin synchronizes circadian and circannual rhythms, stimulates immune function, may increase life span, inhibits growth of cancer cells in vitro and cancer progression and promotion in vivo, and was recently shown to be a potent hydroxyl radical scavenger and antioxidant. Hydroxyl radicals are highly toxic by-products of oxygen metabolism that damage cellular DNA and other macromolecules. Herein we report that melatonin, in varying concentrations, is also found in a variety of plants. Melatonin concentrations, measured in nine different plants by radioimmunoassay, ranged from 0 to 862 pg melatonin/mg protein. The presence of melatonin was verified by gas chromatography/mass spectrometry. Our findings suggest that the consumption of plant materials that contain high levels of melatonin could alter blood melatonin levels of the indole as well as provide protection of macromolecules against oxidative damage. (au) 30 refs.

  10. Evaluation of nanoflow liquid chromatography high resolution mass spectrometry for pesticide residue analysis in food.

    Science.gov (United States)

    Moreno-González, David; Pérez-Ortega, Patricia; Gilbert-López, Bienvenida; Molina-Díaz, Antonio; García-Reyes, Juan F; Fernández-Alba, Amadeo R

    2017-08-25

    This article reports on the evaluation of nanoflow liquid chromatography-mass spectrometry (LC-MS) for pesticide residue analysis in food. The approach is based on the use of reversed-phase C18nano columns with an integrated emitter, so that separation, ionization and detection are performed minimizing dead volumes. The use of nanoflow not only increases ionization efficiency and minimizes ionization suppression but also boost sensitivity compared to analytical-scale LC-MS methods. The nanoflow LC system was combined with full-scan high resolution mass spectrometry using a Q-Exactive Orbitrap instrument. The analytical performance was assessed for over 60 representative pesticides in five representative commodities (tomato, baby food, orange, fruit-based jam and olive oil). The sensitivity achieved with this configuration enables the implementation of high dilution factors (eg. 1:20, 1:50 or beyond) in pesticide residue workflows without compromising sensitivity, featuring limits of quantitation in the low ng kg-1 range. Using this dilution factors, signal suppression was found negligible in most cases (<10% in most cases, especially with 1:50 dilution), so that matrix-matched standards may be skipped, thus simplifying laboratory workflows. The robustness of the nanoflow LC system and its capability to withstand long analytical runs was also evaluated. Appropriate precision in terms of peak area and retention time was obtained at different concentration levels for over 125 injections without any instrument servicing. The main benefits of the nanoflow liquid chromatography approach are the high sensitivity gain and the outstanding reduction in matrix effects thanks to the high sample dilution factors that can be implemented, along with the substantial reduction in solvent usage. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Preparative Isolation and Purification of Flavone C-Glycosides from the Leaves of Ficus microcarpa L. f by Medium-Pressure Liquid Chromatography, High-Speed Countercurrent Chromatography, and Preparative Liquid Chromatography.

    Science.gov (United States)

    Wang, Xiaohong; Liang, Yong; Zhu, Licai; Xie, Huichun; Li, Hang; He, Junting; Pan, Man; Zhang, Tianyou; Ito, Yoichiro

    2010-01-01

    Combined with medium-pressure liquid chromatography (MPLC) and preparative high-performance liquid chromatography (perp-HPLC), high-speed countercurrent chromatography (HSCCC) was applied for separation and purification of flavone C-glycosides from the crude extract of leaves of Ficus microcarpae L. f. HSCCC separation was performed on a two-phase solvent system composed of methyl tert- butyl ether - ethyl acetate - 1-butanol - acetonitrile - 0.1% aqueous trifluoroacetic acid at a volume ratio of 1:3:1:1:5. Partially resolved peak fractions from HSCCC separation were further purified by preparative HPLC. Four well-separated compounds were obtained and their purities were determined by HPLC. The purities of these peaks were 97.28%, 97.20%, 92.23%, and 98.40%.. These peaks were characterized by ESI-MS(n). According to the reference, they were identified as orientin (peak I), isovitexin-3″-O-glucopyranoside (peak II), isovitexin (peak III), and vitexin (peak IV), yielded 1.2 mg, 4.5 mg, 3.3 mg, and 1.8 mg, respectively.

  12. High-performance liquid chromatography separation of unsaturated organic compounds by a monolithic silica column embedded with silver nanoparticles.

    Science.gov (United States)

    Zhu, Yang; Morisato, Kei; Hasegawa, George; Moitra, Nirmalya; Kiyomura, Tsutomu; Kurata, Hiroki; Kanamori, Kazuyoshi; Nakanishi, Kazuki

    2015-08-01

    The optimization of a porous structure to ensure good separation performances is always a significant issue in high-performance liquid chromatography column design. Recently we reported the homogeneous embedment of Ag nanoparticles in periodic mesoporous silica monolith and the application of such Ag nanoparticles embedded silica monolith for the high-performance liquid chromatography separation of polyaromatic hydrocarbons. However, the separation performance remains to be improved and the retention mechanism as compared with the Ag ion high-performance liquid chromatography technique still needs to be clarified. In this research, Ag nanoparticles were introduced into a macro/mesoporous silica monolith with optimized pore parameters for high-performance liquid chromatography separations. Baseline separation of benzene, naphthalene, anthracene, and pyrene was achieved with the theoretical plate number for analyte naphthalene as 36,000 m(-1). Its separation function was further extended to cis/trans isomers of aromatic compounds where cis/trans stilbenes were chosen as a benchmark. Good separation of cis/trans-stilbene with separation factor as 7 and theoretical plate number as 76,000 m(-1) for cis-stilbene was obtained. The trans isomer, however, is retained more strongly, which contradicts the long- established retention rule of Ag ion chromatography. Such behavior of Ag nanoparticles embedded in a silica column can be attributed to the differences in the molecular geometric configuration of cis/trans stilbenes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. ANALISIS RESIDU KLORPIRIFOS DALAM SAYUR-SAYURAN DENGAN TEKNIK HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC

    Directory of Open Access Journals (Sweden)

    Aman Sentosa Panggabean

    2016-06-01

    Full Text Available The research about analysis of chlorpyrifos residue in vegetables by using High Performance Liquid Chromatography (HPLC technique has been done. To obtain the optimal measurement results, the measurement performed several important parameters in the chromatographic system was composition of mobile phase, volume injection sample, flow rate and pH eluent. Optimum measurement conditions obtained was mobile phase composition (water : methanol with 70 : 30, volume injection sample are 5 mL, flow rate are 0.5mL/menit and pH eluent are 7. The analytical performance that obtained is good showed with the reproducibility value as percentage coefficient variance (% CV was 0.0664%, limit of detection (LOD was 0.44 ppm, with a recovery percentage of > 95%. The results obtained showed the HPLC technique can be used for the routine analysis in the determination of chlorpyrifos for the vegetable samples. Keywords: Chlorpyrifos, Vegetables, HPLC.

  14. Determination of prostaglandin analogs in cosmetic products by high performance liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Wittenberg, James B; Zhou, Wanlong; Wang, Perry G; Krynitsky, Alexander J

    2014-09-12

    A method was developed and validated for the determination of 16 prostaglandin analogs in cosmetic products. The QuEChERS (Quick, Easy, Cheap, Efficient, Rugged, Safe) liquid-liquid extraction method, typically used for pesticide residue analysis, was utilized as the sample preparation technique. The prostaglandin analogs were chromatographically separated and quantified using high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). Thirty-one cosmetic products were surveyed, and 13 products were determined to contain a prostaglandin analog with amounts ranging from 27.4 to 297μg/g. The calculated concentrations for the cosmetic products were in a similar range when compared to the concentrations of three different prostaglandin analog-containing prescription products. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Preparation and evaluation of pillararene bonded silica gel stationary phases for high performance liquid chromatography.

    Science.gov (United States)

    Zhao, Wenjie; Chu, Jianxiang; Xie, Fuwei; Duan, Qunpeng; He, Lijun; Zhang, Shusheng

    2017-02-17

    Pillararene bonded stationary phases for high performance liquid chromatography were prepared using 3-aminopropyltriethoxysilane as coupling reagent. The structure of the new materials was characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. The chromatographic performance and retention mechanism of the new stationary phases were evaluated in reversed-phase mode compared with C18 using different solute probes including Tanaka test solutes, polycyclic aromatic hydrocarbons, phenols and aromatic positional isomers. The new stationary phases could provide various interactions for different solutes, such as hydrophobic, hydrogen bonding, π-π and inclusion interactions. The synergistic effects resulting from aromatic rings, oxygen atoms, alkyl linkers and cavities in the new host molecules improved the separation selectivity by multiple retention mechanisms. Such hybrid stationary phases can provide more versatility and have great potential for the analysis of complex samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Core-Shell Columns in High-Performance Liquid Chromatography: Food Analysis Applications

    Directory of Open Access Journals (Sweden)

    Raffaella Preti

    2016-01-01

    Full Text Available The increased separation efficiency provided by the new technology of column packed with core-shell particles in high-performance liquid chromatography (HPLC has resulted in their widespread diffusion in several analytical fields: from pharmaceutical, biological, environmental, and toxicological. The present paper presents their most recent applications in food analysis. Their use has proved to be particularly advantageous for the determination of compounds at trace levels or when a large amount of samples must be analyzed fast using reliable and solvent-saving apparatus. The literature hereby described shows how the outstanding performances provided by core-shell particles column on a traditional HPLC instruments are comparable to those obtained with a costly UHPLC instrumentation, making this novel column a promising key tool in food analysis.

  17. HIGH PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR DETERMINATION OF NIFEDIPINE IN HUMAN PLASMA

    Directory of Open Access Journals (Sweden)

    MOHAMMAD ABDOLLAHI

    1999-10-01

    Full Text Available A relatively simple normal phase high performance liquid chromatography (HPLC method was modified for determination of nifedipine in human plasma. The method is based on ultraviolet detection at 235 nm and acidic plasma extraction by a mixture of dichioromethane (30% and n-hexane (70% using nimodipine as an internal standard. The system was stabilized with the use of n-hexane (80%, chloroform (17% and methanol (3% as mobile phase. The assay was linear up to at least 120 ng/ml of nifedipine in plasma. The limit of reliable determination was at least 3 ng/ml plasma. The reproducibility of the method was satisfactory. The procedure can be used effectively to quantitate nifedipine in the human plasma.

  18. [Determination of polysorbates in foods by solid-phase extraction and high-performance liquid chromatography].

    Science.gov (United States)

    Nomura, Chie; Kitagawa, Mikiya; Yoshida, Masaharu; Tanaka, Yukio

    2007-06-01

    A simple and rapid method using refractive index high-performance liquid chromatography (RI-HPLC) was developed for the determination of polysorbates (PS) in processed foods. PS were extracted with ethyl acetate containing 5% methanol. The extract was cleaned up on a multimode cartridge (300 mg) and an Alumina-N cartridge (500 mg) to remove fats and food color. HPLC separation was performed on a C18 column (4.6 i.d. x 150 mm) with methanol as the mobile phase. The recoveries of PS80 from nine kinds of foods fortified at the levels 1-5 g/kg were 80-99%. The limit of quantitation for PS80 in foods was 0.10 g/kg. The proposed method was applied to Worcestershire sauce that was PS-positive by TLC, and PS was confirmed to be present as PS80 at the concentration of 0.13 g/kg.

  19. Characterization of nine polyphenols in fruits of Malus pumila Mill by high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Lu Bai

    2016-04-01

    Full Text Available Polyphenols are important bioactive substances in apple. To explore the profiles of the nine representative polyphenols in this fruit, a high-performance liquid chromatography method has been established and validated. The validated method was successfully applied for the simultaneous characterization and quantification of these nine apple polyphenols in 11 apple extracts, which were obtained from six cultivars from Shaanxi Province, China. The results showed that only abscission of the Fuji apple sample was rich in the nine apple polyphenols, and the polyphenol contents of other samples varied. Although all the samples were collected in the same region, the contents of nine polyphenols were different. The proposed method could serve as a prerequisite for quality control of Malus products.

  20. Characterization of nine polyphenols in fruits of Malus pumila Mill by high-performance liquid chromatography.

    Science.gov (United States)

    Bai, Lu; Guo, Sen; Liu, Qingchao; Cui, Xueqin; Zhang, Xinxin; Zhang, Li; Yang, Xinwen; Hou, Manwei; Ho, Chi-Tang; Bai, Naisheng

    2016-04-01

    Polyphenols are important bioactive substances in apple. To explore the profiles of the nine representative polyphenols in this fruit, a high-performance liquid chromatography method has been established and validated. The validated method was successfully applied for the simultaneous characterization and quantification of these nine apple polyphenols in 11 apple extracts, which were obtained from six cultivars from Shaanxi Province, China. The results showed that only abscission of the Fuji apple sample was rich in the nine apple polyphenols, and the polyphenol contents of other samples varied. Although all the samples were collected in the same region, the contents of nine polyphenols were different. The proposed method could serve as a prerequisite for quality control of Malus products. Copyright © 2015. Published by Elsevier B.V.

  1. Use of high-performance liquid chromatography-diode array detection in forensic toxicology.

    Science.gov (United States)

    Koves, E M

    1995-02-10

    A comprehensive approach to the analysis for many drugs in postmortem blood and biological fluids using high-performance liquid chromatography and diode array detection has been developed. To reduce the likelihood of co-eluting interference components of postmortem blood or other drugs, selective back-extraction was also used to screen and quantitate drugs in blood and biofluids. An isocratic mobile phase (acetonitrile, phosphoric acid and triethylamine buffer, pH 3.4) was developed and found stable, reliable and convenient for general drug screening and quantitation. A library of drug spectra in the ultraviolet wavelength range (210-367 nm) was established for 272 drugs on two reversed-phase columns: Supelcosil (biphenyl) and LiChrospher RP-8. The application of several methods to whole blood, the analysis of complex cases and the use of multicomponent analysis for qualitative and quantitative analysis is discussed.

  2. SIMULTANEOUS DETERMINATION OF PARACETAMOL AND IBUPROFENE MIXTURES BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    Sophi Damayanti

    2010-06-01

    Full Text Available Analytical method for the determination of paracetamol and ibuprofene mixtures has been developed by High Performance Liquid Chromatography using C-18 column and acetinitrile - phosphate buffer pH = 4.5 (75:25 containing 0.075% sodium hexanesulfunate as a mobile phase. The detector was set at 215 nm. Using such conditions, retention time for paracetamol and ibuprofen was 4.89 and 7.11 min, respectively. The recovery for paracetamol and ibuprofen was found to be 101.07± 0.73% and 102.02 ± 1.58%, respectively. The detector limits of the method was 1.30 and 1.60 μg/mL with the relative standard deviation (RSD 0.74 and 1.52% for paracetamol and ibuprofen, respectively.   Keywords: paracetamol, ibuprofen, multi-component, validation, HPLC.

  3. High-performance liquid chromatography for determination of α-tocopherol in vegetables

    Directory of Open Access Journals (Sweden)

    Marcin Horbowicz

    2013-12-01

    Full Text Available A simple method for the determination of α-tocopherol in vegetables is described. The procedure consists of the following steps: saponification, extraction, silica-column clean-up, and high-performance liquid chromatography. Elution time for D, L-α-tocopherol was 9.0 min using a Zorbax Sil (250 x 4.6 mm column and an isocratic mobile phase of hexane-methanol (99.3 + 0.7, with a flow rate of 1 ml/min, and detection at 292 nm using a variable UV detector. The average recovery of α-tocopherol was 91.2%, and the minimum detectable amount was 0.1 mg/100 g of fresh vegetable tissue. This method is comparable to gas-chromatographic determination of α-tocopherol, but has fewer analytical steps and gives more reproducible results.

  4. Detection of cheese whey and caseinomacropeptide in fermented milk beverages using high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    E.H.P. Andrade

    2014-06-01

    Full Text Available Cheese whey level and caseinomacropeptide (CMP index of fermented milk beverages added with four levels of cheese whey (0, 10, 20, and 40% and stored at 8-10oC for 0, 7, 14 and 21 days were determined by high performance liquid chromatography-gel filtration (HPLC-GF. Additionally, the interference of the starter culture and the storage time on the detection of cheese whey and CMP were investigated. Refrigerated storage up to 21 days did not affect (P>0.05 cheese whey and CMP amounts in milk (0% of cheese whey and in fermented milk beverages added with 10 and 20% of cheese whey (P>0.05. However, cheese whey and CMP amounts were higher than expected (P<0.05 in fermented milk beverages added with 40% of cheese whey and stored for 21 days.

  5. Rapid analysis of starch, amylose and amylopectin by high-performance size-exclusion chromatography.

    Science.gov (United States)

    Kobayashi, S; Schwartz, S J; Lineback, D R

    1985-02-01

    Starch components, amylose and amylopectin, were analyzed by high-performance size-exclusion chromatography. These two-components were separated using a two-column system (E-Linear and E-1000) and dimethyl sulphoxide as the mobile phase. The void volume (V0 = 2.22 ml) was measured using tobacco mosaic virus. Column calibration was accomplished with dextrans of known average molecular weight (Mw range = 10,100-2,000,000). The elution volume of amylopectin (Ve = 2.5 ml) indicated that this starch component was fractionated on the column system despite its very large molecular size. Standard curves were prepared from various mixtures of purified corn and wheat amylose and amylopectin. From the linear relationships obtained, the percentages of both components in corn and wheat starches were determined. The method developed proved useful to monitor the purity of amylose and amylopectin preparations, and to estimate rapidly the amylose:amylopectin ratio of starch samples.

  6. Analysis of lipophilic pigments from a phototrophic microbial mat community by high performance liquid chromatography

    Science.gov (United States)

    Palmisano, A. C.; Cronin, S. E.; Des Marais, D. J.

    1988-01-01

    As assay for lipophilic pigments in phototrophic microbial mat communities using reverse phase-high performance liquid chromatography was developed which allows the separation of 15 carotenoids and chloropigments in a single 30 min program. Lipophilic pigments in a laminated mat from a commercial salina near Laguna Guerrero Negro, Baja California Sur, Mexico reflected their source organisms. Myxoxanthophyll, echinenone, canthaxanthin, and zeaxanthin were derived from cyanobacteria; chlorophyll c, and fucoxanthin from diatoms; chlorophyll a from cyanobacteria and diatoms; bacteriochlorophylls a and c, bacteriophaeophytin a, and gamma-carotene from Chloroflexus spp.; and beta-carotene from a variety of phototrophs. Sensitivity of detection was 0.6-6.1 ng for carotenoids and 1.7-12 ng for most chloropigments. This assay represents a significant improvement over previous analyses of lipophilic pigments in microbial mats and promises to have a wider application to other types of phototrophic communities.

  7. High performance thin layer chromatography fingerprint analysis of guava (Psidium guajava) leaves

    Science.gov (United States)

    Astuti, M.; Darusman, L. K.; Rafi, M.

    2017-05-01

    High-performance thin layer chromatography (HPTLC) fingerprint analysis is commonly used for quality control of medicinal plants in term of identification and authentication. In this study, we have been developed HPTLC fingerprint analysis for identification of guava (Psidium guajava) leaves raw material. A mixture of chloroform, acetone, and formic acid in the ratio 10:2:1 was used as the optimum mobile phase in HPTLC silica plate and with 13 bands were detected. As reference marker we chose gallic acid (Rf = 0.21) and catechin (Rf = 0.11). The two compound were detected as pale black bands at 366 nm after derivatization with sulfuric acid 10% v/v (in methanol) reagent. Validation of the method was met within validation criteria, so the developed method could be used for quality control of guava leaves.

  8. Saffron authentication based on liquid chromatography high resolution tandem mass spectrometry and multivariate data analysis.

    Science.gov (United States)

    Rubert, Josep; Lacina, Ondrej; Zachariasova, Milena; Hajslova, Jana

    2016-08-01

    Saffron is one of the oldest and most expensive spices, which is often target of fraudulent activities. In this research, a new strategy of saffron authentication based on metabolic fingerprinting was developed. In the first phase, a solid liquid extraction procedure was optimized, the main aim was to isolate as maximal representation of small molecules contained in saffron as possible. In the second step, a detection method based on liquid chromatography coupled with high-resolution mass spectrometry was developed. Initially, principal component analysis (PCA) revealed clear differences between saffron cultivated and packaged in Spain, protected designation of origin (PDO), and saffron packaged in Spain of unknown origin, labeled Spanish saffron. Afterwards, orthogonal partial least square discriminant analysis (OPLS-DA) was favorably used to discriminate between Spanish saffron. The tentative identification of markers showed glycerophospholipids and their oxidized lipids were significant markers according to their origin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Separative determination of ascorbic acid and erythorbic acid by high-performance liquid chromatography.

    Science.gov (United States)

    Arakawa, N; Otsuka, M; Kurata, T; Inagaki, C

    1981-01-01

    High-performance liquid chromatography (HPLC) was applied to the determination of ascorbic acid (AsA) and erythorbic acid (ErA). The apparatus was a Shimadzu model LC-2P Liquid Chromatograph equipped with a UV detector set at 254 nm. The separation was achieved on a LiChrosorb-NH2 column which was pre-treated with 0.1 M ammonium monophosphate solution using a mixture of acetonitrile, acetic acid and water (87:2:11, v/v) as an eluant. The HPLC method has the following advantages: AsA and ErA are quantitated after being distinctly separated, analysis time per one sample is short, and AsA or ErA levels as low as 1.0 X 10(-2) microgram are detectable. Recovery experiments with dehydro-AsA and dehydro-ErA, involving reduction with H2S, give satisfactory results.

  10. [Determination of aspirin and free salicylic acid in lysinipirine injection by high performance liquid chromatography].

    Science.gov (United States)

    Dong, Yu; Zhao, Yuan-zheng; Zhang, Yi-na

    2002-05-01

    The contents of aspirin and free salicylic acid in lysinipirine injection were determined by high performance liquid chromatography (HPLC). A Hypersil BDS C18 column was used with the mobile phase of methanol-water-acetic acid (35:65:3, volume ratio) and the detection wavelength of 280 nm. The average recoveries of aspirin and salicylic acid added were 99.27% (RSD = 0.8%) and 99.61%(RSD = 1.3%), respectively. The calibration curves had good linearity in the range of 0.028 g/L -0.141 mg/L and 0.77 mg/L -3.85 mg/L, and the correlation coefficients were 0.9999 and 0.9998 for aspirin and salicylic acid respectively.

  11. Determination of primary amino acids in wines by high performance liquid magneto-chromatography.

    Science.gov (United States)

    Barrado, E; Rodriguez, J A; Castrillejo, Y

    2009-05-15

    Eight amino acids (ethanolamine, glycine, alanine, beta-aminobutyric acid, leucine, methionine, histidine and asparagine) were identified and quantified in Spanish wines by high performance liquid magneto-chromatography (HPLMC) with UV-V spectrophotometry. For this method, the amino acids are first complexed with mono(1,10-phenanthroline)-Cu(II) to confer them paramagnetic properties, and then separated by application of a low magnetic field intensity (5.5 mT) to the stationary phase contained in the chromatographic column. Principal components analysis of the results obtained grouped together the wine samples according to their denomination of origin: "Ribera del Duero", "Rueda" or "Rioja" (Spain). Through cluster analysis, a series of correlations was also observed among certain amino acids, and between these groupings and the type of wine. These clusters were found to reflect the role played by the amino acids as primary or secondary nutrients for the bacteria involved in alcoholic and malolactic fermentation.

  12. High performance liquid chromatography method for the determination of cinnamyl alcohol dehydrogenase activity in soybean roots.

    Science.gov (United States)

    dos Santos, W D; Ferrarese, Maria de Lourdes Lucio; Ferrarese-Filho, O

    2006-01-01

    This study proposes a simple, quick and reliable method for determining the cinnamyl alcohol dehydrogenase (CAD; EC 1.1.1.195) activity in soybean (Glycine max L. Merr.) roots using reversed-phase high performance liquid chromatography (RP-HPLC). The method includes a single extraction of the tissue and conduction of the enzymatic reaction at 30 degrees C with cinnamaldehydes (coniferyl or sinapyl), substrates of CAD. Disappearance of the substrates in the reaction mixture is monitored at 340 nm (for coniferaldehyde) or 345 nm (for sinapaldehyde) by isocratic elution with methanol/acetic acid through a GLC-ODS (M) column. This HPLC technique furnishes a rapid and reliable measure of cinnamaldehyde substrates, and may be used as an alternative tool to analyze CAD activity in enzyme preparation without previous purification.

  13. High-throughput determination of cortisol, cortisone, and melatonin in oral fluid by on-line turbulent flow liquid chromatography interfaced with liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Fustinoni, Silvia; Polledri, Elisa; Mercadante, Rosa

    2013-07-15

    Cortisol, cortisone, and melatonin (CORTol, CORTone, and MELA, respectively) are hormones related to stress and sleep disorders. Their detection is relevant to epidemiological studies aimed at investigating the effects of circadian cycle disruption. The aim of this study was to develop and evaluate a high-throughput assay for the detection of CORTol, CORTone, and MELA concentrations in non-invasively collected oral fluid samples. A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method to measure levels of CORTol, CORTone, and MELA in oral fluid samples in the presence of deuterated analogs was optimized and validated. A 50 μL aliquot of oral fluid sample, obtained by centrifugation of a chewed swab, was purified using on-line turbulent flow liquid chromatography. Analytes were then separated using C18 reversed-phase chromatography, subjected to positive ionization using an electrospray source, then quantitated using a triple quadrupole mass detector in the selected reaction monitoring mode. Limits of quantification and linear dynamic ranges were found to be 0.55 nmol/L, 5.5 nmol/L, and 0.004 nmol/L, and up to 28 nmol/L, 277 nmol/L, and 0.43 nmol/L for CORTol, CORTone, and MELA, respectively. Inter- and intra-run precisions as relative standard deviation values were <5%, and accuracies were within 95-106% of theoretical concentrations. An evaluation of matrix effects showed that the use of deuterated analogs controlled sources of bias. Furthermore, the total analysis time per sample was 13 min, resulting in a throughput of approximately 100 samples/day. To our knowledge, this is the first automated, high-throughput assay for the simultaneous quantification of CORTol, CORTone, and MELA in oral fluid specimens. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Application of high-temperature gas chromatography to the analysis of used frying fats

    Directory of Open Access Journals (Sweden)

    Aguirre, M.

    2010-06-01

    Full Text Available The determination of polar compounds is the most commonly applied technique in the analysis of used frying fats and oils. High-temperature gas chromatography allows for a quantitative determination of oxidized monomeric FAME and dimeric FAME thus giving extra information on oil degradation starting from the fraction of polar compounds. Polar compounds are transesterified and methyl esters are separated in a VF-5ht Ultimetal column (150 °C -held for 5 min- rising at 5 °C min-1 to 370 °C and held for 5 min using methyl tricosanoate as internal standard. Results are compared with those obtained by more complex alternative methodology using high-performance size-exclusion chromatography.

    La determinación de compuestos polares es el método analítico más utilizado en el análisis de los aceites y grasas de fritura. En este estudio se aprovechan las posibilidades actuales de la cromatografía de gases a elevada temperatura que permite cuantificar los dos grupos mayoritarios de ácidos grasos polares como ésteres metílicos: los monómeros oxidados y los dímeros. Con tal fin, la fracción de compuestos polares se tranesterifica y los ésteres metílicos obtenidos se separan en una columna de VF-5ht Ultimetal, usando tricosanoato de metilo como estándar interno, en las siguientes condiciones: 150 °C durante 5 minutos, 5 °C/min hasta 370 °C y 5 minutos a 370 °C. Los resultados se comparan con los obtenidos mediante técnica alternativa más compleja basada en la cromatografía de exclusión por tamaño molecular.

  15. Simultaneous quantification of various retinoids by high performance liquid chromatography: its relevance to alcohol research.

    Science.gov (United States)

    Yokoyama, H; Matsumoto, M; Shiraishi, H; Ishii, H

    2000-04-01

    We established a high performance liquid chromatography system that allowed simultaneous quantification of various retinoids. We applied the retinoids to a high performance liquid chromatography system with a silica gel absorption column. Samples were separated by the system with a binary multistep gradient with two kinds of solvent that contained n-Hexan, 2-propanol, and glacial acetic acid in different ratios. Each retinoid was detected at a wavelength of 350 nm. This condition allowed separation of 13-cis-retinoic acid, 9-cis-retinoic acid, all-trans-retinoic acid, 13-cis-retinol, all-trans-retinol, all-trans-4-oxo-retinoic acid, and 13-cis-4-oxo-retinoic acid as distinct single peaks. Each retinoid was also analyzed separately and its retention time determined. To ascertain the reliability of this system for retinoid quantification, retinoids at various concentrations were applied to the system. We observed the linearities between the concentration and area under the curve of the peak for each retinoid by linear least-squares regression analysis up to 2.5 ng/ml for all retinoic acids and up to 5 ng/ml for all retinols. There was no significant scattering in tests of within-day reproducibility or day-to-day reproducibility. Using this system, we examined effects of light exposure on isomerization of retinoids. When retinoids were exposed to room light for 2 hr, the amounts of all but 13-cis-retinol changed significantly. In particular, the amounts of all-trans-retinoic acid and 9-cis-retinoic acid were reduced by 40% and 60%, respectively. The HPLC system established in this study should be useful for studying the oxidation pathway of retinol to retinoic acid. A light-shielded condition is required when particular retinoic acids are analyzed.

  16. Structural Characterisation of Acetogenins from Annona muricata by Supercritical Fluid Chromatography Coupled to High-Resolution Tandem Mass Spectrometry.

    Science.gov (United States)

    Laboureur, Laurent; Bonneau, Natacha; Champy, Pierre; Brunelle, Alain; Touboul, David

    2017-11-01

    Acetogenins are plant polyketides known to be cytotoxic and proposed as antitumor candidates. They are also suspected to be alimentary neurotoxins. Their occurrence as complex mixtures renders their dereplication and structural identification difficult using liquid chromatography coupled to tandem mass spectrometry and efforts are required to improve the methodology. To develop a supercritical fluid chromatography (SFC) high-resolution tandem mass spectrometry method, involving lithium post-column cationisation, for the structural characterisation of Annonaceous acetogenins in crude extracts. The seeds of Annona muricata L. were extracted with methanol. Supercritical fluid chromatography of the extract, using a 2-ethylpyridine stationary phase column, was monitored using a high-resolution quadrupole time-of-flight mass spectrometer. Lithium iodide was added post-column in the make-up solvent. For comparison, the same extract was analysed using high-pressure liquid chromatography coupled to the same mass spectrometer, with a column based on solid core particles. Sensitivity was similar for both HPLC and SFC approaches. Retention behaviour and fragmentation pathways of three different isomer groups are described. A previously unknown group of acetogenins was also evidenced for the first time. The use of SFC-MS/MS allows the reduction of the time of analysis, of environmental impact and an increase in the chromatographic resolution, compared to liquid chromatography. This new methodology enlightened a new group of acetogenins, isomers of montanacin-D. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  17. High Speed Counter Current Chromatography-A Support free LC Technique

    Directory of Open Access Journals (Sweden)

    Garima Jain

    2009-12-01

    Full Text Available

    As separation of components is the major requirement of an analytical chemist, there is always a need of a convenient
    high throughput technique with minimum sample loss, high efficiency, high resolution, ease of sample
    recovery without contamination. This leads to the development of High Speed Counter Current Chromatography
    (HSCCC in which stationary phase is liquid instead of solid that provides a lot of advantages over other chromatographic
    techniques. In addition, advanced centrifugal partition technology is used to hold the liquid stationary
    phase in column while the liquid mobile phase is pushed through it that provides high yield and purity. This review
    highlights the major applications of HSCCC that includes extraction of medicinal drugs from plants and
    purification and isolation of active material, plant analysis, separation of rare earth elements, preparative-scale
    separations of chiral compounds, analysis of inorganic compounds and elements and drug discovery and drug
    development. Separation of dipeptides and proteins, flavonoids, alkaloids, DNP amino acids, indole auxins etc.
    proves versatile and dynamic nature of the technique.

  18. Mutation analysis in {beta}{sub 2-}adrenergic receptor gene by denaturing high performance liquid chromatography (DHPLC)

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.B.; Oh, C.H.; Kim, J.W.; Jang, W.C. [Dankook University, Cheonan (Korea)

    2002-06-01

    We analysed mutation of {beta}{sub 2-}adrenergic receptor gene that controls bronchial asthma by denaturing high performance liquid chromatography (DHPLC) according to ion-pair reversed-phase high performance liquid chromatography (IP-RP-HPLC). We extracted genomic DNA from 50 asthma patients, amplified DNA using PCR, and analysed PCR product by DHPLC. As a result, we obtained that mutation frequency was 15(30%) among 50 cases. Consequently DHPLC mutation detection was confirmed that the result of direct sequencing was coincide exactly. (author). 13 refs., 4 figs.

  19. Rapid analysis of the interactions between drugs and human serum albumin (HSA) using high-performance affinity chromatography (HPAC).

    Science.gov (United States)

    Kim, Hee Seung; Wainer, Irving W

    2008-07-01

    This study used a combination of zonal elution and frontal affinity chromatography on immobilized human serum albumin (HSA) high-performance affinity chromatography (HPAC) column to examine the association constants of various compounds that have been studied by equilibrium dialysis or ultra filtration. A standard plot was generated from retention factors of reference compounds using zonal elution chromatography against association constants of reference compounds using frontal affinity chromatography. The linear relationship was established (r2=0.9993) between retention factors and association constants of reference compounds. This standard plot was later used for rapid determination of association constants of various drugs which show low to medium binding affinity to HSA. Association constants of those drugs from this study were compared to that of more generally used methods (i.e., equilibrium dialysis or ultra filtration) from literature and resulted in a relatively high correlation (r2=0.945) value. This combination of zonal elution and frontal affinity chromatography method for determining association constants showed several advantages against traditional methods. Depending on drugs of interest, an association constant of drug to HSA can be measured as fast as 1.5 min. Other notable advantages include an ease of automation and its ability to distinguish association constants of chiral compounds at the same time. The same approach could be used for studying interaction of other drugs and proteins and should further improve overall drug screening process.

  20. Determination of aflatoxins in medicinal plants by high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Siddique, Nadeem A; Mujeeb, Mohd; Ahmad, Sayeed; Panda, Bibhu P; Makhmoor, Mohd

    2013-01-01

    The intention of the proposed work is to study the presence of the aflatoxins B1, B2, G1 and G2 in medicinal plants, namely Mucuna pruriens, Delphinium denudatum and Portulaca oleraceae. The aflatoxins were extracted, purified by immunoaffinity column chromatography and analysed by high-performance liquid chromatography-tandem quadrupole mass spectrometry with electrospray ionisation (HPLC-MS/MS). Fungal count was carried out in PDA media. A good linear relationship was found for AFB1, AFB2, AFG1 and AFG2 at 1-10 ppb (r>0.9995). The analyte accuracy under three different spiking levels was 86.7-108.1 %, with low per cent relative standard deviations in each case. The aflatoxins can be separated within 5 to7 min using an Agilent XDB C18-column. We found that AFB1 and AFB2 were in trace amounts below the detection limit in M. pruriens whilst they were not detected in D. denudatum. P. oleraceae was found to be contaminated with AFB1 and AFB2. AFG1 and AFG2 were not detected in M. pruriens, P. oleraceae and were below the detection limit in D. denudatum. This was consistent with very low numbers of fungal colonies observed after 6 hr of incubation. The analytical method developed is simple, precise, accurate, economical and can be effectively used to determine the aflatoxins in medicinal plants and therefore to control the quality of products. The aflatoxin levels in the plant extracts examined were related to the minimal fungal load in the medicinal plants examined.

  1. Biointeraction analysis by high-performance affinity chromatography: Kinetic studies of immobilized antibodies.

    Science.gov (United States)

    Nelson, Mary Anne; Moser, Annette; Hage, David S

    2010-01-15

    A system based on high-performance affinity chromatography was developed for characterizing the binding, elution and regeneration kinetics of immobilized antibodies and immunoaffinity supports. This information was provided by using a combination of frontal analysis, split-peak analysis and peak decay analysis to determine the rate constants for antibody-antigen interactions under typical sample application and elution conditions. This technique was tested using immunoaffinity supports that contained monoclonal antibodies for 2,4-dichlorophenoxyacetic acid (2,4-D). Association equilibrium constants measured by frontal analysis for 2,4-D and related compounds with the immobilized antibodies were 1.7-12x10(6)M(-1) at pH 7.0 and 25 degrees C. Split-peak analysis gave association rate constants of 1.4-12x10(5)M(-1)s(-1) and calculated dissociation rate constants of 0.01-0.4s(-1) under the application conditions. Elution at pH 2.5 for the analytes from the antibodies was examined by peak decay analysis and gave dissociation rate constants of 0.056-0.17s(-1). A comparison of frontal analysis results after various periods of column regeneration allowed the rate of antibody regeneration to be examined, with the results giving a first-order regeneration rate constant of 2.4x10(-4)s(-1). This combined approach and the information it provides should be useful in the design and optimization of immunoaffinity chromatography and other analytical methods that employ immobilized antibodies. The methods described are not limited to the particular analytes and antibodies employed in this study but should be useful in characterizing other targets, ligands and supports. 2009 Elsevier B.V. All rights reserved.

  2. Geographical tracing of Xihu Longjing tea using high performance liquid chromatography.

    Science.gov (United States)

    Wang, Liyuan; Wei, Kang; Cheng, Hao; He, Wei; Li, Xinghui; Gong, Wuyun

    2014-03-01

    Xihu Longjing tea (XHLJ) is one of the most famous green tea in China. Due to its high price, some inauthentic XHLJ from other tea producing areas appear on the market and hurt the interests of customers and producers. High-performance liquid chromatography (HPLC) combined with the principal component analysis (PCA) and linear discriminant analysis (LDA) methods were applied to the geographical tracing of XHLJ from two other types of Longjing teas and a non-Longjing flatten-shaped tea (non-LJ). The chromatograms of the tea samples from four different regions were highly similar. It was difficult to classify 4 types of teas directly by PCA. However, high total accuracy rates of 94.8% and 87.6% for the training and test set were achieved for distinguishing XHLJ from the other three types of tea by stepwise discriminant analysis. The identification accuracy of XHLJ from non-LJ was the highest, suggesting geographical distance might play an important role in this process. In summary, a combination of chromatographic chemical fingerprints with LDA provides a simple and rapid approach for the identification of XHLJ from other teas. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Recent advances in ultra-high performance liquid chromatography for the analysis of traditional chinese medicine

    Science.gov (United States)

    Traditional Chinese medicines (TCMs) have been widely used for the prevention and treatment of various diseases for thousands of years in China. Ultra Performance Liquid Chromatography (UHPLC) is a relatively new technique offering new possibilities in liquid chromatography. This paper reviews recen...

  4. Simultaneous detection of water-soluble vitamins using the High Performance Liquid Chromatography (HPLC - a review

    Directory of Open Access Journals (Sweden)

    Rosemond Godbless Dadzie

    2014-01-01

    Full Text Available The water-soluble vitamins (WSV: ascorbic acid (vitamin C, thiamine (B1, riboflavin (B2, niacin (B3, panthothenic acid (B5, pyridoxine, and pyridoxal (B6, folic acid (B9, biotin(B8 , and B12 are very essential in the diet of humankind. As a result of ever increasing pressures from both consumers and legal enforcers, to specify accurately nutritive compositions of WSV that are present in food materials, many researchers have attempted to fill this niche through the provision of highly sensitive and rapid high performance liquid chromatography (HPLC procedures. In view of the health benefits of WSV, a replete of HPLC methods have been developed for simultaneous determination of their contents in nature and fortified food samples, nutritional supplements, as well as blood plasmas. The rate of losses of these vitamins during food processing and analysis, in addition to their transient dynamics, presents complexities in developing a highly sensitive HPLC procedure for their simultaneous separations and assays. This review critically assesses the different HPLC procedures developed by researchers and available in the open literature for simultaneous determination of water-soluble vitamins (WSV in dried tropical fruits materials. The study revealed that not a single chromatographic run developed by researchers can simultaneously elute all the WSV at a time. However, the HPLC procedures that are capable of determining all the WSV were coupled with electrospray ionization mass spectroscopy (ESI-MS, thus making the set-up expensive.

  5. Determination of vinblastine in tumour tissue with liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Kosjek, Tina; Dolinšek, Tanja; Gramec, Darja; Heath, Ester; Strojan, Primož; Serša, Gregor; Čemažar, Maja

    2013-11-15

    There are virtually no analytical methods that describe determination of vinblastine and other vinca alkaloids in tumour tissue, albeit quantitative data on tumour drug amount is essential for maximal benefit of a particular anticancer treatment. The analytical method presented herein uses state-of-the-art sample preparation, separation and detection techniques to allow sensitive and selective determination of vinblastine in tumour tissue. After cryogenic grinding and sonication, tumour suspensions were extracted by Oasis MAX solid phase extraction and analysed for vinblastine with ultra-high performance liquid chromatography coupled to positive electrospray ionisation-high resolution mass spectrometric detection. The developed analytical method quantifies vinblastine down to 23 ng/g tumour tissue and shows satisfactory linearity (r(2)>0.99), precision (1.1-8.2%), accuracy (98%) and high selectivity with almost complete absence of matrix effects. The proposed method was found suitable to follow vinblastine levels in mice tumours and could be used to support preclinical pharmacologic studies. © 2013 Elsevier B.V. All rights reserved.

  6. Rapid isolation and purification of phorbol esters from Jatropha curcas by high-speed countercurrent chromatography.

    Science.gov (United States)

    Hua, Wan; Hu, Huiling; Chen, Fang; Tang, Lin; Peng, Tong; Wang, Zhanguo

    2015-03-18

    In this work, a high-speed countercurrent chromatography (HSCCC) method was established for the preparation of phorbol esters (PEs) from Jatropha curcas. n-Hexane-ethyl acetate-methanol-water (1.5:1.5:1.2:0.5, v/v) was selected as the optimum two-phase solvent system to separate and purify jatropha factor C1 (JC1) with a purity of 85.2%, as determined by HPLC, and to obtain a mixture containing four or five PEs. Subsequently, continuous semipreparative HPLC was applied to further purify JC1 (99.8% as determined by HPLC). In addition, UPLC-PDA and UPLC-MS were established and successfully used to evaluate the isolated JC1 and PE-rich crude extract. The purity of JC1 was only 87.8% by UPLC-UV. A peak (a compound highly similar to JC1) was indentified as the isomer of JC1 by comparing the characteristic UV absorption and MS spectra. Meanwhile, this strategy was also applied to analyze the PE-rich crude extract from J. curcas. It is interesting that there may be more than 15 PEs according to the same quasi-molecular ion peaks, highly similar sequence-specific fragment ions, and similar UV absorption spectrum.

  7. Gas chromatography flow rates for determining deuterium/hydrogen ratios of natural gas by gas chromatography/high-temperature conversion/isotope ratio mass spectrometry.

    Science.gov (United States)

    Jia, Wanglu; Peng, Ping'an; Liu, Jinzhong

    2008-08-01

    The effects of the gas chromatography flow rate on the determination of the deuterium/hydrogen (D/H) ratios of natural gas utilising gas chromatography/high-temperature conversion/isotope ratio mass spectrometry (GC/TC/IRMS) have been evaluated. In general, the measured deltaD values of methane, ethane and propane decrease with increase in column flow rate. When the column flow rate is 1 mL/min or higher, which is commonly used for the determination of D/H ratios of natural gas, the organic H in gas compounds may not be completely converted into hydrogen gas. Based on the results of experiments conducted on a GC column with an i.d. of 0.32 mm, a GC flow rate of 0.6 mL/min is proposed for determining the D/H ratios of natural gas by GC/TC/IRMS. Although this value may be dependent on the instrument conditions used in this work, we believe that correct deltaD values of organic compounds with a few carbon atoms are obtained only when relatively low GC flow rates are used for D/H analysis by GC/TC/IRMS. Moreover, as the presence of trace water could significantly affect the determination of D/H ratios, a newly designed inlet liner was used to remove trace water contained in some gas samples. Copyright (c) 2008 John Wiley & Sons, Ltd.

  8. Analyses of Indole Compounds in Sugar Cane (Saccharum officinarum L. Juice by High Performance Liquid Chromatography and Liquid Chromatography-Mass Spectrometry after Solid-Phase Extraction

    Directory of Open Access Journals (Sweden)

    Jean Wan Hong Yong

    2017-03-01

    Full Text Available Simultaneous quantitative analysis of 10 indole compounds, including indole-3-acetic acid (IAA, one of the most important naturally occurring auxins and some of its metabolites, by high performance liquid chromatography (HPLC and liquid chromatography-mass spectrometry (LC-MS after solid-phase extraction (SPE was reported for the first time. The analysis was carried out using a reverse phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid modified by methanol. Furthermore, a novel SPE procedure was developed for the pre-concentration and purification of indole compounds using C18 SPE cartridges. The combination of SPE, HPLC, and LC-MS was applied to screen for the indole compounds present in sugar cane (Saccharum officinarum L. juice, a refreshing beverage with various health benefits. Finally, four indole compounds were successfully detected and quantified in sugar cane juice by HPLC, which were further unequivocally confirmed by LC-MS/MS experiments operating in the multiple reaction monitoring (MRM mode.

  9. Determination of Alternaria mycotoxins in wine and juice using ionic liquid modified countercurrent chromatography as a pretreatment method followed by high-performance liquid chromatography.

    Science.gov (United States)

    Fan, Chen; Cao, Xueli; Liu, Man; Wang, Wei

    2016-03-04

    Alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA) are some of the main Alternaria mycotoxins that can be found as contaminants in food materials. The objective of this study was to develop a pretreatment method with countercurrent chromatography (CCC) for enrichment and cleanup of trace Alternaria mycotoxins in food samples prior to high-performance liquid chromatography (HPLC) analysis. An Analytical CCC instrument with a column volume 22.5mL was used, and a two-phase solvent system composed of ethyl acetate and water modified with 6% [HOOMIM][Cl] in mass to volume ratio was selected. Under the optimized CCC operation conditions, trace amounts of AOH, AME, and TeA in large volume of liquid sample were efficiently extracted and enriched in the stationary phase, and then eluted out just by reversing the stationary phase as mobile phase in the opposite flowing direction tail-to-head. The enrichment and elution strategies are unique and can be fulfilled online with high enrichment factors (87-114) and high recoveries (81.14-110.94%). The method has been successively applied to the determination of Alternaria mycotoxins in real apple juice and wine samples with the limits of detection (LOD) in the range of 0.03-0.14μgL(-1). Totally 12 wine samples and 15 apple juice samples from the local market were analyzed. The detection rate of AOH and AME in both kinds of the samples were more than 50%, while TeA was found in relatively high level of 1.75-49.61μgL(-1) in some of the apple juice samples. The proposed method is simple, rapid, and sensitive and could also be used for the analysis and monitoring of Alternaria mycotoxin in other food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Improved method for the determination of the cortisol production rate using high-performance liquid chromatography and liquid scintillation counting

    NARCIS (Netherlands)

    van Ingen, H. E.; Endert, E.

    1988-01-01

    Two new methods for the determination of the cortisol production rate using reversed-phase high-performance liquid chromatography are described. One uses ultraviolet detection at 205 nm, the other on-line post-column derivatization with benzamidine, followed by fluorimetric detection. The specific

  11. Simultaneous Determination of Caffeine and Vitamin B6 in Energy Drinks by High-Performance Liquid Chromatography (HPLC)

    Science.gov (United States)

    Leacock, Rachel E.; Stankus, John J.; Davis, Julian M.

    2011-01-01

    A high-performance liquid chromatography experiment to determine the concentration of caffeine and vitamin B6 in sports energy drinks has been developed. This laboratory activity, which is appropriate for an upper-level instrumental analysis course, illustrates the standard addition method and simultaneous determination of two species. (Contains 1…

  12. Identification and quantification of cannabinoids in Cannabis sativa L. plants by high performance liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Aizpurua-Olaizola, Oier; Omar, Jone; Navarro, Patricia; Olivares, Maitane; Etxebarria, Nestor; Usobiaga, Aresatz

    2014-01-01

    High performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) has been successfully applied to cannabis plant extracts in order to identify cannabinoid compounds after their quantitative isolation by means of supercritical fluid extraction (SFE). MS conditions were optimized by means

  13. Determination of methyldibromoglutaronitrile in cosmetic products by high-performance liquid chromatography with electrochemical detection. Method validation

    DEFF Research Database (Denmark)

    Rastogi, Suresh Chandra; Zachariae, Claus; Johansen, Jeanne D

    2004-01-01

    An increased frequency of contact allergy to methyldibromoglutaronitrile (MDBGN), a commonly used preservative in cosmetics and other consumer products, has been reported in recent years. A high-performance liquid chromatography (HPLC) method for the determination of MDBGN in cosmetic products ha...

  14. Evaluation of gas chromatography – electron ionization – full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis

    NARCIS (Netherlands)

    Mol, Hans G.J.; Tienstra, Marc; Zomer, Paul

    2016-01-01

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS

  15. Three-mode factor analysis of data on retention in normal-phase high-performance liquid chromatography

    NARCIS (Netherlands)

    Ligny, C.L. de; Spanjer, M.C.; Houwelingen, J.C. van; Weesie, H.M.

    1984-01-01

    It is shown that the Snyder equation is not quite satisfactory for fitting retention data in normal-phase high-performance liquid chromatography (HPLC) on chemically bonded phases. This equation is a special case of the mathematical—statistical three-mode factor analysis model. This model, in its

  16. Determination of Polycyclic Aromatic Hydrocarbons in Automobile Exhaust by Means of High-Performance Liquid Chromatography with Fluorescence Detection

    DEFF Research Database (Denmark)

    Nielsen, Tom

    1979-01-01

    A chromatographic method has been developed and applied to the determination of polycyclic aromatic hydrocarbons (PAHs) in particulate matter in automobile exhaust, in petrols, and in crankcase oils. The PAHs were purified from other organic compounds by thin-layer chromatography, separated by high-performance...

  17. Constructing a LabVIEW-Controlled High-Performance Liquid Chromatography (HPLC) System: An Undergraduate Instrumental Methods Exercise

    Science.gov (United States)

    Smith, Eugene T.; Hill, Marc

    2011-01-01

    In this laboratory exercise, students develop a LabVIEW-controlled high-performance liquid chromatography system utilizing a data acquisition device, two pumps, a detector, and fraction collector. The programming experience involves a variety of methods for interface communication, including serial control, analog-to-digital conversion, and…

  18. Simultaneous determination of estrogens and progestogens in honey using high performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    This work describes the development and validation of a method for the simultaneous determination of 13 estrogens and progestogens in honey by high performance liquid chromatography-tandem mass spectrometry. The target compounds were preconcentrated by solid phase extraction. Pretreatment variables ...

  19. Device to generate high purity hydroxide solution in-line for ion chromatography.

    Science.gov (United States)

    Masunaga, Hiroto; Higo, Yuji; Ishii, Mizuo; Maruyama, Noboru; Yamazaki, Shigeo

    2016-05-06

    Herein, we report a new device that generates a high-purity hydroxide solution in line. The device's container has three compartments that are isolated from each other by two cation exchange (CE) membranes. In each end of the container, an electrode is installed. The three compartments are filled with ion exchange resins. A bipolar boundary is a composite boundary comprising anion- and cation-exchangers. This device has two bipolar boundaries, which are used to separate the location of hydroxide solution generation from the location where water is electrolyzed. Therefore, it can produce high-purity hydroxide solutions that are free from gases and anionic impurities. The hydroxide solution is generated on the basis of an electrokinetic phenomenon at the surfaces of ion-exchange resins and membranes in an electric field; NaOH concentration can be controlled at rates from 0.01 to 100mM per 1mL/min by adjusting the electrical current (0-200mA) applied to the device. As the generated solution is used as an eluent for a suppressed anion chromatography, the electrical conductivity of the effluent from the suppressor is as low as that of ultra-pure water. Thus, the noise of the base-line electrical conductivity is improved, and so the detection limit of anions on the sub-ng/mL order can be achieved. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Determination of meropenem levels in human serum by high-performance liquid chromatography with ultraviolet detection.

    Science.gov (United States)

    Roth, Thomas; Fiedler, Stella; Mihai, Sidonia; Parsch, Hans

    2017-05-01

    Meropenem is a β-lactam broad-spectrum antibiotic and belongs to the subgroup of carbapenems. It is primarily used in intensive care units for intravenous treatment of severe infections. To avoid bacterial resistance or toxic side effects, the determination of serum meropenem concentration is highly advisable. A simple and fast method for the quantitative determination of meropenem in human serum using high-performance liquid chromatography with ultraviolet detection (HPLC/UV) was developed and validated. Meropenem was determined by an isocratic HPLC using a tris(hydroxymethyl)aminomethane buffer (pH 8.5; 15% methanol) as a mobile phase and UV detection at 300 nm, with a flow rate of 1.0 mL/min and an analysis time of 10 min. Chromatographic separation was performed on a Kinetex C18 column (5 μm, 150 × 4.6 mm). In order to remove undesired serum components, solid-phase extraction was used for sample preparation. Since meropenem is not stable in solution, sample and stock solution were stored at -80°C. After preparation, samples were stable at room temperature for at least 6 h. The calibration curve was linear from 3.5 to 200 mg/L with a correlation coefficient r2 of 0.999. The method is accurate with an intra- and inter-assay precision <18.5%. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Using micellar electrokinetic chromatography for the highly efficient preconcentration and separation of gold nanoparticles.

    Science.gov (United States)

    Liu, Fu-Ken

    2009-03-20

    In this paper, we report the use of micellar electrokinetic chromatography (MEKC) for the highly efficient preconcentration and separation of gold nanoparticles (Au NPs). We used the reversed electrode polarity stacking mode (REPSM) of the MEKC system for the on-line enhancement and separation of the Au NPs. Several parameters had dramatic effects on the systems' performance, including the concentration of sodium dodecylsulfate (SDS) surfactant, the presence of salts in the NP solution, the pH of the running electrolyte, and the temperature of the capillary. Under the optimized conditions [buffer: SDS (70 mM) and 3-cyclohexylamino-1-propanesulfonic acid (CAPS; 10 mM) at pH 10.0; applied voltage: 20 kV; operating temperature: 25 degrees C; additive: sodium dihydrogenphosphate (NaH(2)PO(4), 10 mM); REPSM strategy for sample preconcentration], the number of theoretical plates for the 5.3- and 40.1-nm-diameter Au NPs were 3000 and (an ultrahigh) 2.1 x 10(6), respectively; in addition, the detection sensitivities toward the Au NPs were enhanced ca. 20- and 380-fold, respectively, relative to those obtained using standard MEKC analysis conditions. Furthermore, monitoring the electropherograms using diode-array detection allowed us to identify and characterize the sizes of the separated NPs from their UV-vis spectra. Our findings suggest that MEKC is a highly efficient tool for both the preconcentration and separation of NPs.

  2. Quantitative analysis of mitragynine in human urine by high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lu, Shijun; Tran, Buu N; Nelsen, Jamie L; Aldous, Kenneth M

    2009-08-15

    Mitragynine is the primary active alkaloid extracted from the leaves of Mitragyna speciosa Korth, a plant that originates in South-East Asia and is commonly known as kratom in Thailand. Kratom has been used for many centuries for their medicinal and psychoactive qualities, which are comparable to that of opiate-based drugs. Kratom abuse can lead to a detectable content of mitragynine residue in urine. Ultra trace amount of mitragynine in human urine was determined by a high performance liquid chromatography coupled to an electrospray tandem mass spectrometry (HPLC-ESI/MS/MS). Mitragynine was extracted by methyl t-butyl ether (MTBE) and separated on a HILIC column. The ESI/MS/MS was accomplished using a triple quadrupole mass spectrometer in positive ion detection and multiple reactions monitoring (MRM) mode. Ajmalicine, a mitragynine's structure analog was selected as internal standard (IS) for method development. Quality control (QC) performed at three levels 0.1, 1 and 5 ng/ml of mitragynine in urine gave mean recoveries of 90, 109, and 98% with average relative standard deviation of 22, 12 and 16%, respectively. The regression linearity of mitragynine calibration ranged from 0.01 to 5.0 ng/ml was achieved with correlation coefficient greater than 0.995. A detection limit of 0.02 ng/ml and high precision data within-day and between days analysis were obtained.

  3. [Determination of gossypol in edible vegetable oil with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhang, Wenhua; Huang, Chaoqun; Xie, Wen; Shen, Li

    2014-06-01

    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of gossypol in edible vegetable oil. The sample was extracted with ethyl alcohol by vortex-excited oscillation. The extract was cleaned up by 0.22 microm filter membrane and centrifuged for 5 min at 4 000 r/min after standing in a fridge at 4 degrees C for 30 min. The compound was separated on a C18 column (100 mm x 2.1 mm, 3.5 microm) with acetonitrile and 1% (v/v) formic acid aqueous solution as mobile phase. The detection of gossypol was carried out by LC-MS/MS with positive electrospray ionization under multiple reaction monitoring (MRM) mode using external standard method. The limits of quantification (S/N > 10) of gossypol in edible vegetable oil was 1 mg/kg. The recoveries were from 87.4% to 100% at the spiked levels of 1, 2, 200 mg/kg of gossypol in edible vegetable oil with the relative standard deviations (RSDs) between 3.9% and 12.2%. The method, with high sensitivity, good precision and high recovery, was suitable for the confirmation and quantification of gossypol residue in edible vegetable oil.

  4. Reversed-phase high-performance liquid chromatography of tenuazonic acid and related tetramic acids.

    Science.gov (United States)

    Shephard, G S; Thiel, P G; Sydenham, E W; Vleggaar, R; Marasas, W F

    1991-05-03

    A reversed-phase high-performance liquid chromatographic system for the determination of the fungal toxin, tenuazonic acid, (5S,8S)-3-acetyl-5-sec.-butyltetramic acid, is described. The system utilizes a column packed with deactivated end-capped C18 silica with a high carbon load to overcome the problem of poor chromatographic performance of this beta-diketone on reversed-phase liquid chromatography which previously necessitated the use of anion-exchange, ligand-exchange or ion-pairing methods. The reversed-phase system allows the separation of tenuazonic acid from its (5R,8S)-diastereomer, allo-tenuazonic acid and was applied to the detection of tenuazonic acid in cultures of Alternaria alternata and Phoma sorghina. By means of diode-array ultraviolet detection, (5S)-3-acetyl-5-isopropyltetramic acid was observed in extracts of culture material. This metabolite was purified using the analytical reversed-phase system and was identified by 1H and 13C nuclear magnetic resonance spectroscopy.

  5. Determination of 5-methylcytosine from plant DNA by high-performance liquid chromatography.

    Science.gov (United States)

    Wagner, I; Capesius, I

    1981-06-26

    The relative amounts of the five nucleosides (deoxycytidine, 5-methyldeoxycytidine, deoxyadenosine, deoxyguanosine and thymidine) in the DNA of nine plant species, one plant satellite DNA, and one animal species were determined by high performance liquid chromatography. The method allows the clean separation of the nucleosides from 10 microgram samples with 15 min. The following values for the proportion of methylated cytosines among all cytosines were obtained: Lobularia maritima 18.5%, Nicotiana tabacum 32.6%, Pisum sativum 23.2%, Rhinanthus minor 29.2%, Sinapsis alba 12.2%, Vicia faba 30.5%, Viscum album 23.2%, Cymbidium pumilum 18.8%, Cymbidium pumilum AT-rich satellite DNA 15.8%, Triticum aestivum 22.4%. DNA of an animal, the gerbil, Meriones unguiculatus, had a methylation percentage of 3.1%. An estimate of the GC content based on the buoyant density of DNA tends to be lower than the actual value, an estimate based on the melting temperature tends to be higher. This supports the finding by other authors that DNA methylation decreases the buoyant density and may increase the melting temperature at high m5C concentration.

  6. Analysis of serotonin concentrations in human milk by high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Chiba, Takeshi; Maeda, Tomoji; Tairabune, Tomohiko; Tomita, Takashi; Sanbe, Atsushi; Takeda, Rika; Kikuchi, Akihiko; Kudo, Kenzo

    2017-03-25

    Serotonin (5-hydroxytryptamine, 5-HT) plays an important role in milk volume homeostasis in the mammary gland during lactation; 5-HT in milk may also affect infant development. However, there are few reports on 5-HT concentrations in human breast milk. To address this issue, we developed a simple method based on high-performance liquid chromatography with fluorescence detection (HPLC-FD) for measuring 5-HT concentrations in human breast milk. Breast milk samples were provided by four healthy Japanese women. Calibration curves for 5-HT in each sample were prepared with the standard addition method between 5 and 1000 ng/ml, and all had correlation coefficients >0.999. The recovery of 5-HT was 96.1%-101.0%, with a coefficient of variation of 3.39%-8.62%. The range of 5-HT concentrations estimated from the calibration curves was 11.1-51.1 ng/ml. Thus, the HPLC-FD method described here can effectively extract 5-HT from human breast milk with high reproducibility. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Methacrylate-bonded covalent-organic framework monolithic columns for high performance liquid chromatography.

    Science.gov (United States)

    Liu, Li-Hua; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2017-01-06

    Covalent-organic frameworks (COFs) are a newfangled class of intriguing microporous materials. Considering their unique properties, COFs should be promising as packing materials for high performance liquid chromatography (HPLC). However, the irregular shape and sub-micrometer size of COFs synthesized via the traditional methods render the main obstacles for the application of COFs in HPLC. Herein, we report the preparation of methacrylate-bonded COF monolithic columns for HPLC to overcome the above obstacles. The prepared COF bonded monolithic columns not only show good homogeneity and permeability, but also give high column efficiency, good resolution and precision for HPLC separation of small molecules including polycyclic aromatic hydrocarbons, phenols, anilines, nonsteroidal anti-inflammatory drugs and benzothiophenes. Compared with the bare polymer monolithic column, the COF bonded monolithic columns show enhanced hydrophobic, π-π and hydrogen bond interactions in reverse phase HPLC. The results reveal the great potential of COF bonded monoliths for HPLC and COFs in separation sciences. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Analysis of Drug Interactions with Lipoproteins by High-Performance Affinity Chromatography

    Science.gov (United States)

    Sobansky, Matthew R.; Hage, David S.

    2013-01-01

    Lipoproteins such as high-density lipoprotein (HDL) and low-density lipoprotein (LDL) are known to interact with drugs and other solutes in blood. These interactions have been examined in the past by methods such as equilibrium dialysis and capillary electrophoresis. This chapter describes an alternative approach that has recently been developed for examining these interactions by using high-performance affinity chromatography. In this method, lipoproteins are covalently immobilized to a solid support and used within a column as a stationary phase for binding studies. This approach allows the same lipoprotein preparation to be used for a large number of binding studies, leading to precise estimates of binding parameters. This chapter will discuss how this technique can be applied to the identification of interaction models and be used to differentiate between systems that have interactions based on partitioning, adsorption or mixed-mode interactions. It is also shown how this approach can then be used for the measurement of binding parameters for HDL and LDL with drugs. Examples of these studies are provided, with particular attention being given to the use of frontal analysis to examine the interactions of R- and S-propranolol with HDL and LDL. The advantages and possible limitations of this method are described. The extension of this approach to other types of drug-lipoprotein interactions is also considered. PMID:25392741

  9. Simultaneous Determination of Four Preservatives in Foodstuffs by High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Mohammad Faraji

    2016-04-01

    Full Text Available Background and objectives:  High concentration of preservatives in food may result in gastrointestinal disturbances whereby some patients suffering from asthma, rhinitis, or urticaria. The aim of this study is the introduction and optimization a new method for simultaneous determination of four preservatives (SB, PS, MP, PP in foodstuff by high performance liquid chromatography. Materials and methods: Important factors in extraction, separation and determination process were optimized using the one variable at a time method.  Figures of merit of the proposed method were evaluated. The amount of SB, PS, MP, PP in some food samples were determined using the proposed method. Result: The results showed that the obtained chromatogram of extract was free of significant interferences. The preservatives recoveries ranged from 88% to 110 %. Concentration of SB, PS, MP and PP in the 20studied samples ranges between N.D-639.9, N.D -214.5, N.D -579.8 and N.D -30.5 mg kg-1, respectively  Conclusion: The performance and reliability of proposed method as a simple, efficient and fast method for determination of SB, PS, MP, PP in the food samples was demonstrated.

  10. HPTLC-aptastaining - Innovative protein detection system for high-performance thin-layer chromatography

    Science.gov (United States)

    Morschheuser, Lena; Wessels, Hauke; Pille, Christina; Fischer, Judith; Hünniger, Tim; Fischer, Markus; Paschke-Kratzin, Angelika; Rohn, Sascha

    2016-05-01

    Protein analysis using high-performance thin-layer chromatography (HPTLC) is not commonly used but can complement traditional electrophoretic and mass spectrometric approaches in a unique way. Due to various detection protocols and possibilities for hyphenation, HPTLC protein analysis is a promising alternative for e.g., investigating posttranslational modifications. This study exemplarily focused on the investigation of lysozyme, an enzyme which is occurring in eggs and technologically added to foods and beverages such as wine. The detection of lysozyme is mandatory, as it might trigger allergenic reactions in sensitive individuals. To underline the advantages of HPTLC in protein analysis, the development of innovative, highly specific staining protocols leads to improved sensitivity for protein detection on HPTLC plates in comparison to universal protein derivatization reagents. This study aimed at developing a detection methodology for HPTLC separated proteins using aptamers. Due to their affinity and specificity towards a wide range of targets, an aptamer based staining procedure on HPTLC (HPTLC-aptastaining) will enable manifold analytical possibilities. Besides the proof of its applicability for the very first time, (i) aptamer-based staining of proteins is applicable on different stationary phase materials and (ii) furthermore, it can be used as an approach for a semi-quantitative estimation of protein concentrations.

  11. Determination of nucleosides in Cordyceps sinensis and Ganoderma lucidum by high performance liquid chromatography method

    Directory of Open Access Journals (Sweden)

    Masood Shah Khan

    2015-01-01

    Full Text Available Background: Nucleosides are supportive in the regulation and modulation of various physiological processes in body, they acts as precursors in nucleic acid synthesis, enhance immune response, help in absorption of iron and influence the metabolism of fatty acids. Cordyceps sinensis and Ganoderma lucidum are well-known for its use in traditional medicine of China, Nepal and India. They are rich in nucleosides such as adenine, adenosine, cordycepin, etc. Hence, a simple, economic and accurate high-performance liquid chromatography (HPLC analytical method was proposed for determination of adenine and adenosine for the quality control of plants. Materials and Methods: Chromatographic experiments were conducted on YL9100 HPLC system (South Korea. Reversed-phase chromatography was performed on a C18 column with methanol and dihydrogen phosphate as the mobile phase in isocratic elution method at a flow rate of 1.0 mL/min. Detection was carried out at 254 nm, which gives a sharp peak of adenine and adenosine at a retention time of 6.53 ± 0.02 min and 12.41 ± 0.02, respectively. Results and Discussion: Linear regression analysis data for the calibration plot showed a good linear relationship between response and concentration in the range of 25–200 µg/mL for adenosine and 100–800 µg/mL for adenine with regression coefficient of 0.999 and 0.996, respectively. The adenine was found 0.16% and 0.71% w/w in G. lucidum and in C. sinensis, respectively, and adenosine was found to be 0.14% w/w in G. lucidum whereas absent in C. sinensis. Conclusion: The developed HPLC method for the quantification of adenosine and adenine can be used for the quality control and standardization of crude drug and for the different herbal formulations, in which adenine and adenosine are present as major constituents. The wide linearity range, sensitivity, accuracy, and simple mobile phase imply the method is suitable for routine quantification of adenosine and adenine with

  12. Instrumental liquid chromatography: a practical manual on high-performance liquid chromatographic methods

    National Research Council Canada - National Science Library

    Parris, N. A

    1976-01-01

    Available texts on liquid chromatography have tended to emphasize the developments in the theoretical understanding of the technique and methodology or to list numerous applications, complete with experimental details...

  13. Gelatin quantification by oxygen-18 labeling and liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Sha, Xiao-Mei; Tu, Zong-Cai; Wang, Hui; Huang, Tao; Duan, Deng-Le; He, Na; Li, De-Jun; Xiao, Hui

    2014-12-10

    Combined with high-performance liquid chromatography (HPLC) and linear-ion trap/Orbitrap high-resolution mass spectrometry, trypsin-catalyzed (16)O-to-(18)O exchange was used to establish an accurate quantitative method for bovine or porcine gelatin. The sophisticated modifications for these two mammalian gelatins were unambiguously identified by accurate mass and tandem mass spectrometry. Eighteen marker peptides were successfully identified for the bovine and porcine gelatin, respectively. The gelatins were subjected to (18)O or (16)O labeling in the presence of trypsin and mixed together in various ratios for quantification. All of the (18)O-labeled peptides were also confirmed by accurate mass and tandem mass spectrometry. The 10 marker peptides with the strongest signals were chosen to calculate the average ratios of (18)O-labeled and (16)O-labeled gelatin. The measured ratios of (18)O-labeled and (16)O-labeled peptides were very close to the mixing ratios of 20:1, 5:1, 1:1, and 1:5 with low standard deviation values. The samples with a mixing ratio of 1:1 (18)O-labeled and (16)O-labeled peptides were determined to 1.00 and 0.99 with standard deviations of 0.02 and 0.04 for bovine and porcine gelatins, respectively, indicating the high accuracy of this method. Trypsin-catalyzed (18)O labeling was proved to be an excellent internal calibrant for gelatins. When combined with HPLC and high-resolution mass spectrometry, it is an accurate and sensitive quantitative method for gelatin in the food industry.

  14. High-resolution, preparative purification of PEGylated protein using a laterally-fed membrane chromatography device.

    Science.gov (United States)

    Madadkar, Pedram; Nino, Sergio Luna; Ghosh, Raja

    2016-11-01

    We discuss the use of a laterally-fed membrane chromatography (or LFMC) device for single-step purification of mono-PEGylated lysozyme. Recent studies have shown such LFMC devices to be suitable for high-resolution, multi-component separation of proteins in the bind-and-elute mode. The device used in this study contained a stack of rectangular cation-exchange membranes having 9.25mL bed volume. PEGylation of lysozyme was carried out in batch mode using 5kDa methoxy-polyethyleneglycol propionaldehyde (or m-PEG propionaldehyde) in the presence of sodium cyanoborohydride as reducing agent. Membrane chromatographic separation was carried out at 1.62 membrane bed volumes per minute flow rate, in the bind-and-elute mode. When a salt gradient was applied, the higher PEGylated forms of lysozyme (i.e. the byproducts) eluted earlier than mono-PEGylated lysozyme (the target product), while lysozyme eluted last. Under elution conditions optimized for resolution and speed, the separation could be carried out in less than 15 membrane bed volumes. High purity and recovery of mono-PEGylated lysozyme was obtained. The resolution of separation of mono-PEGylated lysozyme obtained under the above condition was comparable to that reported in the literature for equivalent cation-exchange resin columns while the flow rate expressed in bed volumes/min was 21.7 times higher. Also, the number of theoretical plates per meter was significantly higher with the LFMC device. Therefore the LFMC based purification process discussed in this paper combined high-productivity with high-resolution. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Analysis of rabbit tear proteins by high-pressure liquid chromatography/electrospray ionization mass spectrometry.

    Science.gov (United States)

    Zhou, Lei; Beuerman, Roger W; Barathi, Amutha; Tan, Donald

    2003-01-01

    The aim of this study was to develop a fast and reliable analytical procedure for the display of the protein components of tears that can be used to differentiate the status of the ocular surface. Using this new procedure, we analyzed the tear protein components following a corneal wound in the rabbit. Calibrated 10-microL glass, fire-polished capillary micropipettes were used to collect tears from New Zealand White rabbits prior to and daily for 9 days following a unilateral 6-mm diameter centrally placed anterior keratectomy. Tear proteins were eluted by a reversed-phase high-performance liquid chromatography (RP-HPLC) column and the tear protein profile was monitored by electrospray ionization (ESI) mass spectrometry positive total ion current (TIC) chromatography. Tear proteins were reliably separated into 17 peaks, each of which contained one or a number of protein components. The molecular weight of each protein component was determined by on-line ESI. Major tear protein components, lactoferrin, lysozyme (minimally detectable in rabbit tears), albumin, lipocalin, lipophilin and beta2-microglobulin, were tentatively identified by this method. Based on the mass spectrometric data, beta2-microglobulin was found to be glycosylated with N-acetylhexosamine. ESI-positive TIC chromatograms and mass spectra revealed comparative differences in the tear protein spectra after corneal wounding. One day after wounding, rabbit lysozyme with a molecular weight of 14,717 Da was found to be 8-fold higher in the tears of wounded eyes when compared with tears from unwounded eyes. It dropped back to normal 3 days after wounding. The expression of an unidentified tear protein with the molecular weight of 16,060 Da was also elevated after corneal wounding and returned to normal level by day 5. In this study, LC/ESI-MS was developed as a fast, reproducible and simple method for the identification and analysis of many of the protein components of the tears. Importantly, this

  16. Separation and purification of 9,10-dihydrophenanthrenes and bibenzyls from Pholidota chinensis by high-speed countercurrent chromatography.

    Science.gov (United States)

    Chen, Yang; Cai, Shining; Deng, Liang; Xia, Qiang; Du, Lian-Feng; Cui, Guo-Zhen; Li, Jun; Zhou, Xu-Mei; Ye, Qizhang; Zhou, Yan; Lin, Mao

    2015-02-01

    Stilbenoids are the main components of leaves and stems of Pholidota chinensis. In the present investigation, high-speed counter-current chromatography was used for the separation and purification of two classes of stilbenoids, namely, bibenzyls and 9,10-dihydrophenanthrenes, on a preparative scale from whole plants of P. chinensis with different solvent systems after silica gel column chromatography fractionation. n-Hexane/ethyl acetate/methanol/water (1.2:1:1:0.8, v/v/v/v) was selected as the optimum solvent system to purify 1-(3,4,5-trimethoxyphenyl)-1',2'-ethanediol (1), coelonin (2), 3,4'-dihydroxy-5,5'-dimethoxybibenzyl (3), and 2,​7-​dihydroxy-​3,​4,​6-​trimethoxy-​9,​10-​dihydrophenanthrene (4). While 2,7-dihydroxy-3,4,6-trimethoxy-​9,​10-​dihydrophenanthrene (5), batatasin III (6), orchinol (7), and 3'-O-methylbatatasin III (8) were purified by n-hexane/ethyl acetate/methanol/water (1.6:0.8:1.2:0.4, v/v/v/v). After the high-speed counter-current chromatography isolation procedure, the purity of all compounds was over 94% assayed by ultra high performance liquid chromatography. The chemical structure identification of all compounds was carried out by mass spectrometry and (1)H and (13)C NMR spectroscopy. To the best of our knowledge, the current investigation is the first study for the separation and purification of bibenzyls and 9,10-dihydrophenanthrenes by high-speed counter-current chromatography from natural resources. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Preparative separation of cacao bean procyanidins by high-speed counter-current chromatography.

    Science.gov (United States)

    Li, Lingxi; Zhang, Shuting; Cui, Yan; Li, Yuanyuan; Luo, Lanxin; Zhou, Peiyu; Sun, Baoshan

    2016-11-15

    In this work, an efficient method for preparative separation of procyanidins from raw cacao bean extract by high-speed counter-current chromatography (HSCCC) was developed. Under the optimized solvent system of n-hexane-ethyl acetate-water (1:50:50, v/v/v) with a combination of head-tail and tail-head elution modes, various procyanidins fractions with different polymerization degrees were successfully separated. UPLC, QTOF-MS and 1H NMR analysis verified that these fractions contained monomer up to pentamer respectively. Dimeric procyanidin B2 (purity>86%) could be isolated by HSCCC in a single run. Other individual procyanidins in these fractions could be further isolated and purified by preparative HPLC. The developed HSCCC together with preparative HPLC techniques appeared to be a useful tool for large preparation of different procyanidins from cacao beans. Furthermore, by antioxidant activity assays, it was proved that both fractions and individual procyanidins possessed greater antioxidant activities compared to standard trolox. The antioxidant activities of procyanidins increase as the increase of their polymerization degree. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. [Determination of three isothiazolinone biocides in water-borne adhesives by high performance liquid chromatography].

    Science.gov (United States)

    Zhou, Xiao; Li, Xiaolan; Chen, Zhiyan; Ye, Changwen; Zhou, Yun; Meng, Dongling

    2015-01-01

    A rapid high performance liquid chromatography (HPLC) method was developed for the quantitative analysis of three isothiazolinone biocides (2-methyl-4-isothiazolin-3-one (MI), 5-chloro-2-methyl-4-isothiazolin-3-one (CMI) and 1, 2-benzylisothiazolin-3-one (BIT)) in water-borne adhesives. The sample was extracted with methanol-water (1:1, v/v), and purified by centrifugation and filtration. The isothiazolones were separated on a C18 column with methanol-water as mobile phases under gradient elution and detected with a diode array detector (DAD). The pretreatment factors such as extraction solvent, extraction method, dilution ratio, extraction time were optimized. Under the optimized conditions, the targets had good linearities (r2H > or = 0.9992) in the range of 0.25-10.0 mg/L. The recoveries were between 92% and 103% with the relative standard deviations not more than 4%. The limits of detection (LODs) were between 0.43 mg/kg and 1.14 mg/kg. The limits of quantification (LOQs) were between 1.44 mg/kg and 3.81 mg/kg. The results showed that the method can achieve the purpose of quantitative detection. The analyses of real samples verified the reliability of this method.

  19. Simultaneous quantification of five major biologically active ingredients of saffron by high-performance liquid chromatography.

    Science.gov (United States)

    Li, N; Lin, G; Kwan, Y W; Min, Z D

    1999-07-23

    A simple, sensitive and specific high-performance liquid chromatography-UV (HPLC-UV) method has been developed for the first time to simultaneously quantify the five major biologically active ingredients of saffron, namely crocin 1, crocin 2, crocin 3, crocin 4 and crocetin. Calibration curves were derived by spiking authentic compounds and internal standard, 13-cis-retinoic acid, into herbal samples prior to extraction. Extraction was conducted simply by stirring dried herb (20 mg) with 80% aqueous methanol (5 ml) at ambient temperature in the dark for 2 h. The HPLC assay was performed on a reversed-phase C18 column with linear gradient elution using methanol and 1% aqueous acetic acid. Calibrations were linear (r2 = 0.999) for all five analytes, with overall intra- and inter-day RSDs of less than 11%. The assay was successfully applied to the determination of four crocins and crocetin in three saffron samples and two Zhizi, another crocin-containing herb. Results indicate that the developed HPLC assay can be readily utilized as a quality control method for crocin-containing medicinal herbs.

  20. Determination of drug lipophilicity by phosphatidylcholine-modified microemulsion high-performance liquid chromatography.

    Science.gov (United States)

    Xuan, Xueyi; Xu, Liyuan; Li, Liangxing; Gao, Chongkai; Li, Ning

    2015-07-25

    A new biomembrane-mimetic liquid chromatographic method using a C8 stationary phase and phosphatidylcholine-modified (PC-modified) microemulsion mobile phase was used to estimate unionized and ionized drugs lipophilicity expressed as an n-octanol/water partition coefficient (logP and logD). The introduction of PC into sodium dodecyl sulfate (SDS) microemulsion yielded a good correlation between logk and logD (R(2)=0.8). The optimal composition of the PC-modified microemulsion liquid chromatography (PC-modified MELC) mobile phase was 0.2% PC-3.0% SDS-6.0% n-butanol-0.8% ethyl acetate-90.0% water (pH 7.0) for neutral and ionized molecules. The interactions between the analytes and system described by this chromatographic method is more similar to biological membrane than the n-octanol/water partition system. The result in this paper suggests that PC-modified MELC can serve as a possible alternative to the shake-flask method for high-throughput unionized and ionized drugs lipophilicity determination and simulation of biological processes. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Comparative determination of phenytoin in plasma by fluorescence polarization immunoassay and high performance liquid chromatography.

    Science.gov (United States)

    Othman, S; al-Turk, W A; Awidi, A S; Daradkeh, T K; Shaheen, O

    1987-09-01

    The need for careful monitoring of plasma concentrations of phenytoin during use of the drug in the treatment of epilepsy is well recognized; there can be great intersubject variation in the absorption rate and clearance rate of the drug, and its therapeutic ratio is narrow. In this study, two methods for determining plasma phenytoin concentrations were compared. One, based on fluorescence polarisation immunoassay (FPIA), is utilised in a commercially-available kit. The other, our own modification of a published procedure, was based on high performance liquid chromatography (HPLC). The accuracy and precision of both methods were evaluated, and the coefficients of variation (C.V.) were calculated. The C.V.'s ranged from 0.71 to 1.86% for the FPIA method, and from 2.81 to 8.69% for the HPLC method. Corresponding bias values were 1.20 to 1.60%, and 2.81 to 8.69%, respectively. A good correlation coefficient (0.977) was obtained, but estimated phenytoin concentrations were significantly higher (95% confidence level) using the HPLC method. We conclude that both methods perform adequately for clinical purposes. The HPLC method is, however, less expensive than the FPIA method.

  2. Anionic forensic signatures for sample matching of potassium cyanide using high performance ion chromatography and chemometrics.

    Science.gov (United States)

    Fraga, Carlos G; Farmer, Orville T; Carman, April J

    2011-01-30

    Potassium cyanide was used as a model toxicant to determine the feasibility of using anionic impurities as a forensic signature for matching cyanide salts back to their source. In this study, portions of eight KCN stocks originating from four countries were separately dissolved in water and analyzed by high performance ion chromatography (HPIC) using an anion exchange column and conductivity detection. Sixty KCN aqueous samples were produced from the eight stocks and analyzed for 11 anionic impurities. Hierarchal cluster analysis and principal component analysis were used to demonstrate that KCN samples cluster according to source based on the concentrations of their anionic impurities. The Fisher-ratio method and degree-of-class separation (DCS) were used for feature selection on a training set of KCN samples in order to optimize sample clustering. The optimal subset of anions needed for sample classification was determined to be sulfate, oxalate, phosphate, and an unknown anion named unk5. Using K-nearest neighbors (KNN) and the optimal subset of anions, KCN test samples from different KCN stocks were correctly determined to be manufactured in the United States. In addition, KCN samples from stocks manufactured in Belgium, Germany, and the Czech Republic were all correctly matched back to their original stocks because each stock had a unique anionic impurity profile. The application of the Fisher-ratio method and DCS for feature selection improved the accuracy and confidence of sample classification by KNN. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Determination of Decabrominated Diphenyl Ether in Soils by Soxhlet Extraction and High Performance Liquid Chromatography

    Science.gov (United States)

    Yang, Xing-Jian; Dang, Zhi; Zhang, Fang-Li; Lin, Zhao-Ying; Zou, Meng-Yao; Tao, Xue-Qin; Lu, Gui-Ning

    2013-01-01

    This study described the development of a method based on soxhlet extraction combining high performance liquid chromatography (soxhlet-HPLC) for the accurate detection of BDE-209 in soils. The solvent effect of working standard solutions in HPLC was discussed. Results showed that 1 : 1 of methanol and acetone was the optimal condition which could totally dissolve the BDE-209 in environmental samples and avoid the decrease of the peak area and the peak deformation difference of BDE-209 in HPLC. The preliminary experiment was conducted on the configured grassland (1 μg/g) to validate the method feasibility. The method produced reliable reproducibility, simulated soils (n = 4) RSD 1.0%, and was further verified by the analysis e-waste contaminated soils, RSD range 5.9–11.4%. The contamination level of BDE-209 in burning site was consistent with the previous study of Longtang town but lower than Guiyu town, and higher concentration of BDE-209 in paddy field mainly resulted from the long-standing disassembling area nearby. This accurate and fast method was successfully developed to extract and analyze BDE-209 in soil samples, showing its potential use for replacing GC to determinate BDE-209 in soil samples. PMID:24302876

  4. Is high pressure liquid chromatography an effective screening tool for characterization of molecular defects in hemoglobinopathies?

    Science.gov (United States)

    Moorchung, Nikhil; Phillip, Joseph; Sarkar, Ravi Shankar; Prasad, Rupesh; Dutta, Vibha

    2013-01-01

    Hemoglobinopathies constitute entities that are generated by either abnormal hemoglobin or thalassemias. high pressure liquid chromatography (HPLC) is one of the best methods for screening and detection of various hemoglobinopathies but it has intrinsic interpretive problems. The study was designed to evaluate the different mutations seen in cases of hemoglobinopathies and compare the same with screening tests. 68 patients of hemoglobinopathies were screened by HPLC. Mutation studies in the beta globin gene was performed using the polymerase chain reaction (PCR)-based allele-specific Amplification Refractory Mutation System (ARMS). Molecular analysis for the sickle cell mutation was done by standard methods. The IVS 1/5 mutation was the commonest mutation seen and it was seen in 26 (38.23%) of the cases. This was followed by the IVS 1/1, codon 41/42, codon 8/9, del 22 mutation, codon 15 mutation and the -619 bp deletion. No mutation was seen in eight cases. There was a 100% concordance between the sickle cell trait as diagnosed by HPLC and genetic testing. Our study underlies the importance of molecular testing in all cases of hemoglobinopathies. Although HPLC is a useful screening tool, molecular testing is very useful in accurately diagnosing the mutations. Molecular testing is especially applicable in cases with an abnormal hemoglobin (HbD, HbE and HbS) because there may be a concomitant inheritance of a beta thalassemia mutation. Molecular testing is the gold standard when it comes to the diagnosis of hemoglobinopathies.

  5. Identification and Quantitation of Asparagine and Citrulline Using High-Performance Liquid Chromatography (HPLC

    Directory of Open Access Journals (Sweden)

    Cheng Bai

    2007-01-01

    Full Text Available High-performance liquid chromatography (HPLC analysis was used for identification of two problematic ureides, asparagine and citrulline. We report here a technique that takes advantage of the predictable delay in retention time of the co-asparagine/citrulline peak to enable both qualitative and quantitative analysis of asparagine and citrulline using the Platinum EPS reverse-phase C18 column (Alltech Associates. Asparagine alone is eluted earlier than citrulline alone, but when both of them are present in biological samples they may co-elute. HPLC retention times for asparagine and citrulline were influenced by other ureides in the mixture. We found that at various asparagines and citrulline ratios [= 3:1, 1:1, and 1:3; corresponding to 75:25, 50:50, and 25:75 (μMol ml–1/μMol ml–1], the resulting peak exhibited different retention times. Adjustment of ureide ratios as internal standards enables peak identification and quantification. Both chemicals were quantified in xylem sap samples of pecan [Carya illinoinensis (Wangenh. K. Koch] trees. Analysis revealed that tree nickel nutrition status affects relative concentrations of Urea Cycle intermediates, asparagine and citrulline, present in sap. Consequently, we concluded that the HPLC methods are presented to enable qualitative and quantitative analysis of these metabolically important ureides.

  6. Optimization of parameters of high-performance displacement chromatography for separation of soybean phosphatidylcholine and phosphatidylethanolamine.

    Science.gov (United States)

    Zhang, Wei-Nong; Hu, Zhi-Xiong; Feng, Yu-Qi; Da Shi-Lu

    2005-03-18

    Hundred milligrams of soybean phospholipids were successfully separated by using high-performance displacement chromatography (HPDC) on a 150mm x 4.6mm analytical silica column (3-5 microm packings) with dichloromethane-methanol (9:1, v/v) as carrier and ethanolamine as displacer. From the viewpoint of preparative separation, the effects of loading amount, concentration and flow-rate of displacer on separation efficiency were investigated using throughput and recovery as indices. The parameters were optimized by orthogonal test design and statistical analysis method. Under the optimum conditions, namely displacer concentration being 167 mM, the flow-rate of displacer at 0.2 ml/min and concentration of sample being 211 mg/ml (factual loading amount 211 mg/ml x 0.7 ml = 148 mg), the purity, throughput and recovery of obtained soybean phosphatidylethanolamine (PE) and phosphatidylcholine (PC) were 80.2%, 65.7 mg/h, 70.9% and 90.5%, 272.6 mg/h, 88.3%, respectively. In addition, selections of regenerant and appropriate regeneration condition were also studied.

  7. A validated new method for nevirapine quantitation in human plasma via high-performance liquid chromatography.

    Science.gov (United States)

    Silverthorn, Courtney F; Parsons, Teresa L

    2006-01-01

    A fully validated and clinically relevant assay was developed for the assessment of nevirapine concentrations in neonate blood plasma samples. Solid-phase extraction with an acid-base wash series was used to prepare subject samples for analysis. Samples were separated by high performance liquid chromatography and detected at 280 nm on a C8 reverse-phase column in an isocratic mobile phase. The retention times of nevirapine and its internal standard were 5.0 and 6.9 min, respectively. The method was validated by assessment of accuracy and precision (statistical values 0.996) and the average recovery was 93% (n = 18). The lower limit of quantification (relative standard deviation <20%) was determined to be 25 ng/mL for 50 microL of plasma, allowing detection of as little as 1.25 ng of nevirapine in a sample. This value represents an increase in sensitivity of up to 30-fold over previously published methods. Copyright 2005 John Wiley & Sons, Ltd.

  8. Analysis of Fluconazole in Human Urine Sample by High Performance Liquid Chromatography Method

    Science.gov (United States)

    Hermawan, D.; Ali, N. A. Md; Ibrahim, W. A. Wan; Sanagi, M. M.

    2013-04-01

    A method for determination of fluconazole, antifungal drug in human urine by using reversed-phased high performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detector was developed. Optimization HPLC conditions were carried out by changing the flow rate and composition of mobile phase. The optimum separation conditions at a flow rate 0.85 mL/min with a composition of mobile phase containing methanol:water (70:30, v/v) with UV detection at a wavelength 254 nm was able to analyze fluconazole within 3 min. The excellent linearity was obtained in the range of concentration 1 to 10 μg/mL with r2 = 0.998. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.39 μg/mL and 1.28 μg/mL, respectively. Solid phase extraction (SPE) method using octadecylsilane (C18) as a sorbent was used to clean-up and pre-concentrated of the urine sample prior to HPLC analysis. The average recoveries of fluconazole in spiked urine sample was 72.4% with RSD of 3.21% (n=3).

  9. Determination of isotopically labelled monoesterphthalates in urine by high performance liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Anderson, Warwick A C; Barnes, Karen A; Castle, Laurence; Damant, Andrew P; Scotter, Michael J

    2002-09-01

    A method of analysis for monoesters of phthalic acid ('monoesterphthalates') in human urine has been developed. The method was needed to determine the hydrolysis and excretion efficiency of isotopically-labelled phthalate diesters ('phthalates') when they were fed to volunteers as part of a biomarker study to estimate total exposure to phthalates. The targeted substances were 13C-monobutylphthalate (MBP), 2H4-monobutylphthalate (MBP), 2H4-monobenzylphthalate (MBeP), 13C-monocyclohexylphthalate (MCHP), 13C-monoethylhexylphthalate (MEHP), and 13C-monoisodecylphthalate (MIDP). The monoesters in urine were deconjugated enzymatically, extracted into solvent, and then determined by high performance liquid chromatography-mass spectrometry (LC-MS) using atmospheric pressure chemical ionisation in the negative ion mode. The limits of determination were 10 ng ml(-1) for MBP, MCHP, MBeP and MEHP, and 40 ng ml(-1) for MIDP. The recovery from urine spiked at 100 ng ml(-1) was in the range from 70 to 85% except for MIDP which was lower at 55%. The between-batch reproducibility of the analysis was in the range 8 to 17% (n = 6 batches on separate days).

  10. Detection of HEMA in self-etching adhesive systems with high performance liquid chromatography

    Science.gov (United States)

    Panduric, V.; Tarle, Z.; Hameršak, Z.; Stipetić, I.; Matosevic, D.; Negovetić-Mandić, V.; Prskalo, K.

    2009-04-01

    One of the factors that can decrease hydrolytic stability of self-etching adhesive systems (SEAS) is 2-hydroxymethylmethacrylate (HEMA). Due to hydrolytic instability of acidic methacrylate monomers in SEAS, HEMA can be present even if the manufacturer did not include it in original composition. The aim of the study was to determine the presence of HEMA because of decomposition by hydrolysis of methacrylates during storage, resulting with loss of adhesion strength to hard dental tissues of the tooth crown. Three most commonly used SEAS were tested: AdheSE ONE, G-Bond and iBond under different storage conditions. High performance liquid chromatography analysis was performed on a Nucleosil C 18-100 5 μm (250 × 4.6 mm) column, Knauer K-501 pumps and Wellchrom DAD K-2700 detector at 215 nm. Data were collected and processed by EuroCrom 2000 HPLC software. Calibration curves were made related eluted peak area to known concentrations of HEMA (purchased from Fluka). The elution time for HEMA is 12.25 min at flow rate 1.0 ml/min. Obtained results indicate that no HEMA was present in AdheSE ONE because methacrylates are substituted with methacrylamides that seem to be more stable under acidic aqueous conditions. In all other adhesive systems HEMA was detected.

  11. Simultaneous determination of 11 preservatives in cosmetics by high-performance liquid chromatography.

    Science.gov (United States)

    Aoyama, Airin; Doi, Takahiro; Tagami, Takaomi; Kajimura, Keiji

    2014-10-01

    Preservatives prevent the growth of microorganisms in foods, pharmaceuticals and cosmetics. There exist numerous restrictions regarding the maximum allowable levels of preservatives in cosmetics. We analyzed 11 regulated preservatives in commercial cosmetics and manufacturers need to analyze their products for quality control purposes. However, methods used in previous studies to date have been inadequate for use by public institutions and manufacturers. Therefore, an effective, scalable method for the analysis of preservatives in cosmetics is required. We developed a novel method for the simultaneous determination of 11 regulated preservatives in cosmetics by high-performance liquid chromatography (HPLC). We applied the samples to a C18 column in a simple mobile phase (5 mmol/L ammonium formate solution and acetonitrile) with gradient elution at a flow rate of 1.0 mL/min at a single wavelength (230 nm). The correlation coefficients of the calibration curves were >0.997. The percent recoveries were 92.8-111.9% and the relative standard deviations were 1.9. Because of the simple conditions for isolation and complete separation, the HPLC method can be effectively applied to the analysis of preservatives in commercially retailed cosmetics. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Quantitative Determination of Compounds from Akebia quinata by High-Performance Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Nguyen; Thu, Nguyen; Zhao, Bing Tian; Woo, Mi Hee; Min, Byung Sun [Catholic Univ. of Daegu, Gyeongsan (Korea, Republic of); Lee, Jae Hyun [Dongguk Univ., Yongin (Korea, Republic of); Kim, Jeong Ah [Kyungpook National Univ., Daegu (Korea, Republic of); Son, Jong Keun [Yeungnam Univ., Gyeongsan (Korea, Republic of); Choi, Jae Sui [Pukyung National Univ., Busan (Korea, Republic of); Woo, Eun Rhan [Chosun Univ., Gwangju (Korea, Republic of)

    2014-07-15

    To provide the scientific corroboration of the traditional uses of Akebia quinata (Thunb.) Decne., a detailed analytical examination of A. quinata stems was carried out using a reversed-phase high performance liquid chromatography (RP-HPLC) method coupled to photodiode array detector (PDA) for the simultaneous determination of four phenolic substances; cuneataside D, 2-(3,4-dihydroxyphenyl)ethyl-O-β-D-glucopyranoside, 3-caffeoylquinic acid and calceolarioside B. Particular attention was focused on the main compound, 3-caffeoylquinic acid, which has a range of biological functions. In addition, 2-(3,4-dihydroxyphenyl)ethyl-O-β-D-glucopyranoside was considered as a discernible marker of A. quinata from its easy confuse plants. The contents of compounds 2 and 3 ranged from 0.72 to 2.68 mg/g and from 1.66 to 5.64 mg/g, respectively. The validation data indicated that this HPLC/PDA assay was used successfully to quantify the four phenolic compounds in A. quinata from different locations using relatively simple conditions and procedures. The pattern-recognition analysis data from 53 samples classified them into two groups, allowing discrimination between A. quinata and comparable herbs. The results suggest that the established HPLC/PDA method is suitable for quantitation and pattern-recognition analyses for a quality evaluation of this medicinal herb.

  13. Rapid Analysis of Cefazolin in Serum by High-Pressure Liquid Chromatography

    Science.gov (United States)

    Wold, John S.

    1977-01-01

    A high-pressure liquid chromatography (HPLC) method has been developed for the analysis of cefazolin in serum. Serum was deproteinized by the addition of 6% trichloroacetic acid and injected onto a reverse-phase column with a mobile phase of 10 to 15% methanol in 1% aqueous acetic acid. Cefazolin chromatographed without interference from ultraviolet-absorbing components of serum, with a retention time of 3.1 min. Standard curves comparing peak area with concentration prepared from dog or human sera were linear over a range of 1.6 to 200 μg/ml. Results from the HPLC assay were compared with microbiological assays (cylinder plate method) on both standard serum samples and sera from dogs and human subjects receiving intramuscular cefazolin. The HPLC method was somewhat more accurate in comparison with the microbiological assay performed on serum samples of known concentration. The comparison of results from an analysis of serum levels of dogs or human subjects receiving cefazolin indicated that the two methods would lead to identical conclusions concerning pharmacokinetics or the achievement of therapeutic serum levels. The HPLC assay method presents an alternative to conventional microbiological assays, with marked improvement in speed (30 min) and considerable potential for future development. PMID:836007

  14. Determination of miloxacin and metabolites in human serum and urine by high-pressure liquid chromatography.

    Science.gov (United States)

    Yoshitake, A; Kawahara, K; Shono, F; Umeda, I; Izawa, A; Komatsu, T

    1980-01-01

    A sensitive and reliable high-pressure liquid chromatography (HPLC) assay for miloxacin and its two principal metabolites, 5,8-dihydro-8-oxo-2H-1,3-dioxolo[4,5-g]quinoline-7-carboxylic acid (M-1) and 1,4-dihydro-1,6-dimethoxy-7-hydroxy-4-oxoquinoline-3-carboxylic acid (M-2), in human serum and urine was developed. A strong anion-exchange Zipax SAX column using a mobile phase of 0.01 M citric acid solution containing 0.03 M sodium nitrate with pH 5.0 was used to achieve separation of the three compounds. The retention times of miloxacin, M-1, and M-2 were 3.8, 9.3, and 5.9 min, respectively. Serum and urine concentrations of these compounds as low as 10 ng/ml were measured. When results from the HPLC assay were compared with those from the microbiological assay of serum and urine samples from human subjects receiving miloxacin orally, the correlation coefficients were 0.94 for the serum and 0.99 for the urine. The HPLC assay method presents an alternative to the microbiological assay and permits future pharmacokinetic investigations of miloxacin. PMID:7416751

  15. Simultaneous determination of eleven characteristic lignans in Schisandra chinensis by high-performance liquid chromatography.

    Science.gov (United States)

    Hu, Junyang; Mao, Chunqin; Gong, Xiaodong; Lu, Tulin; Chen, Han; Huang, Zhijun; Cai, Baochang

    2013-04-01

    Schisandra chinensis, one of the well-known traditional Chinese herbal medicines, is derived from the dry ripe fruits of Schisandra chinensis (Turcz.) Baill. according to the 9th China Pharmacopeia. Lignans are the main components isolated from extracts of S. chinensis and their content varies depending on where S. chinensis was collected. We have established a qualitative and quantitative method based on the bioactive lignans for control of the quality of S. chinensis from different sources. To develop a high-performance liquid chromatography method, an Elite ODS C18 column (250 mm Χ 4.6 mm, 5μm) at a column temperature of 30°C and flow rate of 1.0ml/min using acetonitrile (A) and water (B) as the mobile phase with a linear gradient and the peaks were monitored at 217 nm. All calibration curves showed good linearity (r ≥ 0.9995) within test ranges. This method showed good repeatability for the quantification of these eleven components in S. chinensis with intra- and inter-day relative standard deviations less than 0.43% and 1.21%, respectively. In the recovery test, results of accuracy ranged from 99.51% to 101.31% with RSD values less than 2. The validated method can be successfully applied to quantify the eleven investigated components in 22 samples of S. chinensis from different sources.

  16. High perfomance liquid chromatography fingerprint analysis for quality control of brotowali (Tinospora crispa)

    Science.gov (United States)

    Syarifah, V. B.; Rafi, M.; Wahyuni, W. T.

    2017-05-01

    Brotowali (Tinospora crispa) is widely used in Indonesia as ingredient of herbal medicine formulation. To ensure the quality, safety, and efficacy of herbal medicine products, its chemical constituents should be continuously evaluated. High performance liquid chromatography (HPLC) fingerprint is one of powerful technique for this quality control process. In this study, HPLC fingerprint analysis method was developed for quality control of brotowali. HPLC analysis was performed in C18 column and detection was performed using photodiode array detector. The optimum mobile phase for brotowali fingerprint was acetonitrile (ACN) and 0.1% formic acid in gradient elution mode at a flow rate of 1 mL/min. The number of peaks detected in HPLC fingerprint of brotowali was 32 peaks and 23 peaks for stems and leaves, respectively. Berberine as marker compound was detected at retention time of 20.525 minutes. Evaluation of analytical performance including precision, reproducibility, and stability prove that this HPLC fingerprint analysis was reliable and could be applied for quality control of brotowali.

  17. Simultaneous characterization and quantification of 17 main compounds in Rabdosia rubescens by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Sen Guo

    2017-04-01

    Full Text Available Rabdosia rubescens is a healthy herbal tea and well-known Chinese medicinal herb. To evaluate the quality of R. rubescens from China, a high performance liquid chromatography method with dual-wavelength detection was developed and validated. The method was successfully applied for the simultaneous characterization and quantification of 17 main constituents from four different cultivation regions in China. Under optimal conditions, analysis was performed on a Luna C-18 column and gradient elution with a solvent system of acetonitrile and 0.5% (v/v acetic acid–water at a flow rate of 1.0 mL/min and wavelength of 220 nm and 280 nm. All standard calibration curves exhibited good linearity (r2 > 0.9992 within the test ranges. The precision was evaluated by intraday and interday tests, which revealed relative standard deviation values within the ranges of 0.57–2.35% and 0.52–3.40%, respectively. The recoveries were in the range of 96.37–101.66%. The relative standard deviation values for stability and repeatability were < 5%. The contents of some compounds were low and varied with different cultivars. The proposed method could serve as a prerequisite for quality control of R. rubescens materials and products.

  18. Characterisation of brewpub beer carbohydrates using high performance anion exchange chromatography coupled with pulsed amperometric detection.

    Science.gov (United States)

    Arfelli, Giuseppe; Sartini, Elisa

    2014-01-01

    High performance anion exchange chromatography (HPAEC) coupled with pulsed amperometric detection (PAD) was optimised in order to quantify mannose, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose and maltoheptaose content of beer. The method allows the determination of above mentioned oligosaccharides, in a single chromatographic run, without any pre-treatment. Limit of detection and limit of quantification were suitable for beer. Accuracy and repeatability were good for the entire amount considered. Once optimised HPAEC PAD for the specific matrix, the second goal of this research was to verify the possibility to discriminate beers, depending on their style. The carbohydrates content of brewpub commercial beers was very variable, ranging from 19.3 to 1469mg/L (mannose), 34.5 to 2882mg/L (maltose), 141.9 to 20731mg/L (maltotriose), 168.5 to 7650mg/L (maltotetraose), 20.1 to 2537mg/L (maltopentaose), 22.9 to 3295mg/L (maltohexaose), 8.5 to 2492mg/L (maltoeptaose), even in the same style of beer. However, the carbohydrates content was useful, jointed with other compounds amount, to discriminate different styles of beer. As a matter of fact, principal component analysis put in evidence beer differences considering some fermentation conditions and colour. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Determination of Capsaicin and Dihydrocapsaicin in Capsicum Fruit Samples using High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Ayman Abdel Ghafar

    2011-10-01

    Full Text Available The aim of the present study was to determine the content of capsaicin and dihydrocapsaicin in Capsicum samples collected from city markets in Riyadh (Saudi Arabia, calculate their pungency in Scoville heat units (SHU and evaluate the average daily intake of capsaicin for the population of Riyadh. The investigated samples consisted of hot chillies, red chillies, green chillies, green peppers, red peppers and yellow peppers. Extraction of capsaicinoids was done using ethanol as solvent, while high performance liquid chromatography (HPLC was used for separation, identification and quantitation of the components. The limit of detection (LOD of the method was 0.09 and 0.10 µg/g for capsaicin and dihydrocapsaicin, respectively, while the limit of quantification (LOQ was 0.30 and 0.36 µg/g for capsaicin and dihydrocapsaicin, respectively. Hot chillies showed the highest concentration of capsaicin (4249.0 ± 190.3 µg/g and the highest pungency level (67984.60 SHU, whereas green peppers had the lowest detected concentration (1.0 ± 0.9 µg/g; green peppers, red peppers and yellow peppers were non pungent. The mean consumption of peppers for Riyadh city population was determined to be 15.5 g/person/day while the daily capsaicin intake was 7.584 mg/person/day.

  20. Monosodium glutamate in chicken and beef stock cubes using high-performance liquid chromatography.

    Science.gov (United States)

    Demirhan, Buket Er; Demirhan, Burak; Sönmez, Ceren; Torul, Hilal; Tamer, Uğur; Yentür, Gülderen

    2015-01-01

    In this survey monosodium glutamate (MSG) levels in chicken and beef stock cube samples were determined. A total number of 122 stock cube samples (from brands A, B, C, D) were collected from local markets in Ankara, Turkey. High-performance liquid chromatography with diode array detection (HPLC-DAD) was used for quantitative MSG determination. Mean MSG levels (±SE) in samples of A, B, C and D brands were 14.6 ± 0.2 g kg⁻¹, 11.9 ± 0.3 g kg⁻¹, 9.7 ± 0.1 g kg⁻¹ and 7.2 ± 0.1 g kg⁻¹, respectively. Differences between mean levels of brands were significant. Also, mean levels of chicken stock cube samples were lower than in beef stock cubes. Maximum limits for MSG in stock cubes are not specified in the Turkish Food Codex (TFC). Generally the limit for MSG in foods (except some foods) is established as 10 g kg⁻¹ (individually or in combination).

  1. [Determination of sucralose in foods and beverages by ultraviolet derivatization-high performance liquid chromatography].

    Science.gov (United States)

    Chen, Lu-Ying; Liu, Ya-Pan; Ran, Xue-Qin; Sun, Cheng-Jun

    2014-09-01

    To establish a method for determination of sucralose in foods and beverages using high performance liquid chromatography. Sucralose was extracted with water and centrifuged, and then derivatized with benzoyl chloride in alkaline medium. The ultraviolet absorbing derivatives were separated on a Hydro-RP 80 angstroms C18 column (250 mm x 4.6 mm, 4 microm, Synergi) using methanol-water (95:5,V/V) as mobile phase with UV detection at 232 nm. A good correlation (correlation coefficient=0. 999 8) between detected and actual sucralose was achieved in the range of 0.05 to 1.00 microg. The detection limit of sucralose was 0.00125 microg. The recoveries were in the range from 97.4% to 102.0% with relative standard deviations of less than 5.0%. The intraday and interday relative standard deviations of the method were 1.52% and 4.04%, respectively. This method is simple, rapid, and accurate without the need of special detectors, and it can be used for rapid determination of sucralose in foods and beverages.

  2. A stability-indicating high performance liquid chromatography method to determine apocynin in nanoparticles

    Directory of Open Access Journals (Sweden)

    Juliana Kovalczuk de Oliveira

    2017-04-01

    Full Text Available In this study, we developed and validated a fast, specific, sensitive, precise and stability-indicating high performance liquid chromatography (HPLC method to determine the drug apocynin in bovine serum albumin (BSA nanoparticles. Chromatographic analyses were performed on an RP C18 column and using a photodiode array detector at a wavelength of 276 nm. Mobile phase consisted of a mixture of acetonitrile and 1% acetic acid (60:40, v/v, and it was eluted isocratically at a flow rate of 0.8 mL/min. The retention time of apocynin chromatographic peak was 1.65 min. The method was linear, precise, accurate and specific in the range of 5–100 μg/mL. The intra- and inter-day precisions presented relative standard deviation (RSD values lower than 2%. The method was robust regarding changes in mobile phase proportion, but not for flow rate. Limits of detection and quantitation were 78 ng/mL and 238 ng/mL, respectively. Apocynin was exposed to acid and alkali hydrolysis, oxidation and visible light. The drug suffered mild degradation under acid and oxidation conditions and great degradation under alkali conditions. Light exposure did not degrade the drug. The method was successfully applied to determine the encapsulation efficiency of apocynin in BSA nanoparticles.

  3. [Simultaneous determination of 38 limited colorants in cosmetics by high performance liquid chromatography].

    Science.gov (United States)

    Mao, Xiqin; Li, Chunling; Ren, Guojie; Zhang, Guocui; Li, Xiaofei; Li, Peng

    2015-03-01

    A method has been established for the simultaneous determination of 38 limited colorants in cosmetics by high performance liquid chromatography (HPLC). The samples were extracted by ultrasonic with tetrahydrofuran, methanol, ammonium acetate solution as extraction solvents. After centrifugation, nitrogen blow and redissolved in turn, the extracts were separated on an Agilent zorbax SB-Aq column (150 mm x 3.0 mm, 3.5 µm) using a gradient elution program with acetonitrile and 30 mmol/L ammonium acetate containing 0.075% (v/v) formic acid as mobile phases. The detection wavelengths were set at 254, 416, 484, 514, 590 and 620 nm. The linear ranges of the 38 target compounds were all in the range of 1 to 10 mg/L with correlation coefficients more than 0.999. The limits of quantification (LOQs) for the 38 colorants were in the range of 5-50 µg/g. The average recoveries at two spiked levels ranged from 93.2% to 107.6% with the relative standard deviations (RSDs) less than 10% (n = 6). This method is accurate, simple, sensitive and reliable, and can be used for the analysis of the 38 limited colorants in cosmetics.

  4. Detection of heterogeneous drug-protein binding by frontal analysis and high-performance affinity chromatography.

    Science.gov (United States)

    Tong, Zenghan; Joseph, K S; Hage, David S

    2011-12-09

    This study examined the use of frontal analysis and high-performance affinity chromatography for detecting heterogeneous binding in biomolecular interactions, using the binding of acetohexamide with human serum albumin (HSA) as a model. It was found through the use of this model system and chromatographic theory that double-reciprocal plots could be used more easily than traditional isotherms for the initial detection of binding site heterogeneity. The deviations from linearity that were seen in double-reciprocal plots as a result of heterogeneity were a function of the analyte concentration, the relative affinities of the binding sites in the system and the amount of each type of site that was present. The size of these deviations was determined and compared under various conditions. Plots were also generated to show what experimental conditions would be needed to observe these deviations for general heterogeneous systems or for cases in which some preliminary information was available on the extent of binding heterogeneity. The methods developed in this work for the detection of binding heterogeneity are not limited to drug interactions with HSA but could be applied to other types of drug-protein binding or to additional biological systems with heterogeneous binding. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. High-Performance Affinity Chromatography: Applications in Drug-Protein Binding Studies and Personalized Medicine.

    Science.gov (United States)

    Li, Zhao; Beeram, Sandya R; Bi, Cong; Suresh, D; Zheng, Xiwei; Hage, David S

    2016-01-01

    The binding of drugs with proteins and other agents in serum is of interest in personalized medicine because this process can affect the dosage and action of drugs. The extent of this binding may also vary with a given disease state. These interactions may involve serum proteins, such as human serum albumin or α1-acid glycoprotein, or other agents, such as lipoproteins. High-performance affinity chromatography (HPAC) is a tool that has received increasing interest as a means for studying these interactions. This review discusses the general principles of HPAC and the various approaches that have been used in this technique to examine drug-protein binding and in work related to personalized medicine. These approaches include frontal analysis and zonal elution, as well as peak decay analysis, ultrafast affinity extraction, and chromatographic immunoassays. The operation of each method is described and examples of applications for these techniques are provided. The type of information that can be obtained by these methods is also discussed, as related to the analysis of drug-protein binding and the study of clinical or pharmaceutical samples. © 2016 Elsevier Inc. All rights reserved.

  6. High-throughput analysis of lectin-oligosaccharide interactions by automated frontal affinity chromatography.

    Science.gov (United States)

    Nakamura-Tsuruta, Sachiko; Uchiyama, Noboru; Hirabayashi, Jun

    2006-01-01

    Frontal affinity chromatography (FAC) is a quantitative method that enables sensitive and reproducible measurements of interactions between lectins and oligosaccharides. The method is suitable even for the measurement of low-affinity interactions and is based on a simple procedure and a clear principle. To achieve high-throughput and efficient analysis, an automated FAC system was developed. The system designated FAC-1 consists of two isocratic pumps, an autosampler, and a couple of miniature columns (bed volume, 31.4 microl) connected in parallel to either a fluorescence or an ultraviolet detector. By use of this parallel-column system, the time required for each analysis was reduced substantially. Under the established conditions, fewer than 10 hrs are required for 100 interaction analyses, consuming as little as 1 pmol pyridylaminated oligosaccharide for each analysis. This strategy for FAC should contribute to the construction of a lectin-oligosaccharide interaction database essential for future glycomics. Overall features and practical protocols for interaction analyses using FAC-1 are described.

  7. Determination of glyphosate in soil/sludge by high performance liquid chromatography.

    Science.gov (United States)

    Sun, Lisi; Kong, Deyang; Gu, Weidong; Guo, Xinyan; Tao, Wenqi; Shan, Zhengjun; Wang, Ying; Wang, Na

    2017-06-16

    In order to evaluate the pollution caused due to glyphosate (Glyp) in soils and sludge, it is important to establish a set of standard determination techniques. In this work, the previously reported HPLC analytical method for determination of Glyp has been improved in order to be applied for all kinds of soils/sludge. The soil/sludge samples were extracted using sodium phosphate and trisodium citrate aqueous solutions. The extract was adjusted to pH 9 and contaminations were removed by washing with n-hexane. The method developed in this work further involves derivatization with 9-fluorenylmethylchloroformate (FMOC-Cl) followed by high performance liquid chromatography (HPLC) coupled with fluorescence detection. The method was validated in three soil (red soil, black soil and paddy soil) and two sludge samples (lake and river sludge) from China and verified in six laboratories. A good linear relationship (correlation coefficients ≥0.999) was observed within the range of 0.005-0.5mg/L. The limit of detection (LOD) and the limit of quantitation (LOQ) were determined to be 0.01mg/kg and 0.04mg/kg, respectively. The precision and accuracy were satisfactory with the relative standard deviation (RSD) lower than 15% and the mean recovery values ranging from 75% to 110% (n=6), that spiked at three levels (0.1, 0.5 and 1.0mg/kg). Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Arsenic speciation in soil using high performance liquid chromatography/inductively coupled plasma/mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bass, D.A.; Yaeger, J.S.; Parish, K.J.; Crain, J.S.; Kiely, J.T.; Gowdy, M.J. [Argonne National Lab., IL (United States); Mohrman, G.B.; Besmer, M.G. [Rocky Mountain Arsenal, Commerce City, CO (United States)

    1996-08-01

    A method has been developed to identify and quantify As(III), As(V), and organoarsenic compounds in soil samples from the Rocky Mountain Arsenal (RMA) by high performance liquid chromatography/inductively coupled plasma/mass spectrometry (HPLC/ICP/MS). The soils were extracted using tetrabutylammonium hydroxide (TBAH) and sonication. The percentages of As(III), As(V), and organoarsenic species extracted from soil samples were 30, 50, and 100 respectively. The arsenic species were not altered during the extraction process. They were separated by reversed-phase, ion-pairing, HPLC using a microbore Inertsil-ODS{trademark} column. The HPLC column effluent was introduced into an ICP/MS system using a direct injection nebulizer (DIN). Detection limits of less than 1 pg were readily obtained for each arsenic species. Internal standards are recommended to increase accuracy and precision. Soil samples spiked with arsenic oxide, sodium arsenate, dimethylarsinic acid (DMAA), and chlorovinyl arsenious acid (CVAA) were extracted, identified and quantified with the HPLC/ICP/MS system. The soil samples were analyzed in support of the analytical needs of a thermal desorption treatability study being conducted at the RMA.

  9. Determination of saccharin in pharmaceuticals by high performance thin layer chromatography

    Directory of Open Access Journals (Sweden)

    MIRA CAKAR

    2006-06-01

    Full Text Available A simple, accurate and selective high performance thin layer chromatographic method for the determination of saccharin in pharmaceuticals has been developed. The chromatography was performed on silica-gel 60F254 plates with ethyl acetate–carbon tetrachloride–acetic acid (3 + 4 + 0.5 v/v/v as the mobile phase. The chromatographic zones corresponding to the saccharin spots were scanned in the reflectance/absorbance mode at l= 230 mm. For the standard curves, two series of saccharin sodium salt solutions were prepared: in methanol (solvent 1 and in ethyl acetate–acetic acid (9:1, v/v mixture (solvent 2. A linear calibration relationship was observed within the concentration range from 300 – 1200 ng saccharin sodium salt per spot, correlation coefficients being 0.998 (solvent 1 and 0.995 (solvent 2. The relationship between the peak area and the amount of saccharin sodium salt was evaluated by linear regression analysis. The limits of detection and quantification of saccharin sodium salt were 35 ng and 110 ng per spot (solvent 1, respectively, and 45 ng and 150 ng per spot (solvent 2, respectively. Mean recovery values of 103.5 % (solvent 1 and 102.3 % (solvent 2, and RSD values of 4.42 % (solvent 1 and 2.53 % (solvent 2 were obtained. The proposed method was applied for saccharin determination in two pharmaceutical preparations, effervescent tablets and a carbomer-based gel.

  10. Determination of caffeine, theophylline and theobromine in serum and saliva using high-performance liquid chromatography.

    Science.gov (United States)

    Scott, N R; Chakraborty, J; Marks, V

    1984-03-01

    A method is described for the measurement of theobromine, theophylline and caffeine in serum and saliva by high-performance liquid chromatography (HPLC). A chloroform/isopropanol extract (85:15, v/v) is evaporated to dryness and chromatographed on a 100 X 4.5 mm id Hypersil octadecylsilane column with UV detection at 280 nm. Theobromine, theophylline, caffeine and the internal standard proxyphylline are satisfactorily resolved with an elution system of acetonitrile/tetrahydrofuran/50 mM acetate buffer, pH 4.0, (4:1:95, v/v). No interference is observed from the presence of xanthine metabolites or any of a number of common drugs examined. A good correlation was observed between the concentrations of caffeine in serum and in saliva suggesting that salivary measurements may be useful for the study of caffeine pharmacokinetics in man. Caffeine levels determined by the HPLC procedure described here agreed well with those obtained by a radioimmunoassay method. The method is also suitable for determining the xanthine content of beverages by direct injection of diluted samples.

  11. High efficiency polyethylene glycol diacrylate monoliths for reversed-phase capillary liquid chromatography of small molecules.

    Science.gov (United States)

    Aggarwal, Pankaj; Lawson, John S; Tolley, H Dennis; Lee, Milton L

    2014-10-17

    Highly cross-linked monolithic networks (i.e., polyethylene glycol diacrylate, PEGDA) synthesized from monomers containing varying ethylene oxide chain lengths were fabricated inside fused silica capillary columns for use in liquid chromatography (LC) of small molecules. Tergitol was used as a surfactant porogen in combination with other typical organic liquid porogens. Column performance was correlated with quantitative descriptors of the physical/chemical properties of the monomers and porogens using a statistical model. Solubility and viscosity values of the components were identified as important predictors of monolith morphology and efficiency. The chromatographic retention mechanism was determined to be principally reversed-phase (RP) with additional hydrogen bonding between the polar groups of the analytes and the ethylene oxide groups embedded in the monolith structure. The fabricated monolithic columns were evaluated under RPLC conditions using phenols, hydroxy benzoic acids, and alkyl parabens as test compounds. Isocratic elution of hydroxy benzoic acids at a linear velocity of 0.04 cm/s using a PEGDA-700 monolith gave chromatographic peaks with little tailing (i.e., tailing factorphenol standards (3 different columns). Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Determination of betamethasone dipropionate and salicylic acid in pharmaceutical preparations by high-performance liquid chromatography.

    Science.gov (United States)

    Kedor-Hackmann, E R; Gianotto, E A; Santoro, M I

    1998-06-01

    The simultaneous determination of betamethasone dipropionate (BD) and salicylic acid (SA) in both ointment and topical solution was developed using high-performance liquid chromatography (HPLC). The method was standardized using a LiChrospher 100 RP-18 (125 x 4 mm, 5 microns) column, acetonitrile-tetrahydrofuran-acetic acid 1% (25:20:55 v/v), apparent pH 3.3, as mobile phase, and UV detection at 254 nm. The peak area response versus concentration was linear in a concentration range from 5.0 to 50.0 micrograms/ml of BD and from 20.0 to 200.0 micrograms/ml of SA. The correlation coefficients were 0.9997 for BD and 0.9987 for SA, and the relative standard errors of estimates were 1.38% for BD and 3.27% for SA. The coefficient of variation and the recovery average were, respectively, 0.41-1.15% and 100.09% for BD, and 0.57-0.95% and 99.79% for SA.

  13. High performance liquid chromatography method for residues analysis of thidiazuron in apple and soil.

    Science.gov (United States)

    Hu, Ji-Ye; Hu, Ya-Qin; Chen, Yang; Yang, Tao

    2011-10-01

    A rapid, sensitive and reliable analytical method for thidiazuron residues in apple and soil was established. The residual levels of the pesticide in apple and soil were determined by high performance liquid chromatography (HPLC) with UV detector. Samples of apple and soil were extracted with acetonitrile-water solutions, and then cleaned up by Florisil or C(18) cartridges. The results showed good linearity (r(2)=1.000) over the concentration range of 0.01-5.0 mg/L. Limits of quantification (LOQ) of the method were 0.01 mg/kg for both soil and apple. Recovery from the apple and soil samples were 83.36%-84.08% and 85.27%-89.83%, respectively, and the corresponding relative standard deviations (RSDs) of the recovery data were 0.155%-0.524% and 0.475%-4.79% for the three fortified levels (0.01, 0.1, 0.5 mg/kg). The analyte in the samples were further confirmed by electrospray ionization tandem mass spectrometry (ESI-MS/MS). It was demonstrated that the proposed method was simple and efficient, and particularly suitable for detecting thidiazuron residues in apple and soil. © Springer Science+Business Media, LLC 2011

  14. [Determination of phthalic anhydride in ambient air by high performance liquid chromatography].

    Science.gov (United States)

    Zaĭtseva, N V; Ulanova, T S; Karnazhitskaia, T D; Antip'eva, M V; Kislitsina, A V

    2011-01-01

    The paper considers the measurement of phthalic anhydride in the ambient air samples by high performance liquid chromatography. It describes conditions for air sampling and analysis of phthalic anhydride levels in the presence of concomitant components of its production (phthalic and maleic acids, maleic anhydride, etc.) on a liquid chromatograph with an UV detector. The procedure was tested, by estimating the quality of ambient air at the border of a sanitary protection zone of phthalic anhydride production and when analyzing the air in the industrial area. Field studies detected the concentrations of phthalic anhydrate in the air of an enterprise area, which were equal to 0.017-0.115 mg/dm3. Phthalic anhydride was detectable at a concentration of 0.001-0.0021 mg/dm3 at the border of the existing sanitary protection zone in single cases. The procedure has been recommended to measure the mass concentrations of phthalic anhydride aerosol and vapors in ambient air at the reference concentration.

  15. A universal, high recovery assay for protein quantitation through temperature programmed liquid chromatography (TPLC).

    Science.gov (United States)

    Orton, Dennis J; Doucette, Alan A

    2013-03-15

    As an alternative to direct UV absorbance measurements, estimation of total protein concentration is typically conducted through colorimetric reagent assays. However, for protein-limited applications, the proportion of the sample sacrificed to the assay becomes increasingly significant. This work demonstrates a method for quantitation of protein samples with high recovery. Temperature programmed liquid chromatography (TPLC) with absorbance detection at 214nm permits accurate estimation of total protein concentration from samples containing as little as 0.75μg. The method incorporates a temperature gradient from 25 to 80°C to facilitate elution of total protein into a single fraction. Analyte recovery, as measured from 1 and 10μg protein extracts of Escherichia coli, is shown to exceed 93%. Extinction coefficients at 214nm were calculated across the human proteome, providing a relative standard deviation of 21% (versus 42% at 280nm), suggesting absorbance values at 214nm provide a more consistent measure of protein concentration. These results translate to a universal protein detection strategy exhibiting a coefficient of variation below 10%. Together with the sensitivity and tolerance to contaminants, TPLC with UV detection is a favorable alternative to colorimetric assay for total protein quantitation, particularly in sample-limited applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Simultaneous determination of caffeine, theobromine, and theophylline by high-performance liquid chromatography.

    Science.gov (United States)

    Bispo, Marcia S; Veloso, Márcia Cristina C; Pinheiro, Heloísa Lúcia C; De Oliveira, Rodolfo F S; Reis, José Oscar N; De Andrade, Jailson B

    2002-01-01

    This work relates the development of an analytical methodology to simultaneously determine three methylxanthines (caffeine, theobromine, and theophylline) in beverages and urine samples based on reversed-phase high-performance liquid chromatography. Separation is made with a Bondesil C18 column using methanol-water-acetic acid or ethanol-water-acetic acid (20:75:5, v/v/v) as the mobile phase at 0.7 mL/min. Identification is made by absorbance detection at 273 nm. Under optimized conditions, the detection limit of the HPLC method is 0.1 pg/mL for all three methylxanthines. This method is applied to urine and to 25 different beverage samples, which included coffee, tea, chocolate, and coconut water. The concentration ranges determined in the beverages and urine are: theobromine; < 0.1 pg/mL to 47 microg/mL and < 0.1 pg/mL to 66.3 microg/mL for theophylline. The method proposed in this study is rapid and suitable for the simultaneous quantitation of methylxanthines in beverages and human urine samples and requires no extraction step or derivatization.

  17. High performance liquid chromatography determination of theobromine and caffeine in cocoa beans gamma irradiated

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Anderson D.B. [Faculdade de Engenharia de Varginha, MG (Brazil); Mansur Neto, Elias [Minas Gerais Univ., Belo Horizonte, MG (Brazil)

    1997-12-01

    Irradiation is a processing technology that has been shown to be a wholesome process by many scientific studies conducted worldwide during the past 40 years, which has been approved by 37 countries. Irradiated foods have been studied so extensively, that the effects on foods are better understood than any other preservation process, including food freezing and dehydration. Cocoa beans has been commercially irradiated in countries such as Ivory Coast and Argentina. The alkaloids theobromine and caffeine are responsible for the mildly stimulating properties and bitter taste of cocoa and chocolate products. Previously fermented dried and nonfumigated cocoa beans were irradiated at doses of 0, 5.0, 10.0 and 20.0 kGy using Co-60 gamma rays. The samples were analysed for determining theobromine and caffeine contents in the cocoa beans by TIMBIE et al. (1978) high performance liquid chromatography (HPLC) method. Boiling water extracts were cooled, centrifuged and injected into the chromatograph. Theobromine and caffeine were quantitated at 273 nm and showed the tendency of decreasing as the dose of radiation increases. Theobromine and caffeine ranged from 42.3 to 37.1 mg/g and from 7.60 to 6.13 mg/g. respectively from 0 to 20.0 kGy. These results were discussed in relation to the possible acceptance of radiosterization of cocoa beans commercially up to the dose of 20.0 kGy. (author). 10 refs., 1 tab.

  18. Simultaneous characterization and quantification of 17 main compounds in Rabdosia rubescens by high performance liquid chromatography.

    Science.gov (United States)

    Guo, Sen; Cui, Xueqin; Jiang, Mi; Bai, Lu; Tian, Xiao; Guo, Tiantian; Liu, Qingchao; Zhang, Li; Ho, Chi-Tang; Bai, Naisheng

    2017-04-01

    Rabdosia rubescens is a healthy herbal tea and well-known Chinese medicinal herb. To evaluate the quality of R. rubescens from China, a high performance liquid chromatography method with dual-wavelength detection was developed and validated. The method was successfully applied for the simultaneous characterization and quantification of 17 main constituents from four different cultivation regions in China. Under optimal conditions, analysis was performed on a Luna C-18 column and gradient elution with a solvent system of acetonitrile and 0.5% (v/v) acetic acid-water at a flow rate of 1.0 mL/min and wavelength of 220 nm and 280 nm. All standard calibration curves exhibited good linearity (r 2  > 0.9992) within the test ranges. The precision was evaluated by intraday and interday tests, which revealed relative standard deviation values within the ranges of 0.57-2.35% and 0.52-3.40%, respectively. The recoveries were in the range of 96.37-101.66%. The relative standard deviation values for stability and repeatability were < 5%. The contents of some compounds were low and varied with different cultivars. The proposed method could serve as a prerequisite for quality control of R. rubescens materials and products. Copyright © 2016. Published by Elsevier B.V.

  19. High-throughput protein precipitation and hydrophobic interaction chromatography: salt effects and thermodynamic interrelation.

    Science.gov (United States)

    Nfor, Beckley K; Hylkema, Nienke N; Wiedhaup, Koenraad R; Verhaert, Peter D E M; van der Wielen, Luuk A M; Ottens, Marcel

    2011-12-09

    Salt-induced protein precipitation and hydrophobic interaction chromatography (HIC) are two widely used methods for protein purification. In this study, salt effects in protein precipitation and HIC were investigated for a broad combination of proteins, salts and HIC resins. Interrelation between the critical thermodynamic salting out parameters in both techniques was equally investigated. Protein precipitation data were obtained by a high-throughput technique employing 96-well microtitre plates and robotic liquid handling technology. For the same protein-salt combinations, isocratic HIC experiments were performed using two or three different commercially available stationary phases-Phenyl Sepharose low sub, Butyl Sepharose and Resource Phenyl. In general, similar salt effects and deviations from the lyotropic series were observed in both separation methods, for example, the reverse Hofmeister effect reported for lysozyme below its isoelectric point and at low salt concentrations. The salting out constant could be expressed in terms of the preferential interaction parameter in protein precipitation, showing that the former is, in effect, the net result of preferential interaction of a protein with water molecules and salt ions in its vicinity. However, no general quantitative interrelation was found between salting out parameters or the number of released water molecules in protein precipitation and HIC. In other words, protein solubility and HIC retention factor could not be quantitatively interrelated, although for some proteins, regular trends were observed across the different resins and salt types. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Sources of Variability in Chlorophyll Analysis by Fluorometry and by High Performance Liquid Chromatography. Chapter 22

    Science.gov (United States)

    VanHeukelem, Laurie; Thomas, Crystal S.; Glibert, Patricia M.

    2001-01-01

    The need for accurate determination of chlorophyll a (chl a) is of interest for numerous reasons. From the need for ground-truth data for remote sensing to pigment detection for laboratory experimentation, it is essential to know the accuracy of the analyses and the factors potentially contributing to variability and error. Numerous methods and instrument techniques are currently employed in the analyses of chl a. These methods range from spectrophotometric quantification, to fluorometric analysis and determination by high performance liquid chromatography. Even within the application of HPLC techniques, methods vary. Here we provide the results of a comparison among methods and provide some guidance for improving the accuracy of these analyses. These results are based on a round-robin conducted among numerous investigators, including several in the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) and HyCODE Programs. Our purpose here is not to present the full results of the laboratory intercalibration; those results will be presented elsewhere. Rather, here we highlight some of the major factors that may contribute to the variability observed. Specifically, we aim to assess the comparability of chl a analyses performed by fluorometry and HPLC, and we identify several factors in the analyses which may contribute disproportionately to this variability.

  1. Resolution of triacylglycerol positional isomers by reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Momchilova, Svetlana; Tsuji, Koichiro; Itabashi, Yutaka; Nikolova-Damyanova, Boryana; Kuksis, Arnis

    2004-08-01

    The ability of reversed-phase high-performance liquid chromatography (RP-HPLC) to separate some positionally isomeric disaturated and monounsaturated triacylglycerols (TAGs) as intact species is demonstrated for the first time. Mobile phases of acetonitrile modified with methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, acetone, or dichloromethane were tested for the separation of POP-PPO, PLP-PPL, PEP-PPE, and PDP-PPD (P-palmitic, O-oleic, L-linoleic, E-eicosapentaenoic, D-docosahexaenoic acid residue) on a single RP-HPLC column. The resolution improved with increasing number of double bonds in the acyl residues. While POP and PPO were only partially resolved, PDP and PPD were fully separated with all tested mobile phases, except those containing methanol. Also separated were the four TAGs having the same equivalent carbon number (ECN = 42), PEP, PPE, PDP, and PPD, on a single RP-HPLC column with mobile phase acetonitrile-2-propanol (70:30, v/v) at 0.8 mL/min. In all cases the isomer with the unsaturated acyl residue in either 1- or 3-position was retained more strongly than the respective 2-isomer.

  2. Determination of metformin in human plasma by high-performance liquid chromatography.

    Science.gov (United States)

    Amini, Hossein; Ahmadiani, Abolhassan; Gazerani, Parisa

    2005-09-25

    A simple, selective and sensitive high-performance liquid chromatographic method with spectrophotometric detection was developed for the determination of antihyperglycemic agent metformin in human plasma using a novel sample extraction procedure. Liquid-liquid extraction of metformin and ranitidine (as internal standard) from plasma samples was performed with 1-butanol/n-hexane (50:50, v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using a silica column (250 mmx4.6 mm, 5 microm) under isocratic elution with acetonitrile-40 mM aqueous sodium dihydrogen phosphate (25:75, v/v), pH 6. The limit of quantification (LOQ) was 15.6 ng/ml and the calibration curves were linear up to 2000 ng/ml. The mean absolute recoveries for metformin and internal standard using the present extraction procedure were 98 and 95%, respectively. The intra- and inter-day coefficient of variation and percent error values of the assay method were all less than 8.3%.

  3. Sensitive determination of clarithromycin in human plasma by high-performance liquid chromatography with spectrophotometric detection.

    Science.gov (United States)

    Amini, Hossein; Ahmadiani, Abolhassan

    2005-03-25

    A rapid, selective and sensitive high-performance liquid chromatographic method with spectrophotometric detection was developed for the determination of clarithromycin in human plasma. Liquid-liquid extraction of clarithromycin and norverapamil (as internal standard) from plasma samples was performed with n-hexane/1-butanol (98:2, v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using a CN column (250 mm x 4.6 mm, 5 microm) under isocratic elution with acetonitrile-50 mM aqueous sodium dihydrogen phosphate (32:68, v/v), pH 4.5. Detection was made at 205 nm and analyses were run at a flow-rate of 1.0 ml/min at 40 degrees C. The analysis time was less than 11 min. The method was specific and sensitive with a quantification limit of 31.25 ng/ml and a detection limit of 10 ng/ml in plasma. The mean absolute recovery of clarithromycin from plasma was 95.9%, while the intra- and inter-day coefficient of variation and percent error values of the assay method were all less than 9.5%. Linearity was assessed in the range of 31.25-2000 ng/ml in plasma with a correlation coefficient of greater than 0.999. The method was used to analyze several hundred human plasma samples for bioavailability studies.

  4. [Application of denaturing high performance liquid chromatography for detection of alpha-hemoglobin-stabilizing protein gene].

    Science.gov (United States)

    Wang, Zhipeng

    2011-04-01

    An assay method for alpha-hemoglobin-stabilizing protein (AHSP) gene was established based on denaturing high performance liquid chromatography (DHPLC). The AHSP gene sequences are divided into six fragments. Because of one or two common single nucleotide polymorphism (SNPs) in the first, second, fourth and sixth fragments, all samples should be analyzed individually when the fragments were detected. The third and fifth fragments were detected by DHPLC technique combined with DNA pooling for no common SNP in the fragments. The six common SNPs in AHSP gene can be genotyped accurately by the established method. After analyzing AHSP gene of 40 samples by DHPLC detection and gene sequencing, it was found that the results of the two methods were completely consistent. After AHSP gene of 365 samples being analyzed by DHPLC, two rare SNPs (11,810 G > A and 12,802 C > T)were found. Two missense mutations (AHSP D29V and AHSP V56G) were also found. AHSP D29V mutation is a novel mutation. AHSP V56G is a rare mutation. It demonstrated that this method is suitable for the detection of alpha-hemoglobin-stabilizing protein gene.

  5. Simple ultraviolet and high-performance liquid chromatography methods for the evaluation of sunscreen efficacy.

    Science.gov (United States)

    Maw, Khin Lay; Caton-Williams, Julianne; Salon, Jozef; Huang, Zhen

    2011-08-01

    To prevent DNA damage caused by the ultraviolet (UV) radiation of sunlight, sunscreens are commonly used to protect human skin. Current analysis of sunscreens' effectiveness is done through complicated procedures, including human exposure. We sought to design a simple system using thymidine-thymidine (TT) dinucleotides to analyze the effectiveness of sunscreens. We can directly analyze sunscreen effectiveness and the formation of TT photolesions simply by using UV spectrophotometry and high-performance liquid chromatography (HPLC). Efficient sunscreen has protective effects against UV irradiation damage. We have developed a simple method using TT dinucleotide, UV, and HPLC for the analysis of sunscreen effectiveness. Our research indicates that the analytical results from UV are consistent with those of HPLC, which is used to monitor the formation of the TT photolesions. Moreover, both UV and HPLC analyses indicate that TT dinucleotides are better protected against UV damage, using the sunscreens with higher UVB sun protection factor (SPF) value, and that sunscreens with higher SPF lead to reduced photolesion formation. Our UV and HPLC analyses confirm the SPF grading of commercial sunscreens. In this experiment, only sunscreens were tested. The experiment, therefore, does not apply to other commercial products, such as cosmetic materials that claim UV protection as a secondary benefit. In conclusion, we have established a simple strategy to analyze the effectiveness of sunscreens and the quality of these potential cancer-preventive products. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  6. Molecular monitoring of the intestinal flora by denaturing high performance liquid chromatography.

    Science.gov (United States)

    Goldenberg, Oliver; Herrmann, Stefanie; Marjoram, Gina; Noyer-Weidner, Mario; Hong, George; Bereswill, Stefan; Göbel, Ulf B

    2007-01-01

    Gut flora analysis is hampered by the complexity of the intestinal microbiota and by inherent limitations of culture-based approaches. Therefore, culture-independent molecular methods based upon 16S rRNA gene analysis were applied successfully for the analysis of complex microbial communities. However, generally accepted and validated profiling methods such as denaturing and temperature gradient gel electrophoresis (DGGE/TGGE) are still laborious and time consuming. Thus, we adapted the separation of amplified bacterial 16S rRNA gene fragments by denaturing high performance liquid chromatography (DHPLC) using the WAVE Microbial Analysis System as a rapid and convenient means to display complex intestinal bacterial communities and to monitor changes in the gut flora. The separation of 16S rRNA gene fragments amplified from reference strains representing main gut bacterial populations and from human stool samples revealed that DHPLC analysis effectively detects bacterial groups predominant in the human gut flora. The investigation of faecal samples from hospitalized patients before, during and after antibiotic therapy showed that PCR-based DHPLC can be used to monitor gut flora changes. Results from DHPLC analysis were comparable with DGGE profiles generated from the same samples, demonstrating that the adapted DHPLC protocol is well suited for the analysis of complex microbial communities.

  7. High catechin concentrations detected in Withania somnifera (ashwagandha by high performance liquid chromatography analysis

    Directory of Open Access Journals (Sweden)

    Sulaiman Siti

    2011-08-01

    Full Text Available Abstract Background Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt. Methods WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods. Results High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%. Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g. Conclusion The results indicating that W. somnifera is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of W. somnifera such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties.

  8. High catechin concentrations detected in Withania somnifera (ashwagandha) by high performance liquid chromatography analysis.

    Science.gov (United States)

    Alam, Nadia; Hossain, Monzur; Khalil, Md Ibrahim; Moniruzzaman, Mohammed; Sulaiman, Siti Amrah; Gan, Siew Hua

    2011-08-19

    Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt). WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods. High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight) and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%). Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin) have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g). The results indicating that W. somnifera is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of W. somnifera such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties.

  9. Evaluation of injection methods for fast, high peak capacity separations with low thermal mass gas chromatography.

    Science.gov (United States)

    Fitz, Brian D; Mannion, Brandyn C; To, Khang; Hoac, Trinh; Synovec, Robert E

    2015-05-01

    Low thermal mass gas chromatography (LTM-GC) was evaluated for rapid, high peak capacity separations with three injection methods: liquid, headspace solid phase micro-extraction (HS-SPME), and direct vapor. An Agilent LTM equipped with a short microbore capillary column was operated at a column heating rate of 250 °C/min to produce a 60s separation. Two sets of experiments were conducted in parallel to characterize the instrumental platform. First, the three injection methods were performed in conjunction with in-house built high-speed cryo-focusing injection (HSCFI) to cryogenically trap and re-inject the analytes onto the LTM-GC column in a narrower band. Next, the three injection methods were performed natively with LTM-GC. Using HSCFI, the peak capacity of a separation of 50 nl of a 73 component liquid test mixture was 270, which was 23% higher than without HSCFI. Similar peak capacity gains were obtained when using the HSCFI with HS-SPME (25%), and even greater with vapor injection (56%). For the 100 μl vapor sample injected without HSCFI, the preconcentration factor, defined as the ratio of the maximum concentration of the detected analyte peak relative to the analyte concentration injected with the syringe, was determined to be 11 for the earliest eluting peak (most volatile analyte). In contrast, the preconcentration factor for the earliest eluting peak using HSCFI was 103. Therefore, LTM-GC is demonstrated to natively provide in situ analyte trapping, although not to as great an extent as with HSCFI. We also report the use of LTM-GC applied with time-of-flight mass spectrometry (TOFMS) detection for rapid, high peak capacity separations from SPME sampled banana peel headspace. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. A Straightforward Method for Glucosinolate Extraction and Analysis with High-pressure Liquid Chromatography (HPLC).

    Science.gov (United States)

    Grosser, Katharina; van Dam, Nicole M

    2017-03-15

    Glucosinolates are a well-studied and highly diverse class of natural plant compounds. They play important roles in plant resistance, rapeseed oil quality, food flavoring, and human health. The biological activity of glucosinolates is released upon tissue damage, when they are mixed with the enzyme myrosinase. This results in the formation of pungent and toxic breakdown products, such as isothiocyanates and nitriles. Currently, more than 130 structurally different glucosinolates have been identified. The chemical structure of the glucosinolate is an important determinant of the product that is formed, which in turn determines its biological activity. The latter may range from detrimental (e.g., progoitrin) to beneficial (e.g., glucoraphanin). Each glucosinolate-containing plant species has its own specific glucosinolate profile. For this reason, it is important to correctly identify and reliably quantify the different glucosinolates present in brassicaceous leaf, seed, and root crops or, for ecological studies, in their wild relatives. Here, we present a well-validated, targeted, and robust method to analyze glucosinolate profiles in a wide range of plant species and plant organs. Intact glucosinolates are extracted from ground plant materials with a methanol-water mixture at high temperatures to disable myrosinase activity. Thereafter, the resulting extract is brought onto an ion-exchange column for purification. After sulfatase treatment, the desulfoglucosinolates are eluted with water and the eluate is freeze-dried. The residue is taken up in an exact volume of water, which is analyzed by high-pressure liquid chromatography (HPLC) with a photodiode array (PDA) or ultraviolet (UV) detector. Detection and quantification are achieved by conducting comparisons of the retention times and UV spectra of commercial reference standards. The concentrations are calculated based on a sinigrin reference curve and well-established response factors. The advantages and

  11. CHARACTERIZATION OF THE BINDING OF SULFONYLUREA DRUGS TO HSA BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

    Science.gov (United States)

    Joseph, K.S.; Hage, David S.

    2010-01-01

    Sulfonylurea drugs are often prescribed as a treatment for type II diabetes to help lower blood sugar levels by stimulating insulin secretion. These drugs are believed to primarily bind in blood to human serum albumin (HSA). This study used high-performance affinity chromatography (HPAC) to examine the binding of sulfonylureas to HSA. Frontal analysis with an immobilized HSA column was used to determine the association equilibrium constants (Ka) and number of binding sites on HSA for the sulfonylurea drugs acetohexamide and tolbutamide. The results from frontal analysis indicated HSA had a group of relatively high affinity binding regions and weaker binding sites for each drug, with average Ka values of 1.3 (± 0.2) × 105 M−1 and 3.5 (± 3.0) × 102 M−1 for acetohexamide and values of 8.7 (± 0.6) × 104 and 8.1 (± 1.7) × 103 M−1 for tolbutamide. Zonal elution and competition studies with site-specific probes were used to further examine the relatively high affinity interactions of these drugs by looking directly at the interactions that were occurring at Sudlow sites I and II of HSA (i.e., the major drug binding sites on this protein). It was found that acetohexamide was able to bind at both Sudlow sites I and II, with Ka values of 1.3 (± 0.1) × 105 and 4.3 (± 0.3) × 104 M−1, respectively, at 37°C. Tolbutamide also appeared to interact with both Sudlow sites I and II, with Ka values of 5.5 (± 0.2) × 104 and 5.3 (± 0.2) × 104 M−1, respectively. The results provide a more quantitative picture of how these drugs bind with HSA and illustrate how HPAC and related tools can be used to examine relatively complex drug-protein interactions. PMID:20435530

  12. Analysis of the Constituents in “Zhu She Yong Xue Shuan Tong” by Ultra High Performance Liquid Chromatography with Quadrupole Time-of-Flight Mass Spectrometry Combined with Preparative High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Lin-Lin Wang

    2015-11-01

    Full Text Available “Zhu She Yong Xue Shuan Tong” lyophilized powder (ZSYXST, consists of a series of saponins extracted from Panax notoginseng, which has been widely used in China for the treatment of strokes. In this study, an ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS combined with preparative high performance liquid chromatography (PHPLC method was developed to rapidly identify both major and minor saponins in ZSYXST. Some high content components were removed through PHPLC in order to increase the sensitivity of the trace saponins. Then, specific characteristic fragment ions in both positive and negative mode were utilized to determine the types of aglycone, saccharide, as well as the saccharide chain linkages. As a result, 94 saponins, including 20 pairs of isomers and ten new compounds, which could represent higher than 98% components in ZSYXST, were identified or tentatively identified in commercial ZSYXST samples.

  13. A New AutomatedMethod to Analyze Urinary 8-Hydroxydeoxyguanosine by a High-performance Liquid Chromatography-Electrochemical Detector System

    OpenAIRE

    Hiroshi, Kasai; Department of Environmental Oncology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health

    2003-01-01

    A new method was developed to analyze urinary 8-hydroxydeoxyguanosine (8-OH-dG) by high-performance liquid chromatography (HPLC) coupled to an electrochemical detector (ECD). This method is unique because (i) urine is first fractionated by anion exchange chromatography (polystyrene-type resin with quaternary ammonium group, sulfate form) before analysis by reverse phase chromatography; and (ii) the 8-OHdG fraction in the first HPLC is precisely and automatically collected based on the added r...

  14. High performance thin layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) for the qualitative and quantitative analysis of Calendula officinalis-advantages and limitations.

    Science.gov (United States)

    Loescher, Christine M; Morton, David W; Razic, Slavica; Agatonovic-Kustrin, Snezana

    2014-09-01

    Chromatography techniques such as HPTLC and HPLC are commonly used to produce a chemical fingerprint of a plant to allow identification and quantify the main constituents within the plant. The aims of this study were to compare HPTLC and HPLC, for qualitative and quantitative analysis of the major constituents of Calendula officinalis and to investigate the effect of different extraction techniques on the C. officinalis extract composition from different parts of the plant. The results found HPTLC to be effective for qualitative analysis, however, HPLC was found to be more accurate for quantitative analysis. A combination of the two methods may be useful in a quality control setting as it would allow rapid qualitative analysis of herbal material while maintaining accurate quantification of extract composition. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Combined fibroblast growth factor receptor 4 cell membrane chromatography online with high performance liquid chromatography/mass spectrometry to screen active compounds in Brassica albla.

    Science.gov (United States)

    Zhang, Tao; Han, Shengli; Huang, Jing; Wang, Sicen

    2013-01-01

    We investigated an analytical method for the recognition separation, and identification of active components from the traditional Chinese medicinal plant Brassica albla L. using fibroblast growth factor receptor 4 cell membrane chromatography (FGFR4/CMC) with high performance liquid chromatography/mass spectrometry (HPLC/MS). HEK293-FGFR4 cells were obtained by stable transfection of the HEK293 cell line with pcDNA3.1 vector containing the FGFR4 gene. Crude extracts of B. albla L. were firstly subjected to FGFR4/CMC column, and the retain contents on the FGFR4/CMC column were then transferred and enriched using a pre-column, and a ten port column switcher were used between FGFR4/CMC column and HPLC. The retained components on FGFR4/CMC column were then directly delivered to the HPLC/MS system for separation and identification. Gefitinib, nicotine, atenolol, and nimodipine were used in order to verify FGFR4/CMC-HPLC/MS system specificity. Subsequently, we investigated the reproducibility and reliability of the FGFR4/CMC-HPLC/MS system. Finally, sinapine was identified as an active component of B. albla L. The MTT colorimetric assay revealed sinapine could inhibit the proliferation of HEK293-FGFR4 cells with dose dependence. Competitive displacement assay approved getitinib could occupy binding site of sinapine with competition way. And FleX dock simulation further exhibited sinapine and gefitinib could bind with the FGFR4 tyrosine active domain. Thus, sinapine is a potential tumor antagonist that acts on the tyrosine kinase domain. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. High-performance liquid chromatography of water-soluble choline metabolites.

    Science.gov (United States)

    Liscovitch, M; Freese, A; Blusztajn, J K; Wurtman, R J

    1985-11-15

    We have developed a new method for the separation of [3H]choline metabolites by high-performance liquid chromatography. Using this method it is possible to separate, in one step, all of the known major water-soluble choline metabolites present in crude acid extracts of cells that have been incubated with [3H]choline, with baseline or near-baseline resolution. We use a gradient HPLC system with a normal-phase silica column as the stationary phase, and a linear gradient of increasing polarity and ionic strength as the mobile phase. The mobile phase is composed of two buffers: Buffer A, containing acetonitrile/water/ethyl alcohol/acetic acid/0.83 M sodium acetate (800/127/68/2/3), and buffer B (400/400/68/53/79), pH 3.6. A linear gradient from 0 to 100% buffer B, with a slope of 5%/min, is started 15 min after injection. At a flow rate of 2.7 ml/min and column temperature of 45 degrees C, typical retention times for the following compounds are (in min): betaine, 10; acetylcholine, 18; choline, 22; glycerophosphocholine, 26; CDP-choline, 31; and phosphorylcholine, 40. This procedure has been applied in tracer studies of choline metabolism utilizing the neuronal NG108-15 cell line and rat hippocampal slices as model systems. While the compounds labeled in the NG108-15 cells were primarily phosphorylcholine and glycerophosphocholine, reflecting high rates of phospholipid turnover, in the hippocampal slices choline and acetylcholine were the major labeled species. Identification of individual peaks was confirmed by comparing the elution profiles of untreated cell extracts with extracts that had been treated with hydrolyzing enzymes of differing specificities. This HPLC method may be useful in studies of acetylcholine and phosphatidylcholine metabolism, and of the possible interrelationships of these compounds in cholinergic cells.

  17. Quantification of free formaldehyde in carrageenan and processed Eucheuma seaweed using high-performance liquid chromatography.

    Science.gov (United States)

    Hornshøj, Bettina Høj; Kobbelgaard, Sara; Blakemore, William R; Stapelfeldt, Henrik; Bixler, Harris J; Klinger, Markus

    2015-01-01

    In 2010 the European Commission placed a limit on the amount of free formaldehyde in carrageenan and processed Eucheuma seaweed (PES) of 5 mg kg(-1). Formaldehyde is not used in carrageenan and PES processing and accordingly one would not expect free formaldehyde to be present in carrageenan and PES. However, surprisingly high levels up to 10 mg kg(-1) have been found using the generally accepted AOAC and Hach tests. These findings are, per proposed reaction pathways, likely due to the formation of formaldehyde when sulphated galactose, the backbone of carrageenan, is hydrolysed with the strong acid used in these conventional tests. In order to minimise the risk of false-positives, which may lead to regulatory non-compliance, a new high-performance liquid chromatography (HPLC) method has been developed. Initially, carrageenan or PES is extracted with 2-propanol and subsequently reacted with 2,4-dinitrophenylhydrazine (DNPH) to form the chromophore formaldehyde-DNPH, which is finally quantified by reversed-phase HPLC with ultraviolet light detection at 355 nm. This method has been found to have a limit of detection of 0.05 mg kg(-1) and a limit of quantification of 0.2 mg kg(-1). Recoveries from samples spiked with known quantities of formaldehyde were 95-107%. Using this more specific technique, 20 samples of carrageenan and PES were tested for formaldehyde. Only one sample had a detectable content of formaldehyde (0.40 mg kg(-1)), thus demonstrating that the formaldehyde content of commercial carrageenan and PES products are well below the European Commission maximum limit of 5 mg kg(-1).

  18. [Measurement of 11 benzophenone ultraviolet-filters in cosmetics by high performance liquid chromatography].

    Science.gov (United States)

    Qu, Baocheng; Bian, Haitao; Mao, Xiqin; Li, Jin

    2015-12-01

    A sample preparation and analytical method with liquid-liquid extraction (LLE) and high performance liquid chromatography (HPLC) was developed to detect 11 benzophenone ultraviolet-filters in cosmetics. The target compounds were extracted by the mixed solutions of tetrahydrofuran (TH)/methanol/water or dichloromethane/water at proper ratios. The extracts were centrifuged and filtered to remove matrix compounds, and then analyzed by HPLC. The separation of analytes was carried out on a Diamonsil-C18 column (150 mm x 4.6 mm, 5 μm) with 0.1% (v/v) formic acid aqueous solution (containing 10 mmol/L ammonium acetate) as mobile phase A and methanol containing 0.1% (v/v) formic acid as mobile phase B. The spiked recoveries of the method (n = 7) were 93.4%-103.8% with the relative standard deviations of 0.1%-4.2%. The limits of detection (LODs) were in the range of 4.0-30 μg/g and the limits of quantitation (LOQs) ranged from 15 to 100 μg/g. The method was applied to the determination of 42 cosmetic samples randomly purchased from the supermarket in Dalian. Five benzophenone series were always detected, in which the content of benzophenone-3 in sunscreen cream and the content of benzophenone-2 in perfume were very high and reached 2 785 μg/g and 2 106 μg/g, respectively. The results showed that the developed method is efficient, reliable and sensitive, which can be applied to the determination of benzophenones in cosmetics.

  19. [Determination of 10 heterocyclic aromatic amines in beef jerky by high performance liquid chromatography].

    Science.gov (United States)

    Wan, Kehui; Peng, Zengqi; Shao, Bin; Yao, Yao; Shi, Jinming

    2012-03-01

    An analytical method was developed for the simultaneous determination of 10 heterocyclic aromatic amines (HAAs) in beef jerky by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The HAAs were eluted from an Extrelut NT 20 SPE column with 60 mL dichlormethane (containing 5% toluene), and then the extract was purified with a propylsulfonic acid silica (PRS) column and a C18 SPE column, and finally, the HAAs were stored in a methanol-ammonia solution. The separation was achieved by using a TSK-gel ODS-80 column and a gradient elution with the mobile phases of acetonitrile and 0.05 mol/L acetic acid-ammonium acetate buffer (pH 3.5). The identification and quantitative analysis of the HAAs fraction were carried out using an HPLC system with ultraviolet-fluorescence detectors. The results showed that the correlation coefficients of the 10 HAAs were all above 0.999 and the limits of detection were in the range from 0.02 to 2.46 ng/g. The recoveries of the 10 HAAs spiked in beef samples were 61.69% - 101.81% with the relative standard deviations (RSDs) between 0.28% and 7.81%. 1-Methyl-9H-pyrido[4,3-b] indole (Harman) and 9H-pyrido [4,3-b]indole (Norharman) were detected in all beef jerky, and the total HAAs content of beef jerky were between 16.65 and 60.38 ng/g. This method is with wide linear range and high sensitivity, and is enough for the analysis of the HAAs in actual meat samples.

  20. High-throughput characterization of virus-like particles by interlaced size-exclusion chromatography.

    Science.gov (United States)

    Ladd Effio, Christopher; Oelmeier, Stefan A; Hubbuch, Jürgen

    2016-03-04

    The development and manufacturing of safe and effective vaccines relies essentially on the availability of robust and precise analytical techniques. Virus-like particles (VLPs) have emerged as an important and valuable class of vaccines for the containment of infectious diseases. VLPs are produced by recombinant protein expression followed by purification procedures to minimize the levels of process- and product-related impurities. The control of these impurities is necessary during process development and manufacturing. Especially monitoring of the VLP size distribution is important for the characterization of the final vaccine product. Currently used methods require long analysis times and tailor-made assays. In this work, we present a size-exclusion ultra-high performance liquid chromatography (SE-UHPLC) method to characterize VLPs and quantify aggregates within 3.1min per sample applying interlaced injections. Four analytical SEC columns were evaluated for the analysis of human B19 parvo-VLPs and murine polyoma-VLPs. The optimized method was successfully used for the characterization of five recombinant protein-based VLPs including human papillomavirus (HPV) VLPs, human enterovirus 71 (EV71) VLPs, and chimeric hepatitis B core antigen (HBcAg) VLPs pointing out the generic applicability of the assay. Measurements were supported by transmission electron microscopy and dynamic light scattering. It was demonstrated that the iSE-UHPLC method provides a rapid, precise and robust tool for the characterization of VLPs. Two case studies on purification tools for VLP aggregates and storage conditions of HPV VLPs highlight the relevance of the analytical method for high-throughput process development and process monitoring of virus-like particles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. [Advantages in the use of high performance liquid chromatography technique for screening hemoglobinopathies in Venezuela].

    Science.gov (United States)

    Bravo-Urquiola, Martha; Arends, Anabel; Montilla, Silvia; Velásquez, Dalia; Garcìa, Gloria; Alvarez, Maritza; Guevara, José; Castillo, Omar

    2004-12-01

    The hemoglobinopathies are a very heterogeneous group of congenital hemolytic anemias, which includes hemoglobin (Hb) variants, thalassemia and hereditary persistence of fetal hemoglobin (HPFH). The aim of this study was to determine the frequency of hemoglobinopathies using the High Performance Liquid Chromatography (HPLC-CE) technique with the beta-thalassemia Short Program of Variant* Bio Rad. Four thousand blood samples from anemic patients from the Laboratorio de Investigación de Hemoglobinas Anormales, Hospital Universitario de Caracas were studied. Twenty six percent of the anemia patients had hemoglobinopathies. The Hb S was the most frequent variant found, followed by the Hb C and Hb D. Also we observed the association of beta thalassemia with Hb S and Hb C. The quantification of the Hb A by HPLC-CE allowed us to classify the double heterozygote Hb S-Beta Thalassemia in Hb S-beta+ Tal Type 1, Hb S-beta+ Tal Type 2, Hb S-beta(0) Thalassemia. The double heterozygote patients with Hb C-Beta thalassemia were also classified. The HPLC-CE is a rapid, reproducible and precise technique. The reliability of HbA2 measurement by HPLC for the detection of beta thalassaemia without any false positive or false negative results is of great advantage. HPLC may be an appropriate method for rapid screening in population surveys for beta thalassemia and hemoglobin variants carriers. Due to the high incidence of cases, in our country this is very important for their clinical management and the genetic and anthropological impact of an early and precise diagnosis.

  2. High-performance countercurrent chromatography separation of Peucedanum cervaria fruit extract for the isolation of rare coumarin derivatives.

    Science.gov (United States)

    Skalicka-Woźniak, Krystyna; Mroczek, Tomasz; Kozioł, Ewelina

    2015-01-01

    For the first time, rare major and minor compounds from fruits of Peucedanum cervaria were isolated. High-performance countercurrent chromatography with two different solvent systems, heptane/ethyl acetate/methanol/water (3:2:3:2 and 2:1:2:1, v/v), was successfully used in the reversed-phase mode. A scale-up process from analytical to semipreparative in a very short time was developed. The structures of isolated compounds were evaluated by high-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry, gas chromatography with mass spectrometry, and one- and two-dimensional NMR spectroscopy. (8S,9R)-9-(3-Methylbutenoyloxy)-O-acetyl-8,9-dihydrooroselol (compound B), (8S,9R)-9-(2-methyl-Z-butenoyloxy)-O-acetyl-8,9-dihydrooroselol (edultin, compound C), and (8S,9R)-9-acetoxy-O-(2α-methylbutyryl)-8,9-dihydrooroselol (compound D) were obtained using heptane/ethyl acetate/methanol/water (2:1:2:1, v/v) in isolation by countercurrent chromatography and the analysis of their relative stereochemistry by two-dimensional NMR spectroscopy have been performed for the first time. Additionally, heptane/ethyl acetate/methanol/water (3:2:3:2, v/v) led to the isolation of oxypeucedanin (1.2 mg; compound A). This is the first time that angular dihydrofuranocoumarin was isolated from plant extract by countercurrent chromatography. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Analysis of stereoselective drug interactions with serum proteins by high-performance affinity chromatography: A historical perspective.

    Science.gov (United States)

    Li, Zhao; Hage, David S

    2017-09-10

    The interactions of drugs with serum proteins are often stereoselective and can affect the distribution, activity, toxicity and rate of excretion of these drugs in the body. A number of approaches based on affinity chromatography, and particularly high-performance affinity chromatography (HPAC), have been used as tools to study these interactions. This review describes the general principles of affinity chromatography and HPAC as related to their use in drug binding studies. The types of serum agents that have been examined with these methods are also discussed, including human serum albumin, α1-acid glycoprotein, and lipoproteins. This is followed by a description of the various formats based on affinity chromatography and HPAC that have been used to investigate drug interactions with serum proteins and the historical development for each of these formats. Specific techniques that are discussed include zonal elution, frontal analysis, and kinetic methods such as those that make use of band-broadening measurements, peak decay analysis, or ultrafast affinity extraction. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Separation of the potential G-quadruplex ligands from the butanol extract of Zanthoxylum ailanthoides Sieb. & Zucc. by countercurrent chromatography and preparative high performance liquid chromatography.

    Science.gov (United States)

    Han, Tian; Cao, Xueli; Xu, Jing; Pei, Hairun; Zhang, Hong; Tang, Yalin

    2017-07-21

    G-quadruplex DNA structure is considered to be a very attractive target for antitumor drug design due to its unique role in maintaining telomerase activities. Therefore, discovering ligands with high stability of G-quadruplex structure is of great interest. In this paper, pH-zone refining counter current chromatography (CCC) and preparative high performance liquid chromatography (HPLC) were employed for the separation of potent G-quadruplex ligands from the n-butanol fraction of the crude extract of Zanthoxylum ailanthoides, which is a traditional Chinese medicine recently found to display high inhibitory activity against several human cancer cells. The 75% aqueous ethanol extract of the stem bark of Z. ailanthoides and its fractions with petroleum ether, ethyl acetate and n-butanol displayed almost the same G-quadruplex stabilization ability. Here, pH-zone refining CCC was used for the separation of the alkaloids from the n-butanol fraction by a seldom used solvent system composed of dichloromethane-methanol-water (4:1:2.5) with 10mM TEA in the organic stationary phase as retainer and 10mM HCl in the aqueous mobile phase as eluter. Compounds I, II and III were obtained, with purity greater than 95%, in the quantities of 31.2, 94.0, and 26.4mg respectively from 300mg of lipophilic fraction within 80min, which were identified as three tetrahydroprotoberberines isolated for the first time in this plant. In addition, a phenylpropanoid glycoside compound IV (Syringin), an isoquinoline (Magnoflorine, V), and two lignin isomers (+)-lyoniresiol-3α-O-β-d-glucopyranoside (VI) and (-)-lyoniresinol -3α-O-β-D -glucopyranoside (VII) were isolated by traditional CCC together with preparative HPLC. Compounds IV, V, VI and VII were obtained, with purity greater than 95%, in the quantities of 4.0, 13.2, 6.7, and 6.5mg respectively from 960mg of hydrophilic fraction. Among the seven isolated compounds, tetrahydroprotoberberine I, II and III were found to display remarkable

  5. Separation and purification of polyphenols from red wine extracts using high speed counter current chromatography.

    Science.gov (United States)

    Li, Yuanyuan; Li, Lingxi; Cui, Yan; Zhang, Shuting; Sun, Baoshan

    2017-06-01

    Polyphenols are important compounds of red wine owing to their contribution to sensory properties and antioxidant activities. In this study, high-speed counter-current chromatography (HSCCC) coupled with semi-preparative HPLC was used for large-scale separation and purification of polyphenols from red wine extracts. With the solvent system of hexane-ethyl acetate-water (1-50-50), various oligomeric procyanidins including monomer catechin, epicatechin, dimers B1, B2; phenolic acids including coutaric acid, caftaric acid and other type of polyphenols were largely separated within 370min and most of these compounds presented high yields (0.97mg to 13.79mg) with high purity (90.34% to 98.91%) after the semi-preparative HPLC isolation. Using the solvent system of Methyl tert-Butyl Ether (MTBE) - n-butyl alcohol- acetonitrile-water (1-40-1-50, acidified with 0.01% trifluoroacetic acid (TFA)) by one-step HSCCC of 100mg of the red wine extracts, the major anthocyanins, i.e., malvidin-3-O-glucoside, delphinidin-3-O-glucoside and peonidin-3-O-glucoside, as well as two polymeric proanthocyanidin fractions were successfully separated one another within 320min. The yields of malvidin-3-O-glucoside, delphinidin-3-O-glucoside and peonidin-3-O-glucoside were 12.12mg, 1.78mg and 11.57mg with the purity of 92.74%, 91.03% and 91.21%, respectively. Thiolysis-UPLC analysis indicated that the two polymeric proanthocyanidin fractions presented high purity, with mean degree of polymerization of 7.66±0.12 and 6.20±0.09, respectively. The further experiments on the antioxidant activities by DPPH radical test, FRAP assay and ABTS method showed that all of the isolated procyandins and anthocyanins and the two polymeric proanthocyanidin fractions, with exception of phenolic acids possessed much greater antioxidant activities compared to standard Trolox andl-ascorbic acid (2-14 times). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Highly stabilized, polymer-lipid membranes prepared on silica microparticles as stationary phases for capillary chromatography.

    Science.gov (United States)

    Gallagher, Elyssia S; Adem, Seid M; Baker, Christopher A; Ratnayaka, Saliya N; Jones, Ian W; Hall, Henry K; Saavedra, S Scott; Aspinwall, Craig A

    2015-03-13

    The ability to rapidly screen complex libraries of pharmacological modulators is paramount to modern drug discovery efforts. This task is particularly challenging for agents that interact with lipid bilayers or membrane proteins due to the limited chemical, physical, and temporal stability of conventional lipid-based chromatographic stationary phases. Here, we describe the preparation and characterization of a novel stationary phase material composed of highly stable, polymeric-phospholipid bilayers self-assembled onto silica microparticles. Polymer-lipid membranes were prepared by photochemical or redox initiated polymerization of 1,2-bis[10-(2',4'-hexadieoyloxy)decanoyl]-sn-glycero-2-phosphocholine (bis-SorbPC), a synthetic, polymerizable lipid. The resulting polymerized bis-SorbPC (poly(bis-SorbPC)) stationary phases exhibited enhanced stability compared to particles coated with 1,2-dioleoyl-sn-glycero-phosphocholine (unpolymerized) phospholipid bilayers when exposed to chemical (50 mM triton X-100 or 50% acetonitrile) and physical (15 min sonication) insults after 30 days of storage. Further, poly(bis-SorbPC)-coated particles survived slurry packing into fused silica capillaries, compared to unpolymerized lipid membranes, where the lipid bilayer was destroyed during packing. Frontal chromatographic analyses of the lipophilic small molecules acetylsalicylic acid, benzoic acid, and salicylic acid showed >44% increase in retention times (Psilica microspheres, suggesting a lipophilic retention mechanism. Phospholipid membrane-functionalized stationary phases that withstand the chemical and physical rigors of capillary LC conditions can substantially increase the efficacy of lipid membrane affinity chromatography, and represents a key advance toward the development of robust membrane protein-functionalized chromatographic stationary phases. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Evaluation of aminoacids in irradiated beans (Vigna unguiculata (L.) Walp) by high performance liquid chromatography (HPLC)

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Keila S. Cople; Souza, Luciana B.; Coelho, Maysa J.; Lima, Antonio L. Santos; Hernandes, Nilber K. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear]. E-mail: keila@ime.eb.br; Godoy, Ronoel L.O. [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil)]. E-mail: ronoel@ctaa.embrapa.br

    2007-07-01

    Fradinho-bean (Vigna unguiculata (L.) Walp) is originated from Africa and is known in Brazil as 'caupi', 'corda' or 'macassar'. It is grown in the interior of Northeast Brazil (semi-arid region) and can be found in parts of the North, being one of the most important components of people's diet in those regions. The Northeast area produces around 429,375 ton of fradinho-bean per year. Leguminous plants are very important sources of proteins, vitamins, carbohydrates and minerals. This kind of bean is an excellent source of proteins (around 23- 25% of its nutritional content), being superior to regular beans (Phaseolus vulgaris). The irradiation process is an alternative to avoid post-harvesting losses, without changing the nutritional value of food. This study has the objective to evaluate the effect of different gamma irradiation doses (0.0; 0.5; 1.0; 2.5; 5.0 and 10.0 kGy) on aminoacid content of fradinho-bean by high performance liquid chromatography (HPLC) and the accompanying of the grains during storage time of 6 months. After irradiation, the bean grains went through a milling process in order to make flour for posterior extraction. A liquid chromatographer Waters, model Alliance 2695, with fluorescent detector Waters 2475, having a mobile phase with gradient elution of sodium acetate. acetonitrile and Milli-Q water, was employed. The flux used was 1 mL/min and the injection volume of 10 {mu}L. The column (C 18 150.0 x 3.9 mm) was kept at 36 deg C. The results show that gamma irradiation is a promise process for fradinho bean during conservation storage time of 6 months, until the dose of 10.0 kGy. Even the most radio-sensitive aminoacids like aromatics and basic lateral chains were preserved. (author)

  8. Quantitative determination of triterpenoid glycosides in Fatsia japonica Decne. & Planch. using high performance liquid chromatography.

    Science.gov (United States)

    Ye, Xuewei; Yu, Siran; Lian, Xiao-Yuan; Zhang, Zhizhen

    2014-01-01

    Fatsia japonica Decne. & Planch. is a triterpenoid glycoside-rich herb with anti-inflammatory activity for the treatment of rheumatoid arthritis. A method for quantitative analysis of the complex triterpenoid glycosides in this medicinal plant has not been established so far. In this study, a high performance liquid chromatography (HPLC) method was developed for simultaneous qualification of 11 glycosides in F. japonica. The analysis was performed on an ODS-2 Hypersil column (250mm×4.6mm, 5μm) with a binary gradient mobile phase of water and acetonitrile. The established HPLC method was validated in terms of linearity, sensitivity, stability, precision, accuracy, and recovery. Results showed that this method had good linearity with R(2) at 0.99992-0.99999 in the test range of 0.04-9.00μg/μL. The limit of detection (LOD) and limit of quantification (LOQ) for the standard compounds were 0.013-0.020μg/μL and 0.040-0.060μg/μL. The relative standard deviations (RSDs%) of run variations were 0.83-1.40% for intra-day and 0.84-3.59% for inter-day. The analyzed compounds in the samples were stable for at least 36h, and the spike recoveries of the detected glycosides were 99.67-103.11%. The developed HPLC method was successfully applied for the measurements of the contents of 11 triterpenoid glycoside in different parts of F. japonica. Taken together, the HPLC method newly developed in this study could be used for qualitative and quantitative analysis of the bioactive triterpenoid glycosides in F. japonica and its products. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Separation of phosphatidylcholine and phosphatidylethanolamine by using high-performance displacement chromatography.

    Science.gov (United States)

    Zhang, Wei-Nong; He, Hai-Bo; Feng, Yu-Qi; Da, Shi-Lu

    2004-05-21

    A binary mixture of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was successfully separated by high-performance displacement chromatography (HPDC) on an 150 mm x 4.6 mm analytical silica column (3-5 microm packing), using dichloromethane-methanol (9:1, v/v) as carrier and ethanolamine as displacer. The effects of displacer concentration, flow-rate, loading amount and the composition of the sample on separation efficiency were studied. Eighty-four milligrams sample (PE:PC 1:1.16) was separated perfectly by using 83 mM ethanolamine (in carrier) as displacer at the flow-rate of 0.1 ml/min. The yields of the pure PE and PC (100% purity) were 94.8% and 87.9%, respectively and the cycle time for a single separation was about 195 min. It was valuable that the optimum loading amount (the allowed maximum of sample loading) was investigated only by using the sample to be simulated the composition of the separated actual one, because the separation efficiency was significantly affected by the composition of the sample. For the same loading amount of 175 mg, the yields of the pure PE and PC were improved greatly from 31.4 and 16.9 to 56.0 and 77.6%, respectively, when the proportion of PE to PC was adjusted from 1:1.16 to 1:4. Furthermore, the separation of PE and PC in an actual sample (soybean phospholipids) was achieved using the proposed HPDC method.

  10. Development and validation of reverse phase high performance liquid chromatography for citral analysis from essential oils.

    Science.gov (United States)

    Gaonkar, Roopa; Yallappa, S; Dhananjaya, B L; Hegde, Gurumurthy

    2016-11-15

    Citral is a widely used monoterpene aldehyde in aromatherapy, food and pesticide industries. A new validated reverse phase high performance liquid chromatography (RP - HPLC) procedure for the detection and quantification of cis-trans isomers of citral was developed. The RP-HPLC analysis was carried out using Enable C - 18G column (250×4.6mm, 5μ), with acetonitrile and water (70: 30) mobile phase in isocratic mode at 1mL/min flow. A photodiode array (PDA) detector was set at 233nm for the detection of citral. The method showed linearity, selectivity and accuracy for citral in the range of 3-100μg/mL. In order to compare the new RP-HPLC method with the available methods, one of the commercially available essential oil from Cymbopogon flexuosus was analyzed using new RP-HPLC method and the same was analyzed using GC-MS for the comparison of the method for the detection of citral. The GC-MS analysis was done using mass selective detector (MSD) showed citral content to be of 72.76%; wherein the new method showed to contain that same at 74.98%. To prove the application of the new method, essential oils were extracted from lemongrass, lemon leaves and mosambi peels by steam distillation. The citral content present in the essential and also in the condensate was analyzed. The method was found to be suitable for the analysis of citral in essential oils and water based citral formulations with a very good resolution of its components geranial and neral. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Assessment of radiochemical purity of [{sup 18}F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z., E-mail: radiofarmacoscdtn@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

    2011-07-01

    The quality control of [{sup 18}F]fludeoxyglucose ({sup 18}FDG) has received attention due to its increasing clinical use. Although the quality requirements of {sup 18}FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of {sup 18}FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. {sup 18}FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of {sup 18}FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of {sup 18}FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of {sup 18}FDG, considering operational conditions of our laboratory. (author)

  12. [Determination of aflatoxins in cashew by high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Bi, Ruifeng; Fan, Zhixian; Fu, Meng

    2011-12-01

    A method for the determination of four aflatoxins in cashew using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed. The sample was extracted with methanol-water (8: 2, v/v) solution, followed by a cleanup procedure with Florisil column. The target compounds were eluted using 5 mL acetone-water-formic acid (96: 3.5:0.5, v/v/v) solution. The eluate was dried under N2, then dissolved in 1 mL methanol. Four aflatoxins were separated in MG C18 column (100 mm x 3.0 mm, 3 microm) adopting a gradient program within 15 min. A triple quadrupole mass spectrometry equipped with an electrospray ionization source operated in the positive ion mode was used to detect the aflatoxins. The good correlation coefficients (r2 > 0.997) of the four aflatoxins were obtained within their respective linear ranges. The limits of detection (S/N = 3) were between 0.009 microg/kg and 0.04 microg/kg, and the limits of quantification (S/N = 10) were between 0.03 microg/kg and 0.12 microg/kg. The recoveries were in a range of 63.0% -78.5% with the relative standard deviations (RSDs) varied from 2.8% to 9.1%. The validation results meet the requirements of trace assay. Matrix effects were estimated and the signal suppression/enhancement ranged from 88.8% to 99.4%. The results indicate that the developed method is simple, fast, accurate, and can be applied for the determination of fours aflatoxins in cashew.

  13. Enantiomeric Separations of Pyriproxyfen and its Six Chiral Metabolites by High-Performance Liquid Chromatography.

    Science.gov (United States)

    Zhang, Chuntao; Liu, Hui; Liu, Donghui; Wang, Liying; Gao, Jing; Zhou, Zhiqiang; Wang, Peng

    2016-03-01

    Pyriproxyfen is a chiral insecticide, and over 10 metabolites have been identified in the environment. In this work the separations of the enantiomers of pyriproxyfen and its six chiral metabolites were studied by high-performance liquid chromatography (HPLC). Both normal phase and reverse phase were applied using the chiral columns Chiralpak IA, Chiralpak IB, Chiralpak IC, Chiralcel OD, Chiralcel OD-RH, Chiralpak AY-H, Chiralpak AD-H, Chiracel OJ-H, (R,R)-Whelk-O 1, and Lux Cellulose-3. The effects of the chromatographic parameters such as mobile phase composition and temperature on the separations were investigated and the enantiomers were identified with an optical rotation detector. The enantiomers of these targets could obtain complete separations (resolution factor Rs > 1.5) on Chiralpak IA, Chiralpak IB, Chiralcel OD, Chiralpak AY-H, or Chiracel OJ-H under normal conditions. Chiralcel OJ-H showed the best chiral separation results with n-hexane as mobile phase and isopropanol (IPA) as modifier. The simultaneous enantiomeric separation of pyriproxyfen and four chiral metabolites was achieved on Chiralcel OJ-H under optimized condition: n-hexane/isopropanol = 80/20, 15°C, flow rate of 0.8 ml/min, and UV detection at 230 nm. The enantiomers of pyriproxyfen and the metabolites , , and obtained complete separations on Chiralpak IA, Chiralpak IC, and Lux Cellulose-3 under reverse phase using acetonitrile/water as the mobile phase. The retention factors (k) and selectivity factors (α) decreased with increasing temperature, and the separations were better under low temperature in most cases. The work is of significance for the investigation of the environmental behaviors of pyriproxyfen on an enantiomeric level. © 2016 Wiley Periodicals, Inc.

  14. High Performance Thin Layer Chromatography method for analysis of 3,4-methylenedioxymethamphetamine in seized tablets

    Directory of Open Access Journals (Sweden)

    Boris E. Duffau

    2015-12-01

    Full Text Available Context: Consumption of synthetic drugs had increased in recent years, used as a recreational drug by young people who presume that consumption of this drug is harmless for health; however clinical studies have shown that this stimulant and its metabolites are toxic. Due to these reasons, chemical analysis of this illicit drug is crucial from the points of view of occupational medicine, toxicology, and law enforcement with the aim of pursuit the traffic of illegal drug. Aims: Implement and fully validate a rapid and simple method for detection and quantitation of MDMA by High-Performance Thin Layer Chromatography in seized samples. Methods: With the implemented method was analyzed 12 positive samples seized by Chilean police, to found the concentration of MDMA in ecstasy tablets. Results: The method was fully validated, the linearity of the method was evaluated by the calibration curve between 51.0 – 510.0 µg/band (R2 0.9977; limit of detection was 12.1 µg per band, and limit of quantitation was 36.8 µg per band. The precision of the method (RSD was lower than 5.0%. Accuracy was evaluated by determination of the percentage of MDMA recovered by the assay (99.13%, and relative Uncertainty was 6.66%. With this method, it was analyzed real seized samples of MDMA, results showed that all samples contained MDMA and concentration was between 18.15 – 59.84 % w/w. Conclusions: The method is selective, sensitive, and specific, with possible application in forensic analysis. To the best of our knowledge, this is the first report about concentration of MDMA in ecstasy pills in Chile.

  15. Synthesis of monodisperse silica microspheres and modification with diazoresin for mixed-mode ultra high performance liquid chromatography separations.

    Science.gov (United States)

    Cong, Hailin; Yu, Bing; Tian, Chao; Zhang, Shuai; Yuan, Hua

    2017-11-01

    Monodisperse silica particles with average diameters of 1.9-2.9 μm were synthesized by a modified Stöber method, in which tetraethyl orthosilicate was continuously supplied to the reaction mixture containing KCl electrolyte, water, ethanol, and ammonia. The obtained silica particles were modified by self-assembly with positively charged photosensitive diazoresin on the surface. After treatment with ultraviolet light, the ionic bonding between silica and diazoresin was converted into covalent bonding through a unique photochemistry reaction of diazoresin. Depending on the chemical structure of diazoresin and mobile phase composition, the diazoresin-modified silica stationary phase showed different separation mechanisms, including reversed phase and hydrophilic interactions. Therefore, a variety of baseline separation of benzene analogues and organic acids was achieved by using the diazoresin-modified silica particles as packing materials in ultra high performance liquid chromatography. According to the π-π interactional difference between carbon rings of fullerenes and benzene rings of diazoresin, C60 and C70 were also well separated by ultra-high performance liquid chromatography. Because it has a small size, the ∼2.5 μm monodisperse diazoresin-modified silica stationary phase shows ultra-high efficiency compared with the commercial C18 -silica high-performance liquid chromatography stationary phase with average diameters of ∼5 μm. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Comparative analysis of steroidal saponins in four Dioscoreae herbs by high performance liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Guo, Long; Zeng, Su-Ling; Zhang, Yu; Li, Ping; Liu, E-Hu

    2016-01-05

    Steroidal saponins, which exhibit multiple pharmacological effects, are the major bioactive constituents in herbal medicines from Dioscoreae species. In this study, a sensitive method based on high performance liquid chromatography-mass spectrometry (HPLC-MS) was established and validated for qualitative and quantitative analysis of steroidal saponins in four Dioscoreae herbs including Dioscoreae Nipponica Rhizome (DNR) and Dioscoreae Hypoglaucae Rhizome (DHR), Dioscoreae Spongiosae Rhizome (DSR) and Dioscoreae Rhizome (DR). A total of eleven steroidal saponins were identified by high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS). Furthermore, seven major steroidal saponins was simultaneous quantified using a high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QQQ/MS). The qualitative and quantitative analysis results indicated that the chemical composition of DNR, DHR and DSR samples exhibited a high level of global similarity, while the ingredients in DR varied greatly from the other three herbs. Moreover, principal component analysis (PCA) and hierarchical clustering analysis (HCA) were performed to compare and discriminate the Dioscoreae herbs based on the quantitative data. The results demonstrated the qualitative and quantitative analysis of steroidal saponins based on HPLC-MS is a feasible method for quality control of Dioscoreae herbs. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. High-performance liquid chromatography/high-resolution mass spectrometry for the characterization of transformation products of ionic liquids.

    Science.gov (United States)

    Fabbri, Debora; Calza, Paola; Noè, Giorgio; Santoro, Valentina; Medana, Claudio

    2017-12-15

    Ionic liquids (ILs) are a subject of active research in the field of alternative solvents. We studied the behaviour of a piperidine IL, 1-butyl-1-methylpiperidinium tetrafluoroborate (BMPA), through the elucidation of its transformation products (TPs) in water. The transformation pathways of BMPA were investigated using high-performance liquid chromatography (HPLC) combined with a hybrid LTQ-Orbitrap instrument on the basis of mass defect filtering. TPs of BMPA were identified by fragmentation patterns and accurate mass measurements. The separation and identification of 32 TPs was achieved. BMPA can be oxidized at different positions in the alkyl chains. The ultimate products corresponds to N-methyl-piperidinium and some byproducts involving ring-opening. Tests of acute toxicity, evaluated with Vibrio Fischeri bacteria, show that BMPA transformation proceeds through the formation of slightly harmful compounds. Results showed that the main transformation pathways of BMPA were alkyl chain hydroxylation/shortening and de-alkylation, and that HPLC/LTQ-Orbitrap can serve as an important analytical platform to gather the unknown TPs of ILs. Copyright © 2017 John Wiley & Sons, Ltd.

  18. A versatile method for stable carbon isotope analysis of carbohydrates by high-performance liquid chromatography/isotope ratio mass spectrometry

    NARCIS (Netherlands)

    Boschker, H.T.S.; Moerdijk-Poortvliet, T.C.W.; Van Breugel, P.; Houtekamer, M.J.; Middelburg, J.J.

    2008-01-01

    We have developed a method to analyze stable carbon isotope (13C/12C) ratios in a variety of carbohydrates using high-performance liquid chromatography/isotope ratio mass spectrometry (HPLC/IRMS). The chromatography is based on strong anion-exchange columns with low strength NaOH eluents. An eluent

  19. Isolation and Purification of Oridonin from the Whole Plant of Isodon rubescens by High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    ChunYue Yu

    2011-09-01

    Full Text Available Semi-preparative high-speed counter-current chromatography (HSCCC was successfully used for isolation and purification of oridonin from Isodon rubescens by using a two-phase-solvent system composed of n-hexane-ethyl acetate-methanol-water (2.8:5:2.8:5, v/v/v/v. The targeted compound isolated, collected and purified by HSCCC was analyzed by high performance liquid chromatography (HPLC. A total of 40.6 mg of oridonin with the purity of 73.5% was obtained in less than 100 min from 100 mg of crude Isodon rubescens extract. The chemical structure of the compound was identified by IR, 1H-NMR and 13C-NMR.

  20. Separation and determination of alditols and sugars by high-pH anion-exchange chromatography with pulsed amperometric detection

    DEFF Research Database (Denmark)

    Andersen, Rikke; Sørensen, A.

    2000-01-01

    Carbohydrates such as alditols (polyols or sugar alcohols), monosaccharides and disaccharides are separated as anions by anion-exchange chromatography with a sodium hydroxide eluent, MA1 CarboPac column and pulsed amperometric detection. We report a high-pH anion-exchange chromatographic-pulsed a......Carbohydrates such as alditols (polyols or sugar alcohols), monosaccharides and disaccharides are separated as anions by anion-exchange chromatography with a sodium hydroxide eluent, MA1 CarboPac column and pulsed amperometric detection. We report a high-pH anion-exchange chromatographic...... demonstrated by the analysis of 46 relevant samples and by participation twice in the Food Analysis Performance Assessment Scheme (FAPAS) testing programme for food additives. (C) 2000 Elsevier Science BN. All rights reserved....

  1. Highly sensitive reversed-phase high-performance liquid chromatography assay for the detection of Tamm-Horsfall protein in human urine.

    Science.gov (United States)

    Akimoto, Masaru; Hokazono, Eisaku; Ota, Eri; Tateishi, Takiko; Kayamori, Yuzo

    2016-01-01

    Tamm-Horsfall protein (also known as uromodulin) is the most abundant urinary protein in healthy individuals. Since initially characterized by Tamm and Horsfall, the amount of urinary excretion and structural mutations of Tamm-Horsfall protein is associated with kidney diseases. However, currently available assays for Tamm-Horsfall protein, which are mainly enzyme-linked immunosorbent assay-based, suffer from poor reproducibility and might give false negative results. We developed a novel, quantitative assay for Tamm-Horsfall protein using reversed-phase high-performance liquid chromatography. A precipitation pretreatment avoided urine matrix interference and excessive sample dilution. High-performance liquid chromatography optimization based on polarity allowed excellent separation of Tamm-Horsfall protein from other major urine components. Our method exhibited high precision (based on the relative standard deviations of intraday [≤2.77%] and interday [≤5.35%] repetitions). The Tamm-Horsfall protein recovery rate was 100.0-104.2%. The mean Tamm-Horsfall protein concentration in 25 healthy individuals was 31.6 ± 18.8 mg/g creatinine. There was a strong correlation between data obtained by high-performance liquid chromatography and enzyme-linked immunosorbent assay (r = 0.906), but enzyme-linked immunosorbent assay values tended to be lower than high-performance liquid chromatography values at low Tamm-Horsfall protein concentrations. The high sensitivity and reproducibility of our Tamm-Horsfall protein assay will reduce the number of false negative results of the sample compared with enzyme-linked immunosorbent assay. Moreover, our method is superior to other high-performance liquid chromatography methods, and a simple protocol will facilitate further research on the physiological role of Tamm-Horsfall protein. © The Author(s) 2015.

  2. Role of liquid chromatography-high-resolution mass spectrometry (LC-HR/MS) in clinical toxicology.

    Science.gov (United States)

    Wu, Alan Hb; Gerona, Roy; Armenian, Patil; French, Deborah; Petrie, Matthew; Lynch, Kara L

    2012-09-01

    Gas chromatography (GC) and liquid chromatography (LC) coupled with mass spectrometry (MS) are widely used to confirm drug screening results and for urine screening in presumed intoxicated patients. These techniques are better suited to targeted analysis than to general unknown screening and, due to the complexity of testing, results are seldom available rapidly enough to contribute to the immediate care of the patient. High resolution (HR)/MS with time-of-flight (TOF) or orbitrap instruments offer potential advantages in clinical toxicology. COMPARISON OF GC-MS, LC-MS/MS AND LC-HR/MS: For unknown analyses, GC-MS and LC-MS/MS require comparison of full-scan spectra against preestablished libraries. Operation in full-scan mode greatly reduces sensitivity and some drugs present in low but significant concentrations may be missed. Selected ion monitoring (SIM) in GC/MS and selected reaction monitoring (SRM) in LC-MS/MS, where only targeted ions are monitored, increase sensitivity but require prior knowledge of what compound is to be measured. LC-HR/MS offers mass assignment with an accuracy of 0.001 atomic mass units (amu) compared with 1 amu in conventional MS. Tentative identification is thus directed to a very limited set of compounds (or even one unique compound) based on the exact molecular formula rather than a fragmentation pattern, since HR/MS can discriminate between compounds with the same nominal molecular mass. LC-MS/MS has clear advantages over GC/MS in ease and speed of sample preparation and the opportunities for its automation. LC-HR/MS is more suitable to clinical toxicology because the drugs present in a sample are rarely known a priori, and tentative identifications of unknowns can be made without the availability of a reference standard or a library spectrum. Blood can be used in preference to urine which is more relevant to the patient's current clinical situation. A literature search was conducted using PUBMED for clinical toxicology, adulterants

  3. Determination of Thiophanate-methyl in Tamoto by High Performance Liquid Chromatography-triple Quadrupole Tandem Mass Spectometry

    OpenAIRE

    XU, WEI-FENG; Han, Kai; SUN Yu-jie; PAN Kang-biao

    2014-01-01

    To evaluate the safety of use of 70% thiophanate-methyl wettable powders in tomato, a supervised trial experiment was conducted to study the residues in tomato. A method of determining thiophanate-methyl by high performance liquid chromatography-tandem mass spectrometry(LC-MSMS)was established. Acetonitrile was used as an extraction solvent, and PSA and anhydrous magnesium were used for sample purifying. Samples were determined and quantified by LC-MSMS in the multiple reaction monitoring mod...

  4. Rapid and accurate simultaneous determination of abamectin and ivermectin in bovine milk by high performance liquid chromatography with fluorescence detection

    OpenAIRE

    Kolberg, D. I. S.; Presta, M.A.; Wickert, C.; Adaime,M. B.; R. Zanella

    2009-01-01

    An analytical method using high performance liquid chromatography with fluorescence detection for the simultaneous determination of abamectin and ivermectin in bovine milk was developed and validated. The best recovery results were achieved by using acetonitrile for extraction of the compounds followed by solid phase extraction in cartridges containing C18 for the purification of the extract. Pre-column derivatization was accomplished with N-methylimidazole and trifluoroacetic anhydride. The ...

  5. Rapid determination of alpha tocopherol in olive oil adulterated with sunflower oil by reversed phase high-performance liquid chromatography

    OpenAIRE

    Bakre, S.M.; Gadmale, D. K.; Toche, R. B.; V. B. GAIKWAD

    2014-01-01

    A new method is developed to determine the presence of sunflower oil in olive oil. α-tocopherol is selected as discriminating parameter for detecting sunflower oil adulterant in olive oil. Admixtures of olive oil and sunflower oil (5 %, 10 %, 15 % and 20 % sunflower oil in olive oil) are prepared. These admixtures are analysed by reversed phase high pressure liquid chromatography coupled with fluorescence detector. The sample preparation does not require saponification or addition of antioxid...

  6. High-Pressure Liquid Chromatography of Irradiated Nuclear Fue - Separation of Neodymium for Burn-up Determination

    DEFF Research Database (Denmark)

    Larsen, N. R.

    1979-01-01

    Neodymium is separated from solutions of spent nuclear fuel by high-pressure liquid chromatography in methanol-nitric acid-water media using an anion-exchange column. Chromatograms obtained by monitoring at 280 nm, illustrate the difficulties especially with the fission product ruthenium in nuclear...... chemistry. Preseparation of the rare earths and trivalent actinides using a di(2-ethylhexyl)phosphoric acid/kieselguhr column is described....

  7. Application of microscopy technique and high performance liquid chromatography for quality assessment of Polygonum multiflorum Thunb. (Heshouwu)

    OpenAIRE

    Li Liang; Zhongzhen Zhao; Tingguo Kang

    2014-01-01

    Background: The technique of microscopy has been applied for identification of Chinese materia medica (CMM) since decades. However, very few scientific publications report the combination of conventional microscopy and high performance liquid chromatography (HPLC) techniques for further application to quality assessment of CMM. Objective: The objective of this study is to analyze the quality of the dried root tuber of Polygonum multiflorum Thunb. (Heshouwu) and to establish the relationships ...

  8. Microcytic hypochromic anemia: Should high performance liquid chromatography be used routinely for screening anemic and antenatal patients?

    OpenAIRE

    Joseph Philip; Ravi Shankar Sarkar; Neerja Kushwaha

    2013-01-01

    Background: Hemoglobinopathies are the most common inherited red cell disorders worldwide. Identification of these disorders is immensely important epidemiologically and for improved management protocols. Aim and Objectives: Our aim was to determine the prevalence of hemoglobinopathies in patients with microcytic hypochromic anemia and to assess the suitability of using high performance liquid chromatography (HPLC) routinely for screening antenatal cases and patients with anemia. Materials an...

  9. Analysis of cholic acid amides by high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    V. I. Gusarov

    2012-12-01

    Full Text Available The method of preparative purification of the obtained amides of cholic acid by HPLC was developed. The structure of the compounds was confirmed by 1H NMR spectroscopy and mass spectrometry. Purity of compounds was confi rmed by chromatography.

  10. Isolation and purification of alkaloids from lotus leaves by ionic-liquid-modified high-speed countercurrent chromatography.

    Science.gov (United States)

    Wu, Nan; Xie, Huihui; Fang, Yingtong; Liu, Yuanyuan; Xi, Xingjun; Chu, Qiao; Dong, Genlai; Lan, Tao; Wei, Yun

    2017-10-31

    An effective high-speed countercurrent chromatography method was successfully established by using ionic liquids as the modifier of the two-phase solvent system. Adding a small amount of ionic liquids significantly shortens the separation time and improves the separation efficiency. The conditions of ionic-liquid-modified high-speed countercurrent chromatography including solvent systems, types and content of added ionic liquids, and ionic liquids post-treatment were investigated. The established method was successfully applied to separate alkaloids from lotus leaves using a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water/[C4 mim][BF4 ] (1:5:1:5:0.15, v/v). Four alkaloids pronuciferine (1.7 mg), N-nornuciferine (4.3 mg), nuciferine (3.1 mg), and roemerine (2.1 mg) were obtained with the purities of 90.53, 92.25, 99.86 and 98.63%, respectively from 100 mg crude extract of lotus leaves. The results indicated that ionic-liquid-modified high-speed countercurrent chromatography method was suitable for alkaloid separation from lotus leaves and would be a promising method for the separation of alkaloids from other natural products. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Effect-directed analysis via hyphenated high-performance thin-layer chromatography for bioanalytical profiling of sunflower leaves.

    Science.gov (United States)

    Móricz, Ágnes M; Ott, Péter G; Yüce, Imanuel; Darcsi, András; Béni, Szabolcs; Morlock, Gertrud E

    2018-01-19

    High-performance thin-layer chromatography (HPTLC) coupled with effect-directed analysis was used for non-targeted screening of sunflower leaf extract for components exhibiting antioxidant, antibacterial and/or cholinesterase enzyme inhibitory effects. The active compounds were characterized by HPTLC-electrospray ionization-high resolution mass spectrometry (ESI-HRMS) and HPTLC-Direct Analysis in Real Time (DART)-MS/MS. The latter ambient ionization technique (less soft than ESI) resulted in oxidation and fragmentation products and characteristic fragment ions. NMR spectroscopy after targeted isolation via preparative normal phase flash chromatography and semi-preparative reversed phase high-performance liquid chromatography supported the identification of two diterpenes to be (-)-kaur-16-en-19-oic acid and 15-α-angeloyloxy-ent-kaur-16-en-19-oic acid. Both compounds found to be multi-potent as they inhibited acetylcholinesterase and butyrylcholinesterase and showed antibacterial effects against Gram-positive Bacillus subtilis and Gram-negative Aliivibrio fischeri bacteria. Kaurenoic acid was also active against the Gram-negative pepper pathogenic Xanthomonas euvesicatoria bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Validation of high performance liquid chromatography method for determination of meloxicam loaded PEGylated nanocapsules

    Directory of Open Access Journals (Sweden)

    Francine Rodrigues Ianiski

    2015-12-01

    Full Text Available abstract A method to ensure that an analytical method will produce reliable and interpretable information about the sample must first be validated, making sure that the results can be trusted and traced. In this study, we propose to validate an analytical high performance liquid chromatography (HPLC method for the quantitation of meloxicam loaded PEGylated nanocapsules(M-PEGNC. We performed a validation study, evaluated parameters including specificity, linearity, quantification limit, detection limit, accuracy, precision and robustness. PEGylated nanocapsules were prepared by interfacial deposition of preformed polymer, and the particle size, polydispersity index, zeta potential, pH value and encapsulation efficiency were characterized. The proposed HPLC method provides selective, linear results in the range of 1.0-40.0 μg/mL; quantification and detection limits were 1.78 μg/mL and 0.59 μg/mL, respectively; relative standard deviation for repeatability was 1.35% and intermediate precision was 0.41% and 0.61% for analyst 1 and analyst 2, respectively; accuracy between 99.23 and 101.79%; robustness between 97.13 and 98.45% for the quantification of M-PEGNC. Mean particle diameters were 261 ± 13 nm and 249 ± 20 nm, polydispersity index was 0.15 ± 0.07 and 0.17 ± 0.06, pH values were 5.0 ± 0.2 and 5.2 ± 0.1, and zeta-potential values were -37.9 ± 3.2 mV e -31.8 ± 2.8 mV for M-PEGNC and placebo(B-PEGNC, respectively. In conclusion, the proposed analytical method is suitable for the quality control of M-PEGNC. Moreover, suspensions showed monomodal size distributions and low polydispersity index indicating high homogeneity of formulations with narrow size distributions, and appropriate pH and zeta potential. The extraction process was efficient for release of meloxicam from nanostructured systems.

  13. Efficient purification of paclitaxel from yews using high-performance displacement chromatography technique.

    Science.gov (United States)

    Watchueng, Jean; Kamnaing, Pierre; Gao, Jin-Ming; Kiyota, Taira; Yeboah, Faustinus; Konishi, Yasuo

    2011-05-20

    Paclitaxel was purified using high-performance displacement chromatography (HPDC) technique, but not by the mechanism of HPDC. On small scale, paclitaxel was extracted with methanol from dry needles of Taxus canadensis and was enriched by extracting with chloroform after removing water-soluble hydrophilic components and hexane-soluble hydrophobic components. Then, 93-99% purity of paclitaxel was obtained using the HPDC technique. On large scale, taxanes were enriched by solvent partitioning between acetic acid/MeOH/H(2)O and hexane and extracted with CH(2)Cl(2). Taxanes except paclitaxel were further removed by extracting with methanol-water-trifluoroacetic acid (1.0:98.9:0.1, v/v/v). Applying HPDC technique to water-insoluble substances is problematic as this method requires a highly aqueous solvent system. In order to overcome this incompatibility, a system was set up where paclitaxel, although in low concentration, was extracted by methanol-water-trifluoroacetic acid (10.0:89.9:0.1, v/v/v). Recycling the extracting solvent to ensure minimal volume, the extracted paclitaxel was adsorbed on a C(18) trap column. A C(18) column of 4.6mm internal diameter was then connected to the trap column. The HPDC technique was thus carried out using an isocratic acetonitrile-water-trifluoroacetic acid (30.0:69.9:0.1, v/v/v) mobile phase consisting of a displacer cetylpyridinium trifluoroacetate (3mg/mL). Paclitaxel was co-eluted with the displacer and spontaneously crystallized. The crystal (114mg) showed 99.4% purity and only 10% of paclitaxel in the starting crude extract was lost during the enrichment/purification processes. This large scale purification method was successfully applied to purify paclitaxel from Chinese yew in small scale, suggesting general applicability of the method. This is the first report of purifying a water-insoluble natural product using HPDC technique. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  14. Quantification of antidepressants and antipsychotics in human serum by precipitation and ultra high pressure liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Hasselstrøm, Jørgen Bo

    2011-01-01

    precipitated with zinc sulphate and methanol containing a stable isotope labelled analog for each analyte. Quantitative analysis was performed by ultra high pressure liquid chromatography combined with a tandem mass spectrometer using a Zorbax SB-C8 column (2.0×50mm; 1.8m) with a mobile phase consisting of 0.......1% formic acid in water and methanol, respectively. The total run time of the chromatography was 4 min. Precision and trueness varied from 2.6% to 14.9% and 87.6% to 103.5%, respectively. At the lower limit of quantification, precision was up to 17.9% and trueness varied from 89.5% to 111.5%. A five point...

  15. High-throughput oxidation screen of antibody-drug conjugates by analytical protein A chromatography following IdeS digest.

    Science.gov (United States)

    Buecheler, Jakob W; Winzer, Matthias; Weber, Christian; Gieseler, Henning

    2018-01-30

    Oxidation of protein therapeutics is a major chemical degradation pathway which may impact bioactivity, serum half-life and stability. Therefore, oxidation is a relevant parameter which has to be monitored throughout formulation development. Methods such as HIC, RPLC and LC/MS achieve a separation of oxidized and non-oxidized species by differences in hydrophobicity. Antibody-drug conjugates (ADC) although are highly more complex due to the heterogeneity in linker, drug, drug-to-antibody ratio (DAR) and conjugation site. The analytical protein A chromatography can provide a simple and fast alternative to these common methods. A miniature analytical protein A chromatography method in combination with an IdeS digest was developed to analyse ADCs. The IdeS digest efficiency of an IgG1 was monitored using SEC-HPLC and non-reducing SDS-PAGE. An antibody-fluorescent dye conjugate was conjugated at different dye-to-antibody ratios as model construct to mimic an ADC. With IdeS, an almost complete digest of a model IgG1 can be achieved (digested protein amount >98%). This enables subsequent analytical protein A chromatography, which consequently eliminates any interference of payload with the stationary phase. A novel high-throughput method for an interchain cysteine-linked ADC oxidation screens during formulation development was developed. © 2018 Royal Pharmaceutical Society.

  16. Comparison of the response of four aerosol detectors used with ultra high pressure liquid chromatography.

    Science.gov (United States)

    Hutchinson, Joseph P; Li, Jianfeng; Farrell, William; Groeber, Elizabeth; Szucs, Roman; Dicinoski, Greg; Haddad, Paul R

    2011-03-25

    The responses of four different types of aerosol detectors have been evaluated and compared to establish their potential use as a universal detector in conjunction with ultra high pressure liquid chromatography (UHPLC). Two charged-aerosol detectors, namely Corona CAD and Corona Ultra, and also two different types of light-scattering detectors (an evaporative light scattering detector, and a nano-quantity analyte detector [NQAD]) were evaluated. The responses of these detectors were systematically investigated under changing experimental and instrumental parameters, such as the mobile phase flow-rate, analyte concentration, mobile phase composition, nebulizer temperature, evaporator temperature, evaporator gas flow-rate and instrumental signal filtering after detection. It was found that these parameters exerted non-linear effects on the responses of the aerosol detectors and must therefore be considered when designing analytical separation conditions, particularly when gradient elution is performed. Identical reversed-phase gradient separations were compared on all four aerosol detectors and further compared with UV detection at 200 nm. The aerosol detectors were able to detect all 11 analytes in a test set comprising species having a variety of physicochemical properties, whilst UV detection was applicable only to those analytes containing chromophores. The reproducibility of the detector response for 11 analytes over 10 consecutive separations was found to be approximately 5% for the charged-aerosol detectors and approximately 11% for the light-scattering detectors. The tested analytes included semi-volatile species which exhibited a more variable response on the aerosol detectors. Peak efficiencies were generally better on the aerosol detectors in comparison to UV detection and particularly so for the light-scattering detectors which exhibited efficiencies of around 110,000 plates per metre. Limits of detection were calculated using different mobile phase

  17. Improved method for the determination of triacylglycerols in olive oils by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Cert, A.

    2003-06-01

    Full Text Available The analysis of triacylglycerols has great importance as quality control and origin determination aid in olive oils analytical methodologies. New improvements in the analysis of triacylglycerols by high-performance liquid chromatography in olive oils are developed in order to increase the separation between LLL/OLLn and OLL/OOLn critical pairs used for detection of seed oils in olive oils. Elution with acetone/acetonitrile (55:45 using gradient temperature and isothermal elution with propionitrile were investigated, in comparison with the European Union official method. The best resolution was achieved using propionitrile at 20 ºC. Although the HPLC profile was similar using propionitrile and acetone/acetonitrile, differences in minor triacylglycerols contributing to each HPLC peak were encountered. The precision of the method was good.El análisis de triacilgliceroles tiene gran importancia como herramienta en el control de calidad y en la determinación del origen de los aceites de oliva. Nuevas mejoras en el análisis de triacilgliceroles en aceite de oliva mediante cromatografía líquida de alta eficacia se han desarrollado para mejorar la separación entre las parejas críticas LLL/OLLn y OLL/OOLn usadas en la detección de aceites de semilla en aceite de oliva. Eluciones con acetona/acetonitrilo (55:45 usando gradiente de temperatura y elución con propionitrilo en condiciones isotérmicas han sido investigadas en comparación con el método oficial de la Unión Europea. La mejor resolución se consiguió usando propionitrilo como eluyente a 20 ºC. Aunque el perfil cromatográfico obtenido usando propionitrilo fue similar al obtenido usando acetona/acetonitrilo, se encontraron diferencias en los triacilgliceroles minoritarios que contribuyen a cada pico cromatográfico. La precisión del método fue buena.

  18. Quantitation of artemether in pharmaceutical raw material and injections by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Isabela da Costa César

    2009-12-01

    Full Text Available The quantitation of artemether in both pharmaceutical raw material and injections was carried out by high performance liquid chromatography (HPLC with ultraviolet detection. A Zorbax C18 column (150 x 4.6 mm; 5 μm, at 30 °C, and a mobile phase composed of acetonitrile and water (70:30, at a flow rate of 1ml/min, were used. The detection wavelength was 216 nm and the injection volume was 20 μL. The method proved to be linear (r²=0.9999, precise (RSD A quantificação de artemeter em matéria-prima farmacêutica e solução injetável foi realizada por cromatografia líquida de alta eficiência (CLAE com detecção na região do ultravioleta. Empregou-se coluna Zorbax C18 (150 x 4.6 mm; 5 μm, mantida a 30 °C, e fase móvel composta por acetonitrila e água (70:30, com fluxo de 1 ml/min. A detecção foi realizada a 216 nm, e o volume de injeção foi 20 μl. O método se mostrou linear (r²=0,9999, preciso (DPR < 2,0% para precisão intra-dia e inter-dias e seletivo em relação a possíveis impurezas e excipientes das amostras. Os limites de detecção e quantificação obtidos foram 8 μg/mL e 25 μg/mL, respectivamente. O teor médio de artemeter obtido na análise da matéria-prima farmacêutica foi 99,26% e na solução injetável, 102,08%. O método otimizado e validado pode ser utilizado com sucesso para análises rotineiras em controle de qualidade.

  19. Analysis by high-performance liquid chromatography of teucrin A in beverages flavoured with an extract of Teucrium chamaedrys L.

    Science.gov (United States)

    Bosisio, E; Giavarini, F; Dell'Agli, M; Galli, G; Galli, C L

    2004-05-01

    Due to its liver toxicity, the medicinal use of germander (Teucrium chamaedrys L.) was banned in some countries. Nevertheless, alcoholic extracts are still permitted as flavour ingredients since they are fundamental in providing a bitter aromatic taste. Teucrin A represents the substance of major concern regarding the potential toxicity of germander. Hence, teucrin A represents the best analytical and toxicological marker of alcoholic extracts of T. chamaedrys. A sensitive high-performance liquid chromatography method to detect teucrin A in beverages is reported. Teucrin A was prepared by isolation from the plant extract using column chromatography and crystallization. The identity and purity (99%) were established by melting point, nuclear magnetic resonance and liquid chromatography-mass spectrometry. The high-performance liquid chromatography procedure was validated and its intra- and interday performance was established (relative standard deviation chamaedrys spiked with a range of concentrations of teucrin A. The limit of detection was 0.1 ppm and the limit of quantification was 0.3 ppm. Teucrin A accounted for about 70% of the neo-clerodane diterpenoids found in the total extract of a specimen of T. chamaedrys. The content (+/- standard deviation) in 18 batches of different geographical origin was 2338 +/- 740 ppm, per cent coefficient of variation = 32, minimum-maximum = 999 - 3445 ppm. The mean level of teucrin A in 10 bottles of the same brand was 6.1 +/- 0.8 ppm, per cent coefficient of variation = 12. In 10 different brands found on the Italian market, the content of teucrin A ranged from not detectable to 10 ppm.

  20. Employment of High-Performance Thin-Layer Chromatography for the Quantification of Oleuropein in Olive Leaves and the Selection of a Suitable Solvent System for Its Isolation with Centrifugal Partition Chromatography.

    Science.gov (United States)

    Boka, Vasiliki-Ioanna; Argyropoulou, Aikaterini; Gikas, Evangelos; Angelis, Apostolis; Aligiannis, Nektarios; Skaltsounis, Alexios-Leandros

    2015-11-01

    A high-performance thin-layer chromatographic methodology was developed and validated for the isolation and quantitative determination of oleuropein in two extracts of Olea europaea leaves. OLE_A was a crude acetone extract, while OLE_AA was its defatted residue. Initially, high-performance thin-layer chromatography was employed for the purification process of oleuropein with fast centrifugal partition chromatography, replacing high-performance liquid-chromatography, in the stage of the determination of the distribution coefficient and the retention volume. A densitometric method was developed for the determination of the distribution coefficients, KC = CS/CM. The total concentrations of the target compound in the stationary phase (CS) and in the mobile phase (CM) were calculated by the area measured in the high-performance thin-layer chromatogram. The estimated Kc was also used for the calculation of the retention volume, VR, with a chromatographic retention equation. The obtained data were successfully applied for the purification of oleuropein and the experimental results confirmed the theoretical predictions, indicating that high-performance thin-layer chromatography could be an important counterpart in the phytochemical study of natural products. The isolated oleuropein (purity > 95%) was subsequently used for the estimation of its content in each extract with a simple, sensitive and accurate high-performance thin-layer chromatography method. The best fit calibration curve from 1.0 µg/track to 6.0 µg/track of oleuropein was polynomial and the quantification was achieved by UV detection at λ 240 nm. The method was validated giving rise to an efficient and high-throughput procedure, with the relative standard deviation % of repeatability and intermediate precision not exceeding 4.9% and accuracy between 92% and 98% (recovery rates). Moreover, the method was validated for robustness, limit of quantitation, and limit of detection. The amount of oleuropein for

  1. [High speed separation and quantitation of Ralstonia solanacearum of different virulence using high performance ion exchange chromatography].

    Science.gov (United States)

    Lin, Juan; Ma, Cheng; Liu, Shutao; Wu, Lingling; Rao, Pingfan

    2007-01-01

    High performance ion exchange chromatography coupled with laser light scattering instrument was employed for the rapid separation and quantitation of Ralstonia solanacearum of different virulence. The pure culture of Ralstonia solanacearum was successfully separated into three characteristic fractions. Each fraction was collected and inoculated onto 2,3,5-triphenyltetrazolium chloride (TTC) plates to identify its virulence. The shapes and colors of the colonies were imaged, and the average attenuation index (attenuation index = red spot diameter of colony/total colony diameter) of ten colonies of each fraction was carefully determined. Furthermore, each fraction was inoculated into SPA liquid media at 30 degrees C with shaking (200 r/min) for 48 h, the cells were harvested, suspended at a density of 1.2 x 10(9) cfu/mL, and applied to infect tomato tissue culture plantlets using leaf-cutting method. The infection mortality of the tomato tissue culture plantlets was recorded from 1 to 9 days after inoculation. The results showed that the virulences of each fraction were different on the basis of attenuation index and infection mortality. The virulence of peak 3 fraction was the strongest. On the contrary, the virulence of peak 1 fraction was the weakest. In addition, the linear relationships between different injection volumes (1 - 180 microL) and their peak areas were investigated. The linearity was good within the range of the bacterial number of 9 x 10(6) - 9 x 10(8) (r = 0.99). This method can be potentially used as a novel tool for the rapid separation and quantitation of Ralstonia solanacearum of different virulences.

  2. Validating a High Performance Liquid Chromatography-Ion Chromatography (HPLC-IC) Method with Conductivity Detection After Chemical Suppression for Water Fluoride Estimation.

    Science.gov (United States)

    Bondu, Joseph Dian; Selvakumar, R; Fleming, Jude Joseph

    2018-01-01

    A variety of methods, including the Ion Selective Electrode (ISE), have been used for estimation of fluoride levels in drinking water. But as these methods suffer many drawbacks, the newer method of IC has replaced many of these methods. The study aimed at (1) validating IC for estimation of fluoride levels in drinking water and (2) to assess drinking water fluoride levels of villages in and around Vellore district using IC. Forty nine paired drinking water samples were measured using ISE and IC method (Metrohm). Water samples from 165 randomly selected villages in and around Vellore district were collected for fluoride estimation over 1 year. Standardization of IC method showed good within run precision, linearity and coefficient of variance with correlation coefficient R2 = 0.998. The limit of detection was 0.027 ppm and limit of quantification was 0.083 ppm. Among 165 villages, 46.1% of the villages recorded water fluoride levels >1.00 ppm from which 19.4% had levels ranging from 1 to 1.5 ppm, 10.9% had recorded levels 1.5-2 ppm and about 12.7% had levels of 2.0-3.0 ppm. Three percent of villages had more than 3.0 ppm fluoride in the water tested. Most (44.42%) of these villages belonged to Jolarpet taluk with moderate to high (0.86-3.56 ppm) water fluoride levels. Ion Chromatography method has been validated and is therefore a reliable method in assessment of fluoride levels in the drinking water. While the residents of Jolarpet taluk (Vellore distict) are found to be at a high risk of developing dental and skeletal fluorosis.

  3. Migrating components in a polyurethane laminating adhesive identified using gas chromatography/mass spectrometry.

    Science.gov (United States)

    Athenstädt, Behnusch; Fünfrocken, Michael; Schmidt, Torsten C

    2012-08-30

    Plastics are increasingly used as packaging materials for pharmaceuticals. However, diffusion of compounds in plastic into drugs may endanger patients' health. Regulatory authorities therefore demand detailed information about leachable compounds in plastics. Here we identify migrating components of a sterilization-resistant polyurethane (PUR) adhesive used in the primary packaging for an aqueous pharmaceutical. This identification is an essential first step for quantification and toxicological evaluation of the compounds. We used various hyphenated mass spectrometry (MS) methods: gas chromatography (GC/MS) with either electron impact ionization or chemical ionization, and high resolution liquid chromatography (LC/MS) with electrospray ionization. Of the 13 migrating substances detected, 11 are cyclic esters with characteristic fragmentation schemes apparent from their mass spectra. These esters are formed as by-products during the reaction of adipic and isophthalic acid with monoethylene glycol and diethyelene glycol. A cyclic ester of isophthalic acid and tetraethylene glycol and a product of the reaction of isophoron diisocyanate with methanol were clearly identified. Complementary use of several hyphenated mass spectrometric methods enables successful identification of leachable compounds in the PUR adhesive under study. This opens the way for quantification and evaluation of the potential toxicities of these compounds. Despite the range of compositions of PUR laminates, the approach presented here may be applicable for the qualitative assessment of all PURs. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Urinary detection of conjugated and unconjugated anabolic steroids by dilute-and-shoot liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Tudela, Eva; Deventer, Koen; Geldof, Lore; Van Eenoo, Peter

    2015-02-01

    Anabolic androgenic steroids (AAS) are an important class of doping agents. The metabolism of these substances is generally very extensive and includes phase-I and phase-II pathways. In this work, a comprehensive detection of these metabolites is described using a 2-fold dilution of urine and subsequent analysis by liquid chromatography-high resolution mass spectrometry (LC-HRMS). The method was applied to study 32 different metabolites, excreted free or conjugated (glucuronide or sulfate), which permit the detection of misuse of at least 21 anabolic steroids. The method has been fully validated for 21 target compounds (8 glucuronide, 1 sulfate and 12 free steroids) and 18 out of 21 compounds had detection limits in the range of 1-10 ng mL(-1) in urine. For the conjugated compounds, for which no reference standards are available, metabolites were synthesized in vitro or excretion studies were investigated. The detection limits for these compounds ranged between 0.5 and 18 ng mL(-1) in urine. The simple and straightforward methodology complements the traditional methods based on hydrolysis, liquid-liquid extraction, derivatization and analysis by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Copyright © 2014 John Wiley & Sons, Ltd.

  5. Factors influencing the separation of oligonucleotides using reversed-phase/ion-exchange mixed-mode high performance liquid chromatography columns.

    Science.gov (United States)

    Biba, Mirlinda; Jiang, Eileen; Mao, Bing; Zewge, Daniel; Foley, Joe P; Welch, Christopher J

    2013-08-23

    New mixed-mode columns consisting of reversed-phase and ion-exchange separation modes were evaluated for the analysis of short RNA oligonucleotides (∼20mers). Conventional analysis for these samples typically involves using two complementary methods: strong anion-exchange liquid chromatography (SAX-LC) for separation based on charge, and ion-pair reversed-phase liquid chromatography (IP-RPLC) for separation based on hydrophobicity. Recently introduced mixed-mode high performance liquid chromatography (HPLC) columns combine both reversed-phase and ion-exchange modes, potentially offering a simpler analysis by combining the benefits of both separation modes into a single method. Analysis of a variety of RNA oligonucleotide samples using three different mixed-mode stationary phases showed some distinct benefits for oligonucleotide separation and analysis. When using these mixed-mode columns with typical IP-RPLC mobile phase conditions, such as ammonium acetate or triethylammonium acetate as the primary ion-pair reagent, the separation was mainly based on the IP-RPLC mode. However, when changing the mobile phase conditions to those more typical for SAX-LC, such as salt gradients with NaCl or NaBr, very different separation patterns were observed due to mixed-mode interactions. In addition, the Scherzo SW-C18 and SM-C18 columns with sodium chloride or sodium bromide salt gradients also showed significant improvements in peak shape. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. High yield of recombinant human Apolipoprotein A-I expressed in Pichia pastoris by using mixed-mode chromatography.

    Science.gov (United States)

    Narasimhan Janakiraman, Vignesh; Noubhani, Abdelmajid; Venkataraman, Krishnan; Vijayalakshmi, Mookambeswaran; Santarelli, Xavier

    2016-01-01

    A vast majority of the cardioprotective properties exhibited by High-Density Lipoprotein (HDL) is mediated by its major protein component Apolipoprotein A-I (ApoA1). In order to develop a simplified bioprocess for producing recombinant human Apolipoprotein A-I (rhApoA1) in its near-native form, rhApoA1was expressed without the use of an affinity tag in view of its potential therapeutic applications. Expressed in Pichia pastoris at expression levels of 58.2 mg ApoA1 per litre of culture in a reproducible manner, the target protein was purified by mixed-mode chromatography using Capto™ MMC ligand with a purity and recovery of 84% and 68%, respectively. ApoA1 purification was scaled up to Mixed-mode Expanded Bed Adsorption chromatography to establish an 'on-line' process for the efficient capture of rhApoA1 directly from the P. pastoris expression broth. A polishing step using anion exchange chromatography enabled the recovery of ApoA1 up to 96% purity. Purified ApoA1 was identified and verified by RPLC-ESI-Q-TOF mass spectrometry. This two-step process would reduce processing times and therefore costs in comparison to the twelve-step procedure currently used for recovering rhApoA1 from P. pastoris. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Simultaneous determination of niacin and pyridoxine at trace levels by using diode array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Sel, Sabriye; Öztürk Er, Elif; Bakırdere, Sezgin

    2017-10-26

    A highly sensitive and simple diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method was developed for the simultaneous determination of niacin and pyridoxine in pharmaceutical drugs, tap water and wastewater samples. To determine the in vivo behavior of niacin and pyridoxine, analytes were subjected to simulated gastric conditions. The calibration plots of the diode-array high-performance liquid chromatography and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method showed good linearity over a wide concentration range with close to 1.0 correlation coefficients for both analytes. The limit of detection/limit of quantitation values for liquid chromatography quadrupole time-of-flight tandem mass spectrometry analysis were 1.98/6.59 and 1.3/4.4 μg L-1 for niacin and pyridoxine, respectively, while limit of detection/limit of quantitation values for niacin and pyridoxine in high-performance liquid chromatography analysis were 3.7/12.3 and 5.7/18.9 μg L-1 , respectively. Recovery studies were also performed to show the applicability of the developed methods, and % recovery values ​​were found to be between 90-105% in tap water and 94-97% in wastewater for both analytes. The method was also successfully applied for the qualitative and quantitative determination of niacin and pyridoxine in drug samples. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  8. Determination of rutin in cigarette tobacco, filters, mainstream smoke and burned ash of different branded cigarettes by high performance liquid chromatography

    National Research Council Canada - National Science Library

    Sun, Yinshi; Li, Wei; Wang, Jianhua; Bi, Jianjie; Su, Shudong

    2012-01-01

    ... and anti-protozoal properties. A high performance liquid chromatography method was used to analyze rutin in tobacco and filters, mainstream smoke, and burned ash of ten varieties of cigarettes made in China...

  9. Observation of different ceramide species from crude cellular extracts by normal-phase high-performance liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometry

    NARCIS (Netherlands)

    Pettus, BJ; Bielawska, A; Kroesen, BJ; Moeller, PDR; Szulc, ZM; Hannun, YA; Busman, M

    2003-01-01

    Normal-phase high-performance liquid chromatography (NP-HPLC) coupled to atmospheric pressure chemical ionization mass spectrometry (APCI-MS) allows qualitative analysis of endogenous ceramide and dihydroceramide species from crude lipid extracts utilizing chromatographic methods readily adaptable

  10. EPA Method 8321B (SW-846): Solvent-Extractable Nonvolatile Compounds by High Performance Liquid Chromatography-Thermospray-Mass Spectrometry (HPLC-TS-MS) or Ultraviolet (UV) Detection

    Science.gov (United States)

    Method 8321B describes procedures for preparation and analysis of solid, aqueous liquid, drinking water and wipe samples using high performance liquid chromatography and mass spectrometry for extractable non-volatile compounds.

  11. Analysis of eight capsaicinoids in peppers and pepper-containing foods by high-performance liquid chromatography and liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Kozukue, Nobuyuki; Han, Jae-Sook; Kozukue, Etsuko; Lee, Sin-Jung; Kim, Joung-Ae; Lee, Kap-Rang; Levin, Carol E; Friedman, Mendel

    2005-11-16

    Diverse procedures have been reported for the isolation and analysis of secondary metabolites called capsaicinoids, pungent compounds in the fruit of the Capsicum (Solanaceae) plant. To further improve the usefulness of high-performance liquid chromatography (HPLC), studies were carried out on the analysis of extracts containing up to eight of the following capsaicinoids: capsaicin, dihydrocapsaicin, homocapsaicin-I, homocapsaicin-II, homodihydrocapsaicin-I, homodihydrocapsaicin-II, nonivamide, and nordihydrocapsaicin. HPLC was optimized by defining effects on retention times of (a) the composition of the mobile phase (acetonitrile/0.5% formic acid in H2O), (b) the length of the Inertsil column, and (c) the capacity values (k) of the column packing. Identification was based on retention times and mass spectra of individual peaks. Quantification was based on the UV response at 280 nm in HPLC and recoveries from spiked samples. The method (limit of detection of approximately 15-30 ng) was successfully used to quantify capsaicinoid levels of parts of the pepper fruit (pericarp, placenta, seeds, and in the top, middle, and base parts of whole peppers) in 17 species of peppers and in 23 pepper-containing foods. The results demonstrate the usefulness of the method for the analysis of capsaicinoids ranging from approximately 0.5 to 3600 microg of capsaicin equiv/g of product. The water content of 12 fresh peppers ranged from 80.8 to 92.7%. The described freeze-drying, extraction, and analysis methods should be useful for assessing the distribution of capsaicinoids in the foods and in defining the roles of these biologically active compounds in the plant, the diet, and medicine.

  12. Studies of organic residues from ancient Egyptian mummies using high temperature-gas chromatography-mass spectrometry and sequential thermal desorption-gas chromatography-mass spectrometry and pyrolysis-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Buckley, S A; Stott, A W; Evershed, R P

    1999-04-01

    The techniques of gas chromatography-mass spectrometry (GC-MS) and sequential thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) have been utilised to characterise the constituents of tissue-derived or applied organic material from two Pharaonic Egyptian mummies with a view to identifying embalming practices/substances. The results obtained using TD-GC-MS revealed a series of monocarboxylic acids with the C16:0, C18:1 and C18:0 components dominating in both mummies. The thermal desorption products related to cholesterol, i.e., cholesta-3,5,7-triene and cholesta-3,5-diene (only in Khnum Nakht), were detected in both mummies. Khnum Nakht also contained a number of straight chain alkyl amides (C16-C18) and an alkyl nitrile (C18). Other products included the 2,5-diketopiperazine derivative (DKP) of proline-glycine (pro-gly) which was a major component (7.9%) in Khnum Nakht but only a very minor component in Horemkenesi. Py-GC-MS of samples of both specimens yielded a series of alkene/alkane doublets (Horemkenesi C6-C18, Khnum Nakht C6-C24) which dominated their chromatograms. Series of methyl ketones in the C9-C19 chain length range were also present, with C5-C7 cyclic ketones occurring in Horemkenesi only. These ketones are indicative of covalent bond cleavage, probably of polymerised acyl lipids. Nitrogenous products included nitriles (C9-C18) which were significant in both samples, and amides which were only detected in Khnum Nakht. Also present amongst the pyrolysis products were three steroidal hydrocarbons, cholest-(?)-ene, cholesta-3,5,7-triene and cholesta-3,5-diene. High temperature-GC-MS of trimethylsilylated lipid extracts yielded similar monocarboxylic acids to that obtained using TD-GC-MS, while a series of alpha, omega-dicarboxylic acids and a number of mono- and di-hydroxy carboxylic acids not seen in the thermal desorption or pyrolysis GC-MS analyses were significant

  13. High temperature diaphragm valve-based comprehensive two-dimensional gas chromatography.

    Science.gov (United States)

    Freye, Chris E; Mu, Lan; Synovec, Robert E

    2015-12-11

    A high-temperature diaphragm valve-based comprehensive two-dimensional gas chromatography (GC×GC) instrument is demonstrated which readily allows separations up to 325°C. Previously, diaphragm valve-based GC×GC was limited to 175°C if the valve was mounted in the oven, or limited to 265°C if the valve was faced mounted on the outside of the oven. A new diaphragm valve has been commercially developed, in which the temperature sensitive O-rings that previously limited the separation temperatures have been replaced with Kalrez O-rings, a perfluoroelastomer, allowing for significantly higher temperatures permitting a greater range of volatile and semi-volatile compounds to be readily separated. In the current investigation, a separation temperature up to 325°C is demonstrated with the valve mounted directly in the oven. Since the temperature limit for most commonly used GC columns is at or below 325°C, the scope of diaphragm valve-based GC×GC is now dramatically broadened to encompass a majority of all column stationary phase chemistries. A 44-component mixture of alkanes, alcohols, and polyaromatic hydrocarbons is used to study this new configuration whose boiling points range from 98°C (n-heptane) to 450°C (n-triacontane). For the test mixture using a modulation period PM of 1.0s, peak shapes on second dimension separations, (2)D, are symmetric with average widths at base of 79.4ms, producing a (2)D peak capacity of (2)nc∼12. Based on the average peak width of 2.4s for the first dimension separation with a run time of 32.5min, the (1)D peak capacity is (1)nc∼800. Thus, the ideal two-dimensional peak capacity [Formula: see text] is 9600. Little variation in within-analyte (2)D peak width was observed with an average %RSD of less than 3.0%. Furthermore, retention time on (2)D was very reproducible with an average %RSD less than 0.5%. Measured peak areas (sum of all (2)D peaks for given analyte) had an average %RSD of 4.4%. The transfer fraction from (1)D

  14. Quantification of LSD in illicit samples by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Pablo Alves Marinho

    2010-12-01

    Full Text Available In the present study, a method using high performance liquid chromatography to quantify LSD, in blotter papers seized in Minas Gerais, was optimized and validated. Linearity, precision, recovery, limits of detection and quantification, and selectivity were the parameters used to evaluate performance. The samples were extracted with methanol:water (1: 1 in an ultra-sound bath. The linearity between 0.05 and 20.00 μg/mL (0.5 and 200.0μg of LSD/blotter was observed with satisfactory mean intra and inter assay precision (RSDr = 4.4% and RSD R = 6.4%, respectively and with mean recoveries of 83.4% and 84.9% to the levels of 1.00 and 20.00 μg/mL (10 and 200μg LSD/blotter. The limits of detection and quantification were 0.01 and 0.05 μg/mL, respectively (0.1 and 0.5 μg of LSD/blotter. The samples of blotters (n =22 were analyzed and the mean value of 67.55 μg of LSD/blotter (RSD=27.5% was found. Thus, the method used showed satisfactory analytical performance, and proved suitable as an analytical tool for LSD determination in illicit samples seized by police forces.No presente trabalho, um método utilizando cromatografia líquida de alta eficiência foi otimizado e validado para quantificar o LSD em selos apreendidos em Minas Gerais. A linearidade, precisão, recuperação, limites de detecção e quantificação e seletividade foram os parâmetros de desempenho avaliados. As amostras foram extraídas com metanol: água (1:1 em banho de ultra-som. A linearidade entre 0,05 a 20,00 mg/mL (0,5 a 200 μg LSD/blotter foi observada com precisão média, intra e inter ensaio, satisfatória (RSDr = 4,4% e RSD R = 6,4%, respectivamente e com recuperações médias de 83,4% e 84,9% para os níveis de LSD de 1,00 e 20,00 mg/mL (10 e 200 μg LSD/selo. Os limites de detecção e quantificação encontrados foram de 0,01 e 0,05 mg/mL, respectivamente (0,1 e 0,5 μg LSD/selo. As amostras de selos (n = 22 foram analisadas e o valor médio encontrado foi de 67

  15. High-Performance Liquid Chromatography of Nucleobases, Nucleosides and Nucleotides : II. Mobile Phase Composition for the Separation of Charged Solutes by Ion-Exchange Chromatography

    NARCIS (Netherlands)

    Haastert, Peter J.M. van

    1981-01-01

    The polarity, pH, ion concentration and polarity of the buffer ions of the mobile phase were modified systematically in order to find optimal conditions for the separation of nucleobases, nucleosides and nucleotides by ion-exchange chromatography. The effects of these mobile phase parameters on the

  16. Immunoaffinity chromatography for the sample pretreatment of Taxus plant and cell extracts prior to analysis of taxanes by high-performance liquid chromatography

    NARCIS (Netherlands)

    Theodoridis, G; Haasnoot, W; Schilt, R; Jaziri, M; Diallo, B; Papadoyannis, IN; de Jong, GJ; Cazemier, G.

    2002-01-01

    The application of immunoaffinity chromatography for the purification of Taxus plant and cell extracts prior to the HPLC analysis is described. Polyclonal antibodies raised against 10-deacetylbaccatin III (10-DAB III), paclitaxel's main precursor in plant, were characterised by enzymed-linked

  17. Comparative analysis of native and permethylated human milk oligosaccharides by liquid chromatography coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Oursel, Stéphanie; Cholet, Sophie; Junot, Christophe; Fenaille, François

    2017-12-15

    Human milk oligosaccharides (HMOs) represent the third most abundant components of milk after lactose and lipids. HMOs are indigestible by the suckling infant but can act as prebiotics and have significant biological functions regarding the organism defense against pathogens (such as bacteria or viruses) by preventing interactions with their receptors. Although constituted of only five distinct monosaccharide building blocks, HMOs are highly structurally diverse compounds with many co-existing structural isomers. Here we report the development and comparison of two distinct glycomic platforms based on liquid chromatography coupled to high resolution mass spectrometry (LC-MS) for analyzing HMOs. We have implemented and thoroughly compared the LC-MS of permethylated and native HMOs on reversed phase (RP) and porous graphitic carbon (PGC) columns for their ability to resolve the natural heterogeneity of milk oligosaccharides at the highest sensitivity. Our data essentially underlines the usefulness of analyzing HMOs as permethylated derivatives especially for getting more precise structural information at high sensitivity. For instance, permethylation annihilates gas-phase fucose migration during MS/MS experiments, thus facilitating spectra interpretation and giving access to relevant information regarding oligosaccharide branching and isomer distinction. At the opposite, LC-MS profiling of native HMOs (using PGC) in milk performed best in terms of detected species, while also being much faster in terms of sample preparation. Although less efficient than PGC chromatography, RPLC proved successful for separating pairs of permethylated isomeric HMOs. A key advantage of RP over PGC liquid chromatography is that retention times can be correlated to molecular weights, which can greatly facilitate further HMO identification using retention time prediction. Altogether these data lead us to think that LC-MS analysis of native HMOs (using PGC) can be used as first

  18. Fundamental and practical studies on high-performance liquid affinity chromatography of biopolymers with novel stationary phases

    Energy Technology Data Exchange (ETDEWEB)

    Bacolod, M.D.

    1992-01-01

    Rigid microparticulate stationary phases having surface-bound metal chelating functions were developed and evaluated in high performance metal chelate affinity chromatography of proteins. Silica- and polystyrene-divinylbenzene-based metal chelate sorbents were produced in wide pore and in non-porous type of column packings. A major effort has been placed on development of non-porous highly crosslinked polystyrene-divinylbenzene (PSDVB). These PSDVB microparticles were produced by a two-step swelling polymerization, and exhibited excellent mechanical strength over a wide range of flow-rates and composition used in high performance liquid chromatography (HPLC). Simple and reproducible hydrophilic coatings were developed for the surface modification of hydrophobic PSDVB supports. A tetradentate metal chelating ligand, ethylenediamine-N, N[prime]-diacetic acid (EDDA), was covalently bound to the surface of the various supports. Sorbents having iminodiacetic acid (IDA) metal chelating functions were also evaluated. The hydrophilic character and surface coverage of various stationary phases were assessed chromatographically. Studies concerning the effects of eluent pH as well as the nature and concentration of salts on retention and selectivity with different metal chelate stationary phases having various immobilized metal ions were carried out. Elution schemes were developed for rapid separation of proteins in metal chelate affinity chromatography. EDDA stationary phases in metal forms can be viewed as complementary to IDA stationary phases since they afforded different selectivity and retentivity toward proteins. Hydrophilic PSDVB could be functionalized with IDA or EDDA metal chelating ligands or lectins. The non-porous metal chelate stationary phases afforded rapid separation of proteins by the development of multiple gradient systems, which permitted higher column peak capacity, enabling the separation of a greater number of proteins in a single chromatographic run.

  19. Separation of Highly Complex Mixtures by Two-Dimension Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Georges Guiochon

    2009-12-11

    This report summarizes the progress made on the title project during the grant period. We developed a new classification of two-dimensional separations based on the observation that separations can be made in time or in space. Thus, two-dimensional separations can be made in time×time, space×space, space×time, or time×space. The two successive separations must use two different modes of chromatography that afford uncorrelated or weakly correlated patterns of retention factors for the components of the samples analyzed. Our attention was mainly focused on the separation of protein digests, particularly, on those of the digests of myoglobin and bovine serum albumin as model systems and extremely efficient temporal separations were developed. We also designed and constructed new instruments to carry out space×space separations (True Bidimensional Chromatography, HPLC2 or spacial separations) and time×space separations (a new hybrid combination of a temporal and a spacial separation that we designed).

  20. Enantioseparations by high-performance liquid chromatography based on chiral ligand-exchange.

    Science.gov (United States)

    Natalini, Benedetto; Sardella, Roccaldo; Ianni, Federica

    2013-01-01

    Chiral ligand-exchange chromatography (CLEC) first described in the late 1960s to early 1970s by Davankov and Rogozhin can be still considered as an elective choice for the direct enantioseparation of compounds endowed with chelating moieties. Among the numerous chelating species that have been evaluated as chiral selectors in ligand-exchange (LE) chromatography, a special role is played by a group of amino acids including proline, hydroxyproline, cysteine, phenylalanine, and penicillamine. More to the point, relevant chromatographic performances are also provided by amino alcohol-based chiral selectors, among which, those carrying a leucinol residue as the basic scaffold are worth to be mentioned. Among the various enantiomer chromatographic separation techniques, CLEC has been exploited in all the main techniques including a chiral mobile phase (CMP), a covalently bound chiral stationary phase (B-CSP), and a coated chiral stationary phase (C-CSP). It is the objective of this chapter to describe selected CLEC applications dealing with the above three distinct approaches.

  1. Studying host cell protein interactions with monoclonal antibodies using high throughput protein A chromatography.

    Science.gov (United States)

    Sisodiya, Vikram N; Lequieu, Joshua; Rodriguez, Maricel; McDonald, Paul; Lazzareschi, Kathlyn P

    2012-10-01

    Protein A chromatography is typically used as the initial capture step in the purification of monoclonal antibodies produced in Chinese hamster ovary (CHO) cells. Although exploiting an affinity interaction for purification, the level of host cell proteins in the protein A eluent varies significantly with different feedstocks. Using a batch binding chromatography method, we performed a controlled study to assess host cell protein clearance across both MabSelect Sure and Prosep vA resins. We individually spiked 21 purified antibodies into null cell culture fluid generated with a non-producing cell line, creating mock cell culture fluids for each antibody with an identical composition of host cell proteins and antibody concentration. We demonstrated that antibody-host cell protein interactions are primarily responsible for the variable levels of host cell proteins in the protein A eluent for both resins when antibody is present. Using the additives guanidine HCl and sodium chloride, we demonstrated that antibody-host cell protein interactions may be disrupted, reducing the level of host cell proteins present after purification on both resins. The reduction in the level of host cell proteins differed between antibodies suggesting that the interaction likely varies between individual antibodies but encompasses both an electrostatic and hydrophobic component. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Identification of Ceftiofur Oxidation Products by High-Performance Liquid Chromatography/Electrospray Ionization/Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hye-Sung Cho

    2011-03-01

    Full Text Available Oxidation products of ceftiofur were formed in hydrogen peroxide solution. The structures of the ceftiofur oxidationproducts were characterized by high-performance liquid chromatography/electrospray ionization/tandem mass spectrometry(HPLC/ESI/MS/MS. The products were identified as compounds oxidized at the sulfur of a cephem ring. For further analysis,experiments were performed using O18-labeled hydrogen peroxide. In addition, density-functional calculations were carried out forsix possible oxidation products to support the experimental results.

  3. Investigation into the temporal stability of aqueous standard solutions of psilocin and psilocybin using high performance liquid chromatography.

    Science.gov (United States)

    Anastos, N; Barnett, N W; Pfeffer, F M; Lewis, S W

    2006-01-01

    This paper reports an investigation into the temporal stability of aqueous solutions of psilocin and psilocybin reference drug standards over a period of fourteen days. This study was performed using high performance liquid chromatography utilising a (95:5% v/v) methanol: 10 mM ammonium formate, pH 3.5 mobile phase and absorption detection at 269 nm. It was found that the exclusion of light significantly prolonged the useful life of standards, with aqueous solutions of both psilocin and psilocybin being stable over a period of seven days.

  4. [Ultra-high performance liquid chromatography-mass spectrometry for analysis of newborn and fetal bovine serum components].

    Science.gov (United States)

    Li, Caixia; Wang, Fuke; Liu, Liu

    2014-05-01

    We used ultra-high performance liquid chromatography-mass spectrometry (UPLC/MS) for analyzing and identifying the active components of newborn calf serum (NCS) and fetal bovine serum (FBS). The results demonstrated significant differences in the components between NCS and FBS. FBS appeared to have more complex components than NCS, with mass to ratios (m/z) of the substances of 498, 273 and 448. These substances in FBS may be the main active components to support the proliferation and differentiation of cells.

  5. Isolation and purification of series bioactive components from Hypericum Perforatum L. by high-speed counter-current chromatography

    OpenAIRE

    Cao, Xueli; Wang, Qiaoe; Li, Yan; Bai, Ge; Ren, Hong; Ito, Yiochiro

    2011-01-01

    High-speed counter-current chromatography (HSCCC) combined with pre-separation by ultrasonic solvent extraction was successively used for the separation of series bioactive compounds from the crude extract of Hypericum perforatum L. The petroleum ether extract was separated by the solvent system of n-heptane-methanol-acetonitrile (1.5:0.5:0.5, v/v) and n-heptane-methanol (1.5:1, v/v) in gradient elution, yielding a phloroglucinol compound, hyperforin with HPLC purity over 98%. The ethyl aceta...

  6. Determination of methyldibromoglutaronitrile in cosmetic products by high-performance liquid chromatography with electrochemical detection. Method validation

    DEFF Research Database (Denmark)

    Rastogi, Suresh Chandra; Zachariae, Claus; Johansen, Jeanne D

    2004-01-01

    An increased frequency of contact allergy to methyldibromoglutaronitrile (MDBGN), a commonly used preservative in cosmetics and other consumer products, has been reported in recent years. A high-performance liquid chromatography (HPLC) method for the determination of MDBGN in cosmetic products has...... been validated in the present study. The identification is performed by reductive electrochemical detection of the bromine present in the molecule. The method is suitable for compliance testing of cosmetic products as well as for the research to support clinical and epidemiological studies....

  7. High-performance liquid chromatography on-line coupled to high-field NMR and mass spectrometry for structure elucidation of constituents of Hypericum perforatum L

    DEFF Research Database (Denmark)

    Hansen, S. H.; Jensen, A. G.; Cornett, Claus

    1999-01-01

    The on-line separation and structure elucidation of naphthodianthrones, flavonoids, and other constituents of an extract from Hypericum perforatum L, using high performance liquid chromatography (HPLC) coupled on-line with ultraviolet-visible, nuclear magnetic resonance (NMR), and mass spectrometry......, all of the major known constituents in extracts from Hypericum perforatum L, were identified, and two new substances which had not previously been reported as constituents of extracts of Hypericum perforatum L. were identified and their structures elucidated....

  8. Stability and Degradation of Caffeoylquinic Acids under Different Storage Conditions Studied by High-Performance Liquid Chromatography with Photo Diode Array Detection and High-Performance Liquid Chromatography with Electrospray Ionization Collision-Induced Dissociation Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Meng Xue

    2016-07-01

    Full Text Available Caffeoylquinic acids (CQAs are main constituents in many herbal medicines with various biological and pharmacological effects. However, CQAs will degrade or isomerize when affected by temperature, pH, light, etc. In this study, high-performance liquid chromatography with photodiode array detection (HPLC-PDA and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS was utilized to study the stability and degradation of CQAs (three mono-acyl CQAs and four di-acyl CQAs under various ordinary storage conditions (involving different temperatures, solvents, and light irradiation. The results indicated that the stability of CQAs was mainly affected by temperature and light irradiation, while solvents did not affect it in any obvious way under the conditions studied. Mono-acyl CQAs were generally much more stable than di-acyl CQAs under the same conditions. Meanwhile, the chemical structures of 30 degradation products were also characterized by HPLC-MSn, inferring that isomerization, methylation, and hydrolysis were three major degradation pathways. The result provides a meaningful clue for the storage conditions of CQAs standard substances and samples.

  9. Highly sensitive and selective analysis of widely targeted metabolomics using gas chromatography/triple-quadrupole mass spectrometry.

    Science.gov (United States)

    Tsugawa, Hiroshi; Tsujimoto, Yuki; Sugitate, Kuniyo; Sakui, Norihiro; Nishiumi, Shin; Bamba, Takeshi; Fukusaki, Eiichiro

    2014-01-01

    In metabolomics studies, gas chromatography coupled with time-of-flight or quadrupole mass spectrometry has frequently been used for the non-targeted analysis of hydrophilic metabolites. However, because the analytical platform employs the deconvolution method to extract single-metabolite information from co-eluted peaks and background noise, the extracted peak is artificial product depending on the mathematical parameters and is not completely compatible with the pure component obtained by analyzing a standard compound. Moreover, it has insufficient ability for quantitative metabolomics. Therefore, highly sensitive and selective methods capable of pure peak extraction without any complicated mathematical techniques are needed. For this purpose, we have developed a novel analytical method using gas chromatography coupled with triple-quadrupole mass spectrometry (GC-QqQ/MS). We developed a selected reaction monitoring (SRM) method to analyze the trimethylsilyl derivatives of 110 metabolites, using electron ionization. This methodology enables us to utilize two complementary techniques-non-targeted and widely targeted metabolomics in the same sample preparation protocol, which would facilitate the formulation or verification of novel hypotheses in biological sciences. The GC-QqQ/MS analysis can accurately identify a metabolite using multichannel SRM transitions and intensity ratios in the analysis of living organisms. In addition, our methodology offers a wide dynamic range, high sensitivity, and highly reproducible metabolite profiles, which will contribute to the biomarker discoveries and quality evaluations in biology, medicine, and food sciences. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  10. Analysis of therapeutic proteins and peptides using multiangle light scattering coupled to ultra high performance liquid chromatography.

    Science.gov (United States)

    Espinosa-de la Garza, Carlos E; Miranda-Hernández, Mariana P; Acosta-Flores, Lilia; Pérez, Néstor O; Flores-Ortiz, Luis F; Medina-Rivero, Emilio

    2015-05-01

    Analysis of the physical properties of biotherapeutic proteins is crucial throughout all the stages of their lifecycle. Herein, we used size-exclusion ultra high performance liquid chromatography coupled to multiangle light scattering and refractive index detection systems to determine the molar mass, mass-average molar mass, molar-mass dispersity and hydrodynamic radius of two monoclonal antibodies (rituximab and trastuzumab), a fusion protein (etanercept), and a synthetic copolymer (glatiramer acetate) employed as models. A customized instrument configuration was set to diminish band-broadening effects and enhance sensitivity throughout detectors. The customized configuration showed a performance improvement with respect to the high-performance liquid chromatography standard configuration, as observed by a 3 h column conditioning and a higher resolution analysis in 20 min. Analysis of the two monoclonal antibodies showed averaged values of 148.0 kDa for mass-average molar mass and 5.4 nm for hydrodynamic radius, whereas for etanercept these values were 124.2 kDa and 6.9 nm, respectively. Molar-mass dispersity was 1.000 on average for these proteins. Regarding glatiramer acetate, a molar mass range from 3 to 45 kDa and a molar-mass dispersity of 1.304 were consistent with its intrinsic peptide diversity, and its mass-average molar mass was 10.4 kDa. Overall, this method demonstrated an accurate determination of molar mass, overcoming the difficulties of size-exclusion chromatography. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Determination of total L-Ascorbic Acid by high performance liquid chromatography in human plasma

    Directory of Open Access Journals (Sweden)

    Oveisi MR

    2001-07-01

    Full Text Available The total vitamin C content in human plasma is widely accepted as an indicator of the tissue status of vitamin C. A liquid chromatography method with ultraviolet detector (264 nm for measuring ascorbic acid in human plasma was developed. A C18 reversed-phase column and cetrimide as an ion-pairing agent was employed. Ascorbic acid (AA was measured after reducing L-dehydroascorbic acid to L-ascorbic acid with dithiothreitol. The stability of the ascorbic acid in plasma, metaphosphoric acid and trichloroacetic acid was also evaluated. The analytical parameters, including linearity (1-60 µg/ml, accuracy (98.98%, repeatability (2.8% and reproducibility (7.2%, showed that the method is reliable for measuring the total vitamin C content in plasma.

  12. Frontally eluted components procedure with thin layer chromatography as a mode of sample preparation for high performance liquid chromatography quantitation of acetaminophen in biological matrix.

    Science.gov (United States)

    Klimek-Turek, A; Sikora, M; Rybicki, M; Dzido, T H

    2016-03-04

    A new concept of using thin-layer chromatography to sample preparation for the quantitative determination of solute/s followed by instrumental techniques is presented Thin-layer chromatography (TLC) is used to completely separate acetaminophen and its internal standard from other components (matrix) and to form a single spot/zone containing them at the solvent front position (after the final stage of the thin-layer chromatogram development). The location of the analytes and internal standard in the solvent front zone allows their easy extraction followed by quantitation by HPLC. The exctraction procedure of the solute/s and internal standard can proceed from whole solute frontal zone or its part without lowering in accuracy of quantitative analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Chromatographic behaviour of steroidal saponins studied by high-performance liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Kite, Geoffrey C; Porter, Elaine A; Simmonds, Monique S J

    2007-05-04

    The chromatographic behaviour of steroidal saponins found in Anemarrhena asphodeloides, Asparagus officinalis, Convallaria majalis, Digitalis purpurea and Ruscus aculeatus was studied by HPLC-MS using a C-18 reversed-phase column and aqueous acetonitrile or aqueous methanol mobile phase gradients, with or without the addition of 1% acetic acid. The behaviour was compared to that of triterpene saponins found in Aesculus hippocastanum, Centella asiatica, Panax notoginseng and Potentilla tormentilla. Inclusion of methanol in the mobile phase under acidic conditions was found to cause furostanol saponins hydroxylated at C-22 to chromatograph as broad peaks, whereas the peak shapes of the spirostanol saponins and triterpene saponins studied remained acceptable. In aqueous methanol mobile phases without the addition of acid, furostanol saponins chromatographed with good peak shape, but each C-22 hydroxylated furostanol saponin was accompanied by a second chromatographic peak identified as its C-22 methyl ether. Methanolic extracts analysed in non-acidified aqueous acetonitrile mobile phases also resolved pairs of C-22 hydroxy and C-22 methoxy furostanol saponins. The C-22 methyl ether of deglucoruscoside was found to convert to deglucoruscoside during chromatography in acidified aqueous acetonitrile, or by dissolving in water. Poor chromatography of furostanol saponins in acidified aqueous methanol is due to the interconversion of the C-22 hydroxy and C-22 methoxy forms. It is recommended that initial analysis of saponins by HPLC-MS using a C-18 stationary phase is performed using acidified aqueous acetonitrile mobile phase gradients. The existence of naturally-occurring furostanol saponins methoxylated at C-22 can be investigated with aqueous acetonitrile mobile phases and avoiding methanol in the extraction solvent.

  14. Microwave-Assisted Extraction and Purification of Arctiin and Arctigenin from Fructus Arctii by High-Speed Countercurrent Chromatography.

    Science.gov (United States)

    Lü, Haitao; Sun, Zhaoyun; Shan, Hu; Song, Jiying

    2016-03-01

    An efficient method for the rapid extraction, separation and purification of bioactive lignans, arctiin and arctigenin, from Fructus arctii by microwave-assisted extraction coupled with high-speed countercurrent chromatography was developed. The optimal extraction conditions of arctiin and arctigenin were evaluated by orthogonal array. Arctigenin could be converted from arctiin by hydrochloric acid hydrolysis. The separations were performed at a preparative scale with two-phase solvents composed of ethyl acetate-ethanol-water (5 : 1 : 5, v/v/v) for arctiin, and n-hexane-ethyl acetate-ethanol-water (4 : 4 : 3 : 4, v/v/v/v) for arctigenin. From 500 mg of crude extract sample, 122.3 mg of arctiin and 45.7 mg of arctigenin were obtained with the purity of 98.46 and 96.57%, and the recovery of 94.3 and 81.6%, respectively. Their structures were determined by comparison with the high-performance liquid chromatography retention time of standard substance as well as UV, FT-IR, electrospray ion source (ESI)-MS, (1)H-NMR and (13)C-NMR spectrum. According to the antioxidant activity assay, arctigenin had stronger 1,1-diphenyl-2-picrylhydrazyl free radicals scavenging activity. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Isolation and purification of arctigenin from Fructus Arctii by enzymatic hydrolysis combined with high-speed counter-current chromatography.

    Science.gov (United States)

    Liu, Feng; Xi, Xingjun; Wang, Mei; Fan, Li; Geng, Yanling; Wang, Xiao

    2014-02-01

    Enzymatic hydrolysis pretreatment combined with high-speed counter-current chromatography for the transformation and isolation of arctigenin from Fructus Arctii was successfully developed. In the first step, the extract solution of Fructus Arctii was enzymatic hydrolyzed by β-glucosidase. The optimal hydrolysis conditions were 40°C, pH 5.0, 24 h of hydrolysis time, and 1.25 mg/mL β-glucosidase concentration. Under these conditions, the content of arctigenin was transformed from 2.60 to 12.59 mg/g. In the second step, arctigenin in the hydrolysis products was separated and purified by high-speed counter-current chromatography with a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water (10:25:15:20, v/v), and the fraction was analyzed by HPLC, ESI-MS, and (1)H NMR spectroscopy. Finally, 102 mg of arctigenin with a purity of 98.9% was obtained in a one-step separation from 200 mg of hydrolyzed sample. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Determination of fat-soluble vitamins in vegetable oils through microwave-assisted high-performance liquid chromatography.

    Science.gov (United States)

    Carballo, Silvia; Prats, Soledad; Maestre, Salvador; Todolí, José-Luis

    2015-04-01

    In this manuscript, a study of the effect of microwave radiation on the high-performance liquid chromatography separation of tocopherols and vitamin K1 was conducted. The novelty of the application was the use of a relatively low polarity mobile phase in which the dielectric heating effect was minimized to evaluate the nonthermal effect of the microwave radiation over the separation process. Results obtained show that microwave-assisted high-performance liquid chromatography had a shorter analysis time from 31.5 to 13.3 min when the lowest microwave power was used. Moreover, narrower peaks were obtained; hence the separation was more efficient maintaining or even increasing the resolution between the peaks. This result confirms that the increase in mobile phase temperature is not the only variable for improving the separation process but also other nonthermal processes must intervene. Fluorescence detection demonstrated better signal-to-noise compared to photodiode arrayed detection mainly due to the independent effect of microwave pulses on the baseline noise, but photodiode array detection was finally chosen as it allowed a simultaneous detection of nonfluorescent compounds. Finally, a determination of the content of the vitamin E homologs was carried out in different vegetable oils. Results were coherent with those found in the literature. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Strategy for reduced calibration sets to develop quantitative structure-retention relationships in high-performance liquid chromatography.

    Science.gov (United States)

    Andries, Jan P M; Claessens, Henk A; Heyden, Yvan Vander; Buydens, Lutgarde M C

    2009-10-12

    In high-performance liquid chromatography, quantitative structure-retention relationships (QSRRs) are applied to model the relation between chromatographic retention and quantities derived from molecular structure of analytes. Classically a substantial number of test analytes is used to build QSRR models. This makes their application laborious and time consuming. In this work a strategy is presented to build QSRR models based on selected reduced calibration sets. The analytes in the reduced calibration sets are selected from larger sets of analytes by applying the algorithm of Kennard and Stone on the molecular descriptors used in the QSRR concerned. The strategy was applied on three QSRR models of different complexity, relating logk(w) or logk with either: (i) logP, the n-octanol-water partition coefficient, (ii) calculated quantum chemical indices (QCI), or (iii) descriptors from the linear solvation energy relationship (LSER). Models were developed and validated for 76 reversed-phase high-performance liquid chromatography systems. From the results we can conclude that it is possible to develop logP models suitable for the future prediction of retentions with as few as seven analytes. For the QCI and LSER models we derived the rule that three selected analytes per descriptor are sufficient. Both the dependent variable space, formed by the retention values, and the independent variable space, formed by the descriptors, are covered well by the reduced calibration sets. Finally guidelines to construct small calibration sets are formulated.

  18. Isolation of two bioactive diterpenic acids from Copaifera glycycarpa oleoresin by high-speed counter-current chromatography.

    Science.gov (United States)

    De Souza, P A; Rangel, L P; Oigman, S S; Elias, M M; Ferreira-Pereira, A; De Lucas, N C; Leitão, G G

    2010-01-01

    Phytochemical and biological studies carried out on Copaifera species showed that their oleoresins and isolated compounds have various biological activities. The aims of this work were (i) to analyse the Copaifera oleoresin by gas chromatography-mass spectrometry, (ii) to isolate the diterpenic acids from this oleoresin by high-speed countercurrent chromatography (HSCCC) and (iii) to determine the rhodamine 6G Pdr5p activity of these acids. HSCCC was used for the preparative separation of the diterpenes. Spectroscopic methods were used to establish their identity. The gas chromatogram of the oleoresin showed approximately 30 compounds. The two major ones, kaur-16-en-18-oic and polyalthic acids, were isolated in high purity. Kaur-16-en-18-oic acid exhibited the highest rodomine 6G Pdr5p activity among the tested compounds. HSCCC was shown to be a quick and effective tool in the isolation and purification of diterpenes from Copaifera oleoresin. This is the first report on the use of HSCCC for the fractionation of an oleoresin from Copaifera and the isolation of diterpenes therein. Copyright © 2010 John Wiley & Sons, Ltd.

  19. Isolation and purification of prenylated phenolics from Amorpha fruticosa by high-speed counter-current chromatography.

    Science.gov (United States)

    Chen, Chu; Wu, Yan; Chen, Yang; Du, Leilei

    2015-08-01

    Prenylated phenolics such as amorfrutins are recently identified potent anti-inflammatory and antidiabetic natural products. In this work, high-speed counter-current chromatography was investigated for the isolation and purification of prenylated phenolics from the fruits of Amorpha fruticosa by using a two-phase solvent system composed of n-hexane/ethanol/water (5:4:1, v/v). As a result, 14.2 mg of 5,7-dihydroxy-8-geranylflavanone, 10.7 mg of amorfrutin A and 17.4 mg of amorfrutin B were obtained from 200 mg of n-hexane-soluble crude extract in one step within 250 min. The purities of 5,7-dihydroxy-8-geranylflavanone, amorfrutins A and B were 95.2, 96.7 and 97.1%, respectively, as determined by ultra high performance liquid chromatography. The structural identification was performed by mass spectrometry and (1) H and (13) C NMR spectroscopy. The results indicated that the established method is an efficient and convenient way to purified prenylated phenolics from A. fruticosa extract. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Application of Holistic Liquid Chromatography-High Resolution Mass Spectrometry Based Urinary Metabolomics for Prostate Cancer Detection and Biomarker Discovery.

    Science.gov (United States)

    Zhang, Tong; Watson, David G; Wang, Lijie; Abbas, Muhammad; Murdoch, Laura; Bashford, Lisa; Ahmad, Imran; Lam, Nga-Yee; Ng, Anthony C F; Leung, Hing Y

    2013-01-01

    Human exhibit wide variations in their metabolic profiles because of differences in genetic factors, diet and lifestyle. Therefore in order to detect metabolic differences between individuals robust analytical methods are required. A protocol was produced based on the use of Liquid Chromatography- High Resolution Mass Spectrometry (LC-HRMS) in combination with orthogonal Hydrophilic Interaction (HILIC) and Reversed Phase (RP) liquid chromatography methods for the analysis of the urinary metabolome, which was then evaluated as a diagnostic tool for prostate cancer (a common but highly heterogeneous condition). The LC-HRMS method was found to be robust and exhibited excellent repeatability for retention times (0.9. In addition, using the receiver operator characteristics (ROC) test, the area under curve (AUC) for the combination of the four best characterised biomarker compounds was 0.896. The four biomarker compounds were also found to differ significantly (Pprotocol provides a robust approach with a potentially wide application to metabolite profiling of human biofluids in health and disease.

  1. Application of Holistic Liquid Chromatography-High Resolution Mass Spectrometry Based Urinary Metabolomics for Prostate Cancer Detection and Biomarker Discovery.

    Directory of Open Access Journals (Sweden)

    Tong Zhang

    Full Text Available Human exhibit wide variations in their metabolic profiles because of differences in genetic factors, diet and lifestyle. Therefore in order to detect metabolic differences between individuals robust analytical methods are required. A protocol was produced based on the use of Liquid Chromatography- High Resolution Mass Spectrometry (LC-HRMS in combination with orthogonal Hydrophilic Interaction (HILIC and Reversed Phase (RP liquid chromatography methods for the analysis of the urinary metabolome, which was then evaluated as a diagnostic tool for prostate cancer (a common but highly heterogeneous condition. The LC-HRMS method was found to be robust and exhibited excellent repeatability for retention times (0.9. In addition, using the receiver operator characteristics (ROC test, the area under curve (AUC for the combination of the four best characterised biomarker compounds was 0.896. The four biomarker compounds were also found to differ significantly (P<0.05 between an independent patient cohort and controls. This is the first time such a rigorous test has been applied to this type of model. If validated, the established protocol provides a robust approach with a potentially wide application to metabolite profiling of human biofluids in health and disease.

  2. Separation and purification of four phenolic compounds from persimmon by high-speed counter-current chromatography.

    Science.gov (United States)

    Peng, Jinming; Li, Kaikai; Zhu, Wei; Deng, Xiangyi; Li, Chunmei

    2018-01-01

    An efficient method was established by high-speed counter-current chromatography (HSCCC) for preparation of four phenolic compounds from the depolymerization products of persimmon tannin. Using the two solvent systems of n-hexane/ethyl acetate/water (3:17:20, v/v/v) and ethyl acetate/methanol/water (50:1:50, v/v/v), the preparative isolation was successfully performed by a two-step separation. The yields of one run (150mg crude sample) for gallic acid, methyl gallate, and epigallocatechin-3-gallate-(4β→8, 2β→O→7)-epigallocatechin-3-gallate dimer (A-type EGCG dimer) were 4.7, 44.2 and 5.9mg, respectively. In addition, 4.6mg epicatechin-3-gallate-(4β→8, 2β→O→7)-epicatechin-3-gallate dimer (A-type ECG dimer) was obtained by further preparative high-performance liquid chromatography (prep-HPLC). The purities of these compounds were all above 95.0% and their structures were identified by HPLC/ESI-MS. We found that HSCCC had definite advantages for the preparation of dimeric procyanidins compared with previous methods. Furthermore, it was shown that the four phenolic compounds possessed greater antioxidant activities than Trolox. Copyright © 2017. Published by Elsevier B.V.

  3. [Comparison of the determination results of gentamycin C components by high performance liquid chromatography with different detectors].

    Science.gov (United States)

    Li, Wei; Hu, Changqin; Wang, Mingjuan

    2007-07-01

    The results were compared for determining gentamycin C components by high per-formance liquid chromatography with different detectors in pharmacopoeias. Evaporative light-scattering detector (ELSD) was first used in Pharmacopoeia of People's Republic of China (ChP) 2005, while British Pharmacopoeia (BP) 2005 adopted pulsed amperometric detector in quantitative analysis of gentamycin. As gentamycin C components could not produce signals using UV detector, pre-column derivatization method made the detection possible, referring to United State Pharmacopoeia (USP) 29th Ed, etc. However, the absorbance of by-products and reagents overlapped with gentamycin C components, which caused much trouble in integrating peaks. That is the reason that the quantitative results were calculated based on area and height in different editions of ChP. To make the determination more accurate, "pure" chromatogram was resolved by heuristic evolving latent projection (HELP) method, based on calculating the data obtained with high performance liquid chromatography-diode array detection (HPLC-DAD) using pre-column derivatization with o-phthalic aldehyde (OPA). After subtracting the interference of impurities, gentamycin C1 component in samples was quantitatively determined accurately. The results were comparable to what achieved with HPLC-evaporative light-scattering detector and column switching. At the same time, it was proved that the HPLC-ELSD method in ChP 2005 was more reliable than the pre-column derivatization method.

  4. Identification of chemical components in Baidianling Capsule based on gas chromatography-mass spectrometry and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Wu, Wenying; Chen, Yu; Wang, Binjie; Sun, Xiaoyang; Guo, Ping; Chen, Xiaohui

    2017-08-01

    Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography-mass spectrometry in combination with retention indices and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkynes, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furans, pyrrole, acid amides, heterocycles, and oxides were detected from Baidianling Capsule by gas chromatography-mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index. Then, a total of 124 components were tentatively identified by high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Fifteen constituents from Baidianling Capsule were accurately identified by comparing the retention times with those of reference compounds, others were identified by comparing the retention times and mass spectrometry data, as well as retrieving the reference literature. This study provides a practical strategy for rapidly screening and identifying the multiple constituents of a complex traditional Chinese medicine. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Rapid determination of Papaver somniferum alkaloids in process streams using monolithic column high-performance liquid chromatography with chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Costin, Jason W. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Lewis, Simon W. [Department of Applied Chemistry, Curtin University of Technology, Perth, WA 6845 (Australia); Purcell, Stuart D. [GlaxoSmithKline, Port Fairy, Victoria 3284 (Australia); Waddell, Lucy R. [GlaxoSmithKline, Port Fairy, Victoria 3284 (Australia); Francis, Paul S. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Barnett, Neil W. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia)]. E-mail: barnie@deakin.edu.au

    2007-07-30

    We have combined high-performance liquid chromatography (HPLC) separations using a monolithic column with acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection in a rapid and highly sensitive method to monitor the process of extracting opiate alkaloids from Papaver somniferum. Due to the high flow rates allowed with the monolithic column and the inherent selectivity of the chemiluminescence reactions, the four predominant alkaloids - morphine, codeine, oripavine and thebaine - were determined in less than 2 min. The results obtained with numerous process samples compared favourable with those of the standard HPLC methodology. Limits of detection were 1 x 10{sup -10} M, 5 x 10{sup -10} M, 5 x 10{sup -10} M and 1 x 10{sup -9} M, for morphine, codeine, oripavine and thebaine, respectively.

  6. Sensitive determination of specific radioactivity of positron emission tomography radiopharmaceuticals by radio high-performance liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Nakao, Ryuji; Furutsuka, Kenji; Yamaguchi, Masatoshi; Suzuki, Kazutoshi

    2008-10-01

    A sensitive quality control method is often required in positron emission tomography (PET) radiopharmaceutical analysis due to the high specific radioactivity of synthetic products. The applicability of a radio high-performance liquid chromatography (HPLC) method with fluorescence detection was evaluated for a wide variety of PET radiopharmaceuticals. In 29 different radiopharmaceuticals studied, 20 compounds exhibited native fluorescence. These properties enabled sensitive determination of their chemical masses by direct fluorimetric detection after separation by HPLC. For some substances, detection limits were below nanograms per milliliter level, at least 40 times better than current UV absorbance detection. Sufficient reproducibility and linearity were obtained for the analysis of pharmaceutical fluid. Post-column fluorimetric derivatization was also established for the quantitative determination of FDG and ClDG in [(18)F]FDG samples. These methods could be applied successfully to the analysis of PET radiopharmaceuticals with ultra-high specific radioactivity.

  7. Identification of Ginkgo biloba supplements adulteration using high performance thin layer chromatography and ultra high performance liquid chromatography-diode array detector-quadrupole time of flight-mass spectrometry.

    Science.gov (United States)

    Avula, Bharathi; Sagi, Satyanarayanaraju; Gafner, Stefan; Upton, Roy; Wang, Yan-Hong; Wang, Mei; Khan, Ikhlas A

    2015-10-01

    Ginkgo biloba is one of the most widely sold herbal supplements and medicines in the world. Its popularity stems from having a positive effect on memory and the circulatory system in clinical studies. As ginkgo popularity increased, non-proprietary extracts were introduced claiming to have a similar phytochemical profile as the clinically tested extracts. The standardized commercial extracts of G. biloba leaf used in ginkgo supplements contain not less than 6% sesquiterpene lactones and 24% flavonol glycosides. While sesquiterpene lactones are unique constituents of ginkgo leaf, the flavonol glycosides are found in many other botanical extracts. Being a high value botanical, low quality ginkgo extracts may be subjected to adulteration with flavonoids to meet the requirement of 24% flavonol glycosides. Chemical analysis by ultra high performance liquid chromatography-mass spectrometry revealed that adulteration of ginkgo leaf extracts in many of these products is common, the naturally flavonol glycoside-rich extract being spiked with pure flavonoids or extracts made from another flavonoid-rich material, such as the fruit/flower of Japanese sophora (Styphnolobium japonicum), which also contains the isoflavone genistein. Recently, genistein has been proposed as an analytical marker for the detection of adulteration of ginkgo extracts with S. japonicum. This study confirms that botanically authenticated G. biloba leaf and extracts made therefrom do not contain genistein, and the presence of which even in trace amounts is suggestive of adulteration. In addition to the mass spectrometric approach, a high performance thin layer chromatography method was developed as a fast and economic method for chemical fingerprint analysis of ginkgo samples.

  8. High-Throughput Proteomics Using High Efficiency Multiple-Capillary Liquid Chromatography With On-Line High-Performance ESI FTICR Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yufeng (BATTELLE (PACIFIC NW LAB)); Tolic, Nikola (BATTELLE (PACIFIC NW LAB)); Zhao, Rui (ASSOC WESTERN UNIVERSITY); Pasa Tolic, Ljiljana (BATTELLE (PACIFIC NW LAB)); Li, Lingjun (Illinois Univ Of-Urbana/Champa); Berger, Scott J.(ASSOC WESTERN UNIVERSITY); Harkewicz, Richard (BATTELLE (PACIFIC NW LAB)); Anderson, Gordon A.(BATTELLE (PACIFIC NW LAB)); Belov, Mikhail E.(BATTELLE (PACIFIC NW LAB)); Smith, Richard D.(BATTELLE (PACIFIC NW LAB))

    2000-12-01

    We report on the design and application of a high-efficiency multiple-capillary liquid chromatography (LC) system for high-throughput proteome analysis. The multiple-capillary LC system was operated at the pressure of 10,000 psi using commercial LC pumps to deliver the mobile phase and newly developed passive feedback valves to switch the mobile phase flow and introduce samples. The multiple-capillary LC system was composed of several serially connected dual-capillary column devices. The dual-capillary column approach was designed to eliminate the time delay for regeneration (or equilibrium) of the capillary column after its use under the mobile phase gradient condition (i.e. one capillary column was used in separation and the other was washed using mobile phase A). The serially connected dual-capillary columns and ESI sources were operated independently, and could be used for either''backup'' operation or with other mass spectrometer(s). This high-efficiency multiple-capillary LC system uses switching valves for all operations and is highly amenable to automation. The separations efficiency of dual-capillary column device, optimal capillary dimensions (column length and packed particle size), suitable mobile phases for electrospray, and the capillary re-generation were investigated. A high magnetic field (11.5 tesla) Fourier transform ion cyclotron resonance (FTICR) mass spectrometer was coupled on-line with this high-efficiency multiple-capillary LC system through an electrospray ionization source. The capillary LC provided a peak capacity of {approx}600, and the 2-D capillary LC-FTICR provided a combined resolving power of > 6 x 10 7 polypeptide isotopic distributions. For yeast cellular tryptic digests, > 100,000 polypeptides were typically detected, and {approx}1,000 proteins can be characterized in a single run.

  9. Cobalamin speciation using reversed-phase micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yanes, Enrique G. E-mail: yanes@bhnrc.usda.gov; Miller-Ihli, Nancy J. E-mail: miller-ihli@bhnrc.usda.gov

    2004-06-18

    Micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry was optimized for the determination and separation of a mixture of cobalt containing species. Four cobalamin species (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5'-deoxyadenosylcobalamin) representing the various forms of vitamin B12 as well as the harmful corrinoid analogue cobinamide dicyanide were separated using reversed-phase microcapillary chromatography with columns containing C18 packing material with a 2-{mu}m particle size. Selection of organic solvents for the separation took into consideration compatibility with the inductively coupled plasma mass spectrometer being used for element specific detection. Optimized method conditions included use of a methanol gradient and make-up solution for the nebulizer. Some issues associated with dead volume were overcome by the extension of the gradient program. The total analysis time was 52 min. The column-to-column variability was evaluated and was found to be very reasonable (9% RSD on average), confirming that this method is rugged and that the technology should be easily transferred to other laboratories.

  10. High performance liquid chromatography with mid-infrared detection based on a broadly tunable quantum cascade laser.

    Science.gov (United States)

    Beskers, Timo F; Brandstetter, Markus; Kuligowski, Julia; Quintás, Guillermo; Wilhelm, Manfred; Lendl, Bernhard

    2014-05-07

    This work introduces a tunable mid-infrared (mid-IR) external cavity quantum cascade laser (EC-QCL) as a new molecular specific detector in liquid chromatography. An EC-QCL with a maximum tunability of 200 cm(-1) (1030-1230 cm(-1)) was coupled to isocratic high performance liquid chromatography (HPLC) for the separation of sugars with a cation exchange column (counter ion: Ca(2+)) and distilled water as the mobile phase. Transmission measurements in a 165 μm thick flow cell allowed for on-line coupling and independent quantification of glucose, fructose and sucrose in the concentration range from 5 mg mL(-1) to 100 mg mL(-1) in several beverages. The results obtained with the EC-QCL detector were found to be in good agreement with those obtained using a differential refractive index detector as a reference. The standard deviation of the method for the linear calibration was better than 5 mg mL(-1) for all sugars and reached a minimum of 1.9 mg mL(-1), while the DRI detector reached a minimum of 1 mg mL(-1). Besides the quantification of sugars for which a calibration was performed, also chromatographic peaks of other components could be identified on the basis of their IR absorption spectra. This includes taurine, ethanol, and sorbitol.

  11. [Chromatographic identification and analysis of dextromoramide in the plasma by the method of high performance liquid chromatography].

    Science.gov (United States)

    Misztal, G; Przyborowski, L; Jednacz, T

    1989-01-01

    Dextromoramide and pethidine were separated and identified by thin-layer chromatography on silica gel, using ammonia and methanol (1.5:100) as the mobile phase, after previous extraction with dicthyl ether or with a mixture of n-hexane and isoamyl alcohol (98.5:1.5) from blood alkalized to pH 10.3 Dextromoramide can be revealed on the chromatograms in the amount of 0.5 micrograms and pethidine in the amount of 1 micrograms using the Dragendorff reagent. Reversed-phase TLC proved less sensitive. High-performance liquid chromatography on the column of LiChrosorb RP-18 was applied to the determination of dextromoramide in blood after extraction with diethyl ether, using methanol--phosphate buffer pH 4.5 (95:5) as the mobile phase. The determination range was of 0.5-5.0 micrograms per 2 cm3 of blood plasma (1.26.10(-8)-1.26.10(-7) mole/dm3).

  12. Identification of metabolites of adonifoline, a hepatotoxic pyrrolizidine alkaloid, by liquid chromatography/tandem and high-resolution mass spectrometry.

    Science.gov (United States)

    Xiong, Aizhen; Yang, Li; He, Yuqi; Zhang, Fang; Wang, Jun; Han, Han; Wang, Changhong; Bligh, S W Annie; Wang, Zhengtao

    2009-12-01

    Hepatotoxic pyrrolizidine alkaloid (HPA)-containing plants have always been a threat to human and livestock health worldwide. Adonifoline, a main HPA in Senecio scandens Buch.-Ham. ex D. Don (Qianli guang), was used officially as an infusion in cases of oral and pharyngeal infections in China. In this study in vivo metabolism of adonifoline was studied for the first time by identifying the metabolites of adonifoline present in bile, urine and feces of rats using liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS(n)) (ion trap) as well as liquid chromatography/electrospray ionization high-resolution mass spectrometry (LC/ESI-HRMS) (quadrupole-time of flight). In total 19 metabolites were identified and, among them, retronecine-N-oxides were confirmed by matching their fragmentation patterns with their fully characterized synthetic compounds. These metabolites are all involved in both phase I and phase II metabolic processes and the principal in vivo metabolism pathways of adonifoline were proposed. Copyright 2009 John Wiley & Sons, Ltd.

  13. DEVELOPMENT AND VALIDATION OF THE HIGH PERFORMANCE LIQUID CHROMATOGRAPHY METHOD FOR THE QUANTITATIVE DETERMINATION OF ERYTHROMYCIN IN DERMO-PREPARATIONS.

    Science.gov (United States)

    Hortolomei, Manuela; Ochiuz, Lacramioara; Popovici, Iuliana; Timofte, D; Petrescu, Diana Cezarina; Ghiciuc, Cristina Mihaela

    2015-01-01

    For the analysis of erythromycin (ER) in topical pharmaceutical forms we developed a high performance liquid chromatography dosage method (HPLC) greatly improved over the method formalized by the European Pharmacopoeia 5th ed. The work conditions for using a chromatography column with C18 stationary phase were established as follows: optimal column temperature, 45 degrees C; the mobile phase consisted of a mixture of 0.001 M disodium phosphate solution : acetonitrile in the ratio 20:80, volume of sample injected 20 μL, injection rate 1 mL/min and spectrum was recorded at λ = 200 nm. The method was validated by determining the following parameters: system precision, linearity, limit of detection (LOD), limit of quantification (LOQ) and accuracy. We determined linearity in the concentration range studied, 0.025 to 1.5 mg/mL. The equation of the regression line is: A = 53.7430 x C + 0.00203 with a regression coefficient of 0.9997. The method has LOQ = 0.0196 mg/mL and LOD = 0.005969. The accuracy of the method is appropriate, the ER recovery degree is in the range of 101.27 - 104.99%. The HPLC method with UV detection for the quantitative determination of ER is manageable, responsive, linear, precise and accurate and it can be used for the quantitative analysis of ER in topical pharmaceutical formulations. UV DETECTION.

  14. [High-sensitivity analysis of purines in alcoholic beverages using hydrophilic interaction chromatography coupled with tandem mass spectrometry].

    Science.gov (United States)

    Kakigi, Yasuhiro; Yoshioka, Toshiaki; Nagatomi, Yasushi; Uyama, Atsuo; Mochizuki, Naoki

    2014-01-01

    In this study, we established a high-sensitivity analytical method for purines in alcoholic beverages using hydrophilic interaction chromatography coupled with tandem mass spectrometry. The alcoholic beverages were hydrolyzed with perchloric acid (60%) and subjected to strong cation exchange solid-phase extraction (Bond Elut SCX). The four purine bases (hypoxanthine, adenine, xanthine, guanine) in the extracted solution were separated by hydrophilic interaction chromatography with TSKgel Amide-80 as a separation column, 10 mM ammonium formate (pH 2.0) as mobile phase A, and acetonitrile/100 mM ammonium formate (pH 2.0) (90/10) as mobile phase B. The detection of purine bases was performed by tandem mass spectrometry with ESI. The linearity of this analytical method was not less than 0.996, and the repeatability was not more than 8.4% for each purine base. The recovery was in the range of 60-105%, and the detection limit was not more than 0.005 mg/100 mL. This established method is expected to be useful for quality control and surveillance of purines in alcoholic beverages.

  15. High sensitivity quantitative lipidomics analysis of fatty acids in biological samples by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Quehenberger, Oswald; Armando, Aaron M; Dennis, Edward A

    2011-11-01

    Historically considered to be simple membrane components serving as structural elements and energy storing entities, fatty acids are now increasingly recognized as potent signaling molecules involved in many metabolic processes. Quantitative determination of fatty acids and exploration of fatty acid profiles have become common place in lipid analysis. We present here a reliable and sensitive method for comprehensive analysis of free fatty acids and fatty acid composition of complex lipids in biological material. The separation and quantitation of fatty acids are achieved by capillary gas chromatography. The analytical method uses pentafluorobenzyl bromide derivatization and negative chemical ionization gas chromatography-mass spectrometry. The chromatographic procedure provides base line separation between saturated and unsaturated fatty acids of different chain lengths as well as between most positional isomers. Fatty acids are extracted in the presence of isotope-labeled internal standards for high quantitation accuracy. Mass spectrometer conditions are optimized for broad detection capacity and sensitivity capable of measuring trace amounts of fatty acids in complex biological samples. . Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Assessment of aflatoxin B1 in livestock feed and feed ingredients by high-performance thin layer chromatography

    Directory of Open Access Journals (Sweden)

    Korrapati Kotinagu

    2015-12-01

    Full Text Available Aim: Detection of aflatoxin B1 in Livestock compound Feed and feed ingredients by high-performance thin layer chromatography (HPTLC. Materials and Methods: Chromatography was performed on HPTLC silica gel 60 F 254, aluminum sheets by CAMAG automatic TLC sampler 4, with mobile phase condition chloroform:acetone:water (28:4:0.06. Extraction of aflatoxin B1 from samples was done as per AOAC method and screening and quantification done by HPTLC Scanner 4 under wavelength 366 nm. Results: A total of 97 livestock feed (48 and feed ingredients (49 samples received from different livestock farms and farmers were analyzed for aflatoxin B1of which 29 samples were contaminated, constituting 30%. Out of 48 livestock compound feed samples, aflatoxin B1 could be detected in 16 samples representing 33%, whereas in livestock feed ingredients out of 49 samples, 13 found positive for aflatoxin B1 representing 24.5%. Conclusion: HPTLC assures good recovery, precision, and linearity in the quantitative determination of aflatoxin B1 extracted from Livestock compound feed and feed ingredients. As more number of feed and feed ingredients are contaminated with aflatoxin B1 which causes deleterious effects in both animal and human beings, so there is a need for identifying the source of contamination, executing control measures, enabling better risk assessment techniques, and providing economic benefits.

  17. An improved approach to hydrophilic interaction chromatography of peptides: Salt gradients in the presence of high isocratic acetonitrile concentrations

    Science.gov (United States)

    Mant, Colin T.; Jiang, Ziqing; Boyes, Barry E.; Hodges, Robert S.

    2013-01-01

    Hydrophilic interaction chromatography (HILIC) for separations of peptides has been employed infrequently, particularly considering that this technique was introduced over 20 years ago. The present manuscript describes a radical departure from the traditional HILIC elution approach, where separations are achieved via increasing salt (sodium perchlorate) gradients in the presence of high isocratic concentrations (>80%) of acetonitrile, denoted HILIC/SALT. This initial study compared to reversed-phase chromatography (RPC), HILIC and HILIC/SALT for the separation of mixtures of synthetic peptide standards varying in structure (amphipathic α-helix, random coil), length (10–26 residues), number of positively charged residues (+1 to +11) and hydrophilicity/hydrophobicity. Results showed a marked superiority of the HILIC/SALT approach compared to traditional HILIC and excellent complementarity to RPC for peptide separations. We believe these initial results offer a new dimension to HILIC, enabling it to transform from an occasional HPLC approach for peptide separations to a more generally applicable method. PMID:23332786

  18. Determination of some aldehydes by using solid-phase microextraction and high-performance liquid chromatography with UV detection.

    Science.gov (United States)

    Kumar, Ashwini; Singh, Baldev; Malik, Ashok Kumar; Tiwary, Dhananjay K

    2007-01-01

    A new approach has been developed for the extraction and determination of aldehydes such as veratraldehyde, m-nitrobenzaldehyde, cinnamaldehyde, benzaldehyde, and p-chlorobenzaldehyde by using solid-phase microextraction (SPME) and high-performance liquid chromatography with UV detection (HPLC/UV). The method involves adsorption of the aldehydes on polydimethylsiloxane/divinylbenzene-coated fiber, followed by desorption in the desorption chamber of the SPME-HPLC interface, using acetonitrile-water (70 + 30) as the mobile phase; UV detection was at 254 nm. A good separation of 5 aldehydes was obtained on a C18 column. The detection limits of veratraldehyde, m-nitrobenzaldehyde, cinnamaldehyde, benzaldehyde, and p-chlorobenzaldehyde are 25, 41, 13, 12, and 11 pg/mL, respectively, which are about 100 times better than the detection limits for other SPME methods using gas chromatography. The proposed method was validated by determining benzaldehyde in bitter almonds and cinnamaldehyde in cinnamon bark. The recoveries of the 5 analytes were determined by analysis of spiked drinking water.

  19. Validation of high-performance liquid chromatography (HPLC method for quantitative analysis of histamine in fish and fishery products

    Directory of Open Access Journals (Sweden)

    B.K.K.K. Jinadasa

    2016-12-01

    Full Text Available A high-performance liquid chromatography method is described for quantitative determination and validation of histamine in fish and fishery product samples. Histamine is extracted from fish/fishery products by homogenizing with tri-chloro acetic acid, separated with Amberlite CG-50 resin and C18-ODS Hypersil reversed phase column at ambient temperature (25°C. Linear standard curves with high correlation coefficients were obtained. An isocratic elution program was used; the total elution time was 10 min. The method was validated by assessing the following aspects; specificity, repeatability, reproducibility, linearity, recovery, limits of detection, limit of quantification and uncertainty. The validated parameters are in good agreement with method and it is a useful tool for determining histamine in fish and fishery products.

  20. High-performance liquid chromatography analysis of black currant (Ribes nigrum L.) fruit phenolics grown either conventionally or organically.

    Science.gov (United States)

    Anttonen, Mikko J; Karjalainen, Reijo O

    2006-10-04

    Black currants (Ribes nigrum L.) contain a diverse range of phenolics and possess a high antioxidant activity, which makes them an interesting target for the functional food industry. In this study, phenolic profiles of organically and conventionally grown black currant fruits, collected from commercial farms within a climatically similar area, were compared. Compounds were identified using UV/vis and mass spectroscopy techniques and quantified with high-performance liquid chromatography equipped with UV/vis detection. Several different conjugates of hydroxycinnamic acids, flavonols, and anthocyanins were quantified. Statistically significant differences between farms were found for almost all compounds. Differences between the highest and the lowest measured values of major phenolic compounds of different phenolic classes ranged from 24 to 77%. Principal component analysis quite effectively separated farms from each other but did not cluster them according to cultivation technique. Thus, it was concluded that the biochemical quality of organically grown black currant fruits does not differ from those grown conventionally.

  1. Preparative isolation and purification of xanthohumol from hops (Humulus lupulus L.) by high-speed counter-current chromatography.

    Science.gov (United States)

    Chen, Qi-He; Fu, Ming-Liang; Chen, Miao-Miao; Liu, Jing; Liu, Xiao-Jie; He, Guo-Qing; Pu, Shou-Cheng

    2012-05-01

    Xanthohumol (XN) and related prenylflavonoids are the main bioactive components of hops (Humulus lupulus L.). The current work is to investigate the use of high-speed counter-current chromatography (HSCCC) in search for high isolation of xanthohumol from hops. A solvent system consisted of n-hexane-ethyl acetate-methanol-water at a volume ratio of 5:5:4:3 was employed. The results demonstrated that the constructed method could be well applied for the isolation of xanthohumol from hops extract. After HSCCC isolation procedure, the purity of xanthohumol was over 95% assayed by HPLC and the yield of extraction was 93.60%. The chemical structure identification of xanthohumol was carried out by UV, (1)H NMR and (13)C NMR. The present results demonstrated that xanthohumol could be efficiently obtained using a single HSCCC step from H. lupulus L. extract. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Determination of undecylenic and sorbic acids in cosmetic preparations by high performance liquid chromatography with electrochemical detection.

    Science.gov (United States)

    Bousquet, Ennio; Spadaro, A; Santagati, N A; Scalia, S; Ronsisvalle, G

    2002-11-07

    A highly sensitive and selective method for the determination of sorbic (SA) and undecylenic acid (UA) in cosmetic formulations by a high performance liquid chromatography method with electrochemical detection (ECD) is described. The pre-column derivatizations of SA and UA and the internal standard (cyclohexanoic acid (cHA)) were carried out using 1-(2,5-dihydroxyphenyl)-2-bromoethanone (2,5-DBE) as an electroactive labeling reagent previously synthesized in our lab. The resulting electroactive esters were separated by isocratic elution of a 5 micrometer Hypersil CN column with acetonitrile-acetate buffer eluent. The compounds were detected by a porous graphite electrode set at an oxidation potential of +0.45 V. The analytical method developed in this study is suitable for quality control assays of complex cosmetic formulations containing sorbic and/or UA.

  3. A novel high-throughput method for supported liquid extraction of retinol and alpha-tocopherol from human serum and simultaneous quantitation by liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Hinchliffe, Edward; Rudge, James; Reed, Paul

    2016-07-01

    Measurement of vitamin A (retinol) and E (alpha-tocopherol) in UK clinical laboratories is currently performed exclusively by high-performance liquid chromatography with ultraviolet detection. We investigated whether retinol and alpha-tocopherol could be measured simultaneously by liquid chromatography tandem mass spectrometry. Serum samples (100 μL) were extracted using Isolute + Supported Liquid Extraction plates. Chromatography was performed on a Phenomenex Kinetex Biphenyl 2.6 μm, 50 × 2.1 mm column, and liquid chromatography tandem mass spectrometry on a Waters Acquity TQD. Injection-to-injection time was 4.3 min. The assay was validated according to published guidelines. Patient samples were used to compare liquid chromatography tandem mass spectrometry and high-performance liquid chromatography with ultraviolet detection methods. For retinol and alpha-tocopherol, respectively, the assay was linear up to 6.0 and 80.0 μmol/L, and lower limit of quantification was 0.07 and 0.26 μmol/L. Intra and interassay imprecision were within desirable analytical specifications. Analysis of quality control material aligned to NIST SRM 968e, and relative spiked recovery from human serum, both yielded results within 15% of target values. Method comparison with high-performance liquid chromatography with ultraviolet detection methodology demonstrated a negative bias for retinol and alpha-tocopherol by the liquid chromatography tandem mass spectrometry method. Analysis of United Kingdom National External Quality Assurance Scheme samples yielded mean bias from the target value of +3.0% for retinol and -11.2% for alpha-tocopherol. We have developed a novel, high-throughput method for extraction of retinol and alpha-tocopherol from human serum followed by simultaneous quantitation by liquid chromatography tandem mass spectrometry. The method offers a rapid, sensitive, specific and cost-effective alternative to high-performance liquid chromatography with

  4. Characterization of hexacationic imidazolium ionic liquids as effective and highly stable gas chromatography stationary phases.

    Science.gov (United States)

    González-Álvarez, Jaime; Blanco-Gomis, Domingo; Arias-Abrodo, Pilar; Díaz-Llorente, Daniel; Ríos-Lombardía, Nicolás; Busto, Eduardo; Gotor-Fernández, Vicente; Gutiérrez-Álvarez, María D

    2012-01-01

    Polycationic ionic liquids (ILs) are an attractive class of ILs with great potential applicability as gas chromatography stationary phases. A family of hexacationic imidazolium ILs derived from the cycloalkanol family was chemically first prepared in a straightforward manner and then applied for analytical separation purposes. Four tuneable engineering vectors, namely cation ring size structure, anion nature, spatial disposition of cycloalkanol substituents and O-substitution, were considered as experimental parameters for the design of the desired ionic liquids. A total number of five new phases based on a common benzene core respectively exhibited column efficiencies around to 2500 plates/m, broad operating temperature ranges and also, even more importantly, good thermal stabilities (bleeding temperature between 260 and 365°C), finding variations in the selectivity and analytes elution orders depending on the IL structures. Their solvation characteristics were evaluated using the Abraham solvation parameter model, establishing clear correlations between their cation structure and retention capability with respect to certain analytes. The study of relationships between the ILs structure and solvation parameters gives us an idea of the IL stationary phase to be used for specific separations. Copyright © 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Unifying expression scale for peptide hydrophobicity in proteomic reversed phase high-pressure liquid chromatography experiments.

    Science.gov (United States)

    Grigoryan, Marine; Shamshurin, Dmitry; Spicer, Victor; Krokhin, Oleg V

    2013-11-19

    As an initial step in our efforts to unify the expression of peptide retention times in proteomic liquid chromatography-mass spectrometry (LC-MS) experiments, we aligned the chromatographic properties of a number of peptide retention standards against a collection of peptides commonly observed in proteomic experiments. The standard peptide mixtures and tryptic digests of samples of different origins were separated under the identical chromatographic condition most commonly employed in proteomics: 100 Å C18 sorbent with 0.1% formic acid as an ion-pairing modifier. Following our original approach (Krokhin, O. V.; Spicer, V. Anal. Chem. 2009, 81, 9522-9530) the retention characteristics of these standards and collection of tryptic peptides were mapped into hydrophobicity index (HI) or acetonitrile percentage units. This scale allows for direct visualization of the chromatographic outcome of LC-MS acquisitions, monitors the performance of the gradient LC system, and simplifies method development and interlaboratory data alignment. Wide adoption of this approach would significantly aid understanding the basic principles of gradient peptide RP-HPLC and solidify our collective efforts in acquiring confident peptide retention libraries, a key component in the development of targeted proteomic approaches.

  6. Ionisation in the absence of high voltage using supercritical fluid chromatography: a possible route to increased signal.

    Science.gov (United States)

    Thite, Mohini A; Boughtflower, Robert; Caldwell, Jeff; Hitzel, Laure; Holyoak, Clare; Lane, Stephen J; Oakley, Paul; Pullen, Frank S; Richardson, Stefan; Langley, G John

    2008-11-01

    Supercritical fluid chromatography (SFC) is fast becoming a technique of choice for the analysis of a wide range of compounds and has been found to be complementary to high-performance liquid chromatography (HPLC). The combination of SFC and mass spectrometry (MS) affords a very useful tool in the separation and analysis of compounds. In this study the ionisation of samples in the absence of an applied electrospray voltage has been observed when using SFC/MS, with some compounds showing increased sensitivity when all ionisation source high voltage (HV) is removed. In an attempt to understand the mechanism of ionisation, a series of test compounds were analysed using standard electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI) source configurations and also different API source designs. In both cases, data were acquired with the applied high voltage on (normal conditions) or with the high voltage off, i.e. no voltage spray (novo-spray). The standards were analysed with a range of pressure and modifier percentage conditions. To understand the nature of the ionisation process observed, this was compared with three established liquid-to-gas ionisation mechanisms. These were thermospray (TSP), charge residue model (CRM) of ESI and sonic spray ionisation (SSI). Experiments were undertaken in an attempt to explain this ionisation phenomenon and quantify any observed change in sensitivity. The most important point to note is that enhanced ionisation was observed under novo-spray conditions in a SFC/MS configuration, which in certain cases provides a lowering in the overall limit of detection (LOD).

  7. Detection and identification of heme c-modified peptides by histidine affinity chromatography, high-performance liquid chromatography-mass spectrometry, and database searching.

    Science.gov (United States)

    Merkley, Eric D; Anderson, Brian J; Park, Jea; Belchik, Sara M; Shi, Liang; Monroe, Matthew E; Smith, Richard D; Lipton, Mary S

    2012-12-07

    Multiheme c-type cytochromes (proteins with covalently attached heme c moieties) play important roles in extracellular metal respiration in dissimilatory metal-reducing bacteria. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) characterization of c-type cytochromes is hindered by the presence of multiple heme groups, since the heme c modified peptides are typically not observed or, if observed, not identified. Using a recently reported histidine affinity chromatography (HAC) procedure, we enriched heme c tryptic peptides from purified bovine heart cytochrome c, two bacterial decaheme cytochromes, and subjected these samples to LC-MS/MS analysis. Enriched bovine cytochrome c samples yielded 3- to 6-fold more confident peptide-spectrum matches to heme c containing peptides than unenriched digests. In unenriched digests of the decaheme cytochrome MtoA from Sideroxydans lithotrophicus ES-1, heme c peptides for 4 of the 10 expected sites were observed by LC-MS/MS; following HAC fractionation, peptides covering 9 out of 10 sites were obtained. Heme c peptide spiked into E. coli lysates at mass ratios as low as 1×10(-4) was detected with good signal-to-noise after HAC and LC-MS/MS analysis. In addition to HAC, we have developed a proteomics database search strategy that takes into account the unique physicochemical properties of heme c peptides. The results suggest that accounting for the double thioether link between heme c and peptide, and the use of the labile heme fragment as a reporter ion, can improve database searching results. The combination of affinity chromatography and heme-specific informatics yielded increases in the number of peptide-spectrum matches of 20-100-fold for bovine cytochrome c.

  8. Purification of Phenylalkanoids and monoterpene glycosides from Rhodiola rosea L. roots by high-speed counter-current chromatography.

    Science.gov (United States)

    Mudge, Elizabeth; Lopes-Lutz, Daise; Brown, Paula N; Schieber, Andreas

    2013-02-01

    Rhodiola rosea L. is a medicinal herb used for its adaptogenic properties. The main active components are the phenylpropanoids collectively referred to as rosavins. To develop an isolation method for phytochemicals present in Rhodiola rosea roots using high-speed counter-current chromatography (HSCCC). The roots of Rhodiola rosea were extracted with methanol and fractionated using liquid-liquid partition and polyamide column clean-up. The purified fraction (100 mg) was subjected to semi-preparative HSCCC using the two-phase solvent system ethyl acetate:butanol:water (3:2:5). The head-to-tail elution mode was employed with a flow rate of 1.5 mL/min and a rotary speed of 1000 rpm. The separation yielded six main fractions with four components more than 90% pure. The sixth fraction was further purified using semi-preparative HPLC with a Synergi-hydro RP C₁₈ -column to obtain rosin and geranyl 1-O-α-l-arabinopyranosyl(1 → 6)-β-d-glucopyranoside. The main components isolated were rosavin (3.4 mg, 97% purity), salidroside (0.5 mg, 90% purity), benzyl-O-β-d-glucopyranoside (1.2 mg, 85% purity), rosarin (1.3 mg, 99% purity), rosiridin (1.8 mg, 92% purity), rosin (1.2 mg, 95% purity) and geranyl 1-O-α-l-arabinopyranosyl(1 → 6)-β-d-glucopyranoside (6.5 mg, 97% purity). The identity and purity of these components were confirmed using ultrafast liquid chromatography-diode-array detector-MS/MS analysis,  ¹H- and ¹³C-NMR spectroscopy. High-speed counter-current chromatography was successful in the isolation of several phytochemicals present in Rhodiola rosea roots, including two components that are not commercially available. Copyright © 2012 John Wiley & Sons, Ltd.

  9. Isolation and purification of orientin and vitexin from Trollius chinensis Bunge by high-speed counter-current chromatography.

    Science.gov (United States)

    Yu, Xiao-Xue; Huang, Jie-Yun; Xu, Dan; Xie, Zhi-Yong; Xie, Zhi-Sheng; Xu, Xin-Jun

    2014-01-01

    Orientin and vitexin are the two main bioactive compounds in Trollius chinensis Bunge. In this study, a rapid method was established for the isolation and purification of orientin and vitexin from T. chinensis Bunge using high-speed counter-current chromatography in one step, with a solvent system of ethyl acetate-ethanol-water (4:1:5, v/v/v). A total of 9.8 mg orientin and 2.1 mg vitexin were obtained from 100 mg of the ethyl acetate extract, with purities of 99.2% and 96.0%, respectively. Their structures were identified by UV, MS and NMR. The method was efficient and convenient, which could be used for the preparative separation of orientin and vitexin from T. chinensis Bunge.

  10. [Analysis of surface-active substances in Sapindus mukurossi by high performance liquid chromatography-mass spectrometry].

    Science.gov (United States)

    Wang, X C

    2001-11-01

    A high performance liquid chromatography-atmospheric pressure ionization mass spectrometry method has been developed for the analysis of surface-active substances (hederagenin saponins and sesquiterpene oligoglycosides) in the extracts of the pericarp of Sapindus mukurossi. The method consists of the separation of surface-active substances using C18 HPLC column, followed by detection using a diode-array detector at 210 nm and then on-line mass spectrometry. Hederagenin saponins and sesquiterpene oligoglycosides were characterized as [M - H]- or [M + Na]+. Based on the relative molecular mass, established by mass spectrometry and the structure induced by in-source CID technology, three components that had not been reported in Sapindus mukurossi before were identified. Several surface-active substances were obtained by means of semi-preparative HPLC. Their structures were further confirmed by NMR spectrometry as mukurozi-saponin Y2, mukurozi-saponin X, mukurozioside I a and mukurozioside II a.

  11. [Determination of serotonin in rat brain microdialysate after i. p. administration of fluoxetine hydrochloride by high performance liquid chromatography].

    Science.gov (United States)

    Guo, Yunzhen; Yu, Li; Ma, Zheng; Guo, Xingjie

    2007-03-01

    The concentration of serotonin (5-HT) in rat brain microdialysate before and after i. p. administration of fluoxetine hydrochloride was determined through precolumn derivatization by reversed-phase high performance liquid chromatography (RP-HPLC). A baseline separation of serotonin was achieved on a Hypersil C18 column (250 mm x 2. 0 mm, 5 microm) with acetonitrile-20 mmol/L sodium acetic solution (pH 5. 0) (45: 55, v/v) containing 20 mmol/L of sodium octanesulfonate as the mobile phase. Fluorescence detection with the excitation wavelength at 330 nm and emission wavelength at 455 nm was used for serotonin. There was good linear relationship between the peak area and concentration in the range of 0. 25 - 5. 0 nmol/L( r =0. 999 1). The limit of quantitation was 0. 25 nmol/L. The method is simple, accurate and can be applied to the determination of serotonin in biological specimen.

  12. Determination of Thiophanate-methyl in Tamoto by High Performance Liquid Chromatography-triple Quadrupole Tandem Mass Spectometry

    Directory of Open Access Journals (Sweden)

    XU Wei-feng

    2014-06-01

    Full Text Available To evaluate the safety of use of 70% thiophanate-methyl wettable powders in tomato, a supervised trial experiment was conducted to study the residues in tomato. A method of determining thiophanate-methyl by high performance liquid chromatography-tandem mass spectrometry(LC-MSMSwas established. Acetonitrile was used as an extraction solvent, and PSA and anhydrous magnesium were used for sample purifying. Samples were determined and quantified by LC-MSMS in the multiple reaction monitoring mode(MRM. The field trial recommended spraying 70% thiophanate-methyl WP on tomato with 562.5 gai· hm-2 in three times, which the safe interval was not less than three days from the last time to harvest. The results showed that the thiophanate methyl residue in tomato was lower than 0.05 mg· kg -1, both from field trials and market sampling samples.

  13. Determination of itopride hydrochloride by high-performance liquid chromatography with Ru(bpy)3(2+) electrogenerated chemiluminescence detection.

    Science.gov (United States)

    Sun, Yonghua; Zhang, Zhujun; Xi, Zhijun; Shi, Zuolong; Tian, Wei

    2009-08-26

    In this work, a stable electrogenerated chemiluminescence (ECL) detector was developed. The detector was prepared by packing cation-exchanged resin particles in a glass tube, followed by inserting Pt wires (working electrode) in this tube and sealing. The leakage of Ru(bpy)(3)(2+) can be compensated by adding a small amount of Ru(bpy)(3)(2+) into solution phase. Coupled with high-performance liquid chromatography separation, the detector has been used for determination of itopride hydrochloride in human serum. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of itopride hydrochloride in the range of 1.0 x 10(-8) g mL(-1) to 1.0 x 10(-6) g mL(-1) and the detection limit was 3 x 10(-9) g mL(-1) (S/N=3). The as-prepared ECL detector displayed good sensitivity and stability.

  14. High-performance liquid chromatography analysis methods developed for quantifying enzymatic esterification of flavonoids in ionic liquids

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, X.B.

    2008-01-01

    Methods using reversed-phase high-performance liquid chromatography (RP-HPLC) with ELSD were investigated to quantify enzymatic reactions of flavonoids with fatty acids in the presence of diverse room temperature ionic liquids (RTILs). A buffered salt (preferably triethylamine-acetate) was found...... essential for separation of flavonoids from strongly polar RTILs, whereby RTILs were generally visible as two major peaks identified based on an ion-pairing/exchanging hypothesis. C8 and C12 stationary phases were optimal while mobile phase pH (3-7) had only a minor influence on separation. The method...... developed was successfully applied for primary screening of RTILs (> 20), with in depth evaluation of substrates in 10 RTILs, for their evaluation as reaction media....

  15. Simultaneous high-performance liquid chromatography assay of acetylsalicylic acid and salicylic acid in film-coated aspirin tablets.

    Science.gov (United States)

    Fogel, J; Epstein, P; Chen, P

    1984-12-28

    A reversed-phase high-performance liquid chromatography (HPLC) method has been developed for the simultaneous assay of acetylsalicylic acid (I) and salicylic acid (II) in film-coated aspirin tablets. As little as 0.1% II (relative to I) can be quantitatively determined. Using a 5-microns octadecylsilane column with water-acetonitrile-phosphoric acid (76:24:0.5) as the mobile phase enabled the chromatographic separation to be completed in 4 min. Due to the slow rate of decomposition of I to II in the extraction solvent, acetonitrile-methanol-phosphoric acid (92:8:0.5), the analysis of many samples was routinely performed by means of automated HPLC equipment. Other compounds (non-aspirin salicylates, caffeine and acetaminophen) were also separated by the chromatographic system.

  16. Reverse-Phase High-Performance Liquid Chromatography (HPLC) Analysis of Retinol and Retinyl Esters in Mouse Serum and Tissues

    Science.gov (United States)

    Kim, Youn-Kyung; Quadro, Loredana

    2013-01-01

    The ability to measure endogenous metabolites of retinoids (vitamin A and its derivatives) in biological samples is key to understanding the crucial physiological actions of vitamin A. Over the years, many assays and methods have been developed to analyze different retinoids in biological samples. Liquid chromatography is the best analytical technique for routine analysis of these compounds. However, due to their different chemical properties, different retinoid metabolites cannot be accurately separated and quantified in a single chromatographic run. Here, we will describe a reverse-phase HPLC isocratic method that enables extraction, separation, identification, and quantification of all-trans-retinol and different molecular species of retinyl ester with high accuracy, sensitivity, and reliability. PMID:20552434

  17. Reverse-phase high-performance liquid chromatography (HPLC) analysis of retinol and retinyl esters in mouse serum and tissues.

    Science.gov (United States)

    Kim, Youn-Kyung; Quadro, Loredana

    2010-01-01

    The ability to measure endogenous metabolites of retinoids (vitamin A and its derivatives) in biological samples is key to understanding the crucial physiological actions of vitamin A. Over the years, many assays and methods have been developed to analyze different retinoids in biological samples. Liquid chromatography is the best analytical technique for routine analysis of these compounds. However, due to their different chemical properties, different retinoid metabolites cannot be accurately separated and quantified in a single chromatographic run. Here, we will describe a reverse-phase HPLC isocratic method that enables extraction, separation, identification, and quantification of all-trans-retinol and different molecular species of retinyl ester with high accuracy, sensitivity, and reliability.

  18. Rapid determination of alpha tocopherol in olive oil adulterated with sunflower oil by reversed phase high-performance liquid chromatography.

    Science.gov (United States)

    Bakre, S M; Gadmale, D K; Toche, R B; Gaikwad, V B

    2015-05-01

    A new method is developed to determine the presence of sunflower oil in olive oil. α-tocopherol is selected as discriminating parameter for detecting sunflower oil adulterant in olive oil. Admixtures of olive oil and sunflower oil (5 %, 10 %, 15 % and 20 % sunflower oil in olive oil) are prepared. These admixtures are analysed by reversed phase high pressure liquid chromatography coupled with fluorescence detector. The sample preparation does not require saponification or addition of antioxidant. The chromatographic system consists of a C18 column with methanol: acetonitrile (50:50) mobile phase. Fluorescence detector excitation wavelength is set at 290 nm and emission wavelength is set at 330 nm. The α tocopherol concentration increases linearly in olive oil adulterated with sunflower oil. The method is simple, selective, sensitive and is precise (RSD = 2.65 %) for α tocopherol. The present method can precisely detect 5 % sunflower oil in olive oil.

  19. Application of high-performance liquid chromatography to the characterization of the betalain pigments in prickly pear fruits.

    Science.gov (United States)

    Fernández-López, J A; Almela, L

    2001-04-13

    The qualitative and quantitative betalain pigment content of two cultivars of prickly pear (Opuntia ficus-indica) fruits grown in southeastern Spain was evaluated. After methanolic extraction of crushed fruits, reversed-phase high-performance liquid chromatography and photodiode array detection were applied simultaneously for the separation, identification and quantification of these pigments. Two main pigments were obtained, which were identified as indicaxanthin (lambda(max) 484 nm) and betanin (lambda(max) 535 nm). Spectrophotometric evaluation of both pigments showed a yield of around 20-30 mg per 100 g of fresh pulp. When the influence of temperature (25 to 90 degrees C) on betacyanin pigment stability was investigated, the results revealed a substantial degree of thermodegradation at temperatures higher than 70 degrees C.

  20. Determination of the triglyceride composition of avocado oil by high-performance liquid chromatography using a light-scattering detector.

    Science.gov (United States)

    Hierro, M T; Tomás, M C; Fernández-Martín, F; Santa-María, G

    1992-08-28

    The triglyceride composition of avocado oil was determined by high-performance liquid chromatography using a light-scattering detector. Two avocado varieties, Fuerte and Hass, were analysed, and the qualitative composition of each was found to be similar, though quantitative differences were detected. The triglyceride composition was predicted using a system of equations based on the relationship between log k' and the molecular variables equivalent carbon number, chain length and number of double bonds for each of the fatty acids in the glycerides. A total of 24 molecular species of triglycerides were identified. The chromatographic system used successfully separated the critical pairs OOO-LOS, PaPaO-LnPP and PaOO-LOP (O = olein; L = linolein; S = stearin; Pa = palmitolein; Ln = linolenin; P = palmitin). Detector response was found to have a linear relationship with the amount of sample injected over the injection range 10-70 micrograms.

  1. Determination of levamisole and tetramisole in seized cocaine samples by enantioselective high-performance liquid chromatography and circular dichroism detection.

    Science.gov (United States)

    Bertucci, Carlo; Tedesco, Daniele; Fabini, Edoardo; Di Pietra, Anna Maria; Rossi, Francesca; Garagnani, Marco; Del Borrello, Elia; Andrisano, Vincenza

    2014-10-10

    Levamisole, an anthelmintic drug, has been increasingly employed as an adulterant of illicit street cocaine over the last decade; recently, the use of tetramisole, the racemic mixture of levamisole and its enantiomer dexamisole, was also occasionally observed. A new enantioselective high-performance liquid chromatography (HPLC) method, performed on cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phases in normal-phase mode, was validated to determine the enantiomeric composition of tetramisole enantiomers in seized cocaine samples. Furthermore, the hyphenation of the validated HPLC method with a circular dichroism (CD) detection system allowed the direct determination of elution order and a selective monitoring of levamisole and dexamisole in the presence of possible interferences. The method was applied to the identification and quantitation of the two enantiomers of tetramisole in seized street cocaine samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Preliminary validation of high performance liquid chromatography method for detection of methyl-testosterone residue in carp muscle

    Science.gov (United States)

    Jiang, Jie; Lin, Hong; Fu, Xiaoting; Li, Mingming

    2005-07-01

    The use of synthetic anabolic steroid methyltestosterone (MT) as growth promoter is prohibited in China. Validations of analytical methods for MT residue in food and the results obtained have become indispensable. The high performance liquid chromatography (HPLC) method for the detection of MT with liquid-liquid extraction by trichloromethane-methanol in carp muscle tissue was preliminarily validated with reference to the following parameters: recovery (accuracy) at the 1, 5 and l0 mgkg-1 level, between-run and within-run CV values (repeatability, also called relative standard deviation (RSD)) and limit of detection. The recoveries were above 80% and the between-run and within-run CV values below 10% for muscle tissue. The limit of detection was 0.05 mgkg-1.

  3. IDENTIFICATION OF MYCOBACTERIUM GENAVENSE IN A DIANA MONKEY (CERCOPITHECUS DIANA) BY POLYMERASE CHAIN REACTION AND HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY.

    Science.gov (United States)

    Kelly, Kathleen M; Wack, Allison N; Bradway, Dan; Simons, Brian W; Bronson, Ellen; Osterhout, Gerard; Parrish, Nicole M; Montali, Richard J

    2015-06-01

    A 25-yr-old Diana monkey (Cercopithecus diana) with a 1.5-yr history of chronic colitis and diarrhea was found to have disseminated granulomatous disease with intralesional acid fast bacilli. Bacilli were identified as Mycobacterium genavense by polymerase chain reaction, sequencing of the 16S-23S ribosomal RNA intergenic spacer (ITS) gene, and mycolic acid analysis by high-performance liquid chromatography. Mycobacterium genavense is a common cause of mycobacteriosis in free-ranging and captive birds. In addition, recognition of opportunistic infection in human immunodeficiency virus-positive patients is increasing. Disease manifestations of M. genavense are similar to Mycobacterium avium complex (MAC) and include fever, wasting, and diarrhea with disseminated disease. Similar clinical signs and lesions were observed in this monkey. Mycobacterium genavense should be considered as a differential for disseminated mycobacterial disease in nonhuman primates as this agent can mimic MAC and related mycobacteria.

  4. Simultaneous determination of eight major bioactive compounds in Dachengqi Tang (DT by high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Chen Guanyuan

    2008-04-01

    Full Text Available Abstract Background Dachengqi Tang (DT is a common traditional Chinese medicine formula for expelling neire ('internal heat' in the stomach and intestines. There was no reliable analytical method available for the quality control of DT. Methods A high-performance liquid chromatography (HPLC method with a reverse phase C18 column (150 × 4.6 mm was developed. The mobile phase was methanol with 0.2% acetic acid. Eight markers including naringin, hesperidin, aloe emodin, rhein, honokiol, magnolol, emodin and chrysophanol were determined. Results Regression analysis revealed a linear relationship between the concentrations of the markers and the peak area ratio of the standards and internal standard. The limit of detection (S/N = 3 and the limit of qualification (RSD Conclusion A reliable HPLC method for simultaneous determination of the eight markers in DT was developed.

  5. Characterisation of tryptic peptides of phosphorylated tyrosine hydroxylase by high-pressure liquid chromatography electrospray ionisation mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Mark E. [Molecular Structure and Detection Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308 (Australia); Dickson, Phillip W. [School of Biomedical Science, University of Newcastle, Callaghan, NSW 2308 (Australia); Dunkley, Peter R. [School of Biomedical Science, University of Newcastle, Callaghan, NSW 2308 (Australia); Nagy-Felsobuki, Ellak I. von [Molecular Structure and Detection Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308 (Australia)]. E-mail: ellak@newcastle.edu.au

    2005-03-01

    Tyrosine hydroxylase (TH) is involved in the biosynthesis of catecholamines and is activated by phosphorylation. Phosphorylated TH was analysed using high-pressure liquid chromatography combined with electrospray mass spectrometry (HPLC ESI-MS). Two mass scanning methods were used to detect tryptic cleavage products of TH. In the positive electrospray ionisation mode (ESI+), the peptides that contain the phosphorylation sites of TH were identified. In the alternative method, a phosphopeptide was detected in the negative electrospray ionisation mode (ESI-) using single ion monitoring in combination with a sequential ESI+ switching experiment. A raised baseline interfered with detection of hydrophilic peptides in ESI-, with the signal-to-noise ratio indicating that the method was operating near the limit of detection for a conventional electrospray source. The switching method improved the certainty of identification of phosphopeptides.

  6. The isolation and purification of glucoraphanin from broccoli seeds by solid phase extraction and preparative high performance liquid chromatography.

    Science.gov (United States)

    Rochfort, Simone; Caridi, Domenico; Stinton, Melanie; Trenerry, V Craige; Jones, Rod

    2006-07-07

    Plant foods contain not only essential nutrients, e.g. protein, amino acids, vitamins and minerals, but also phytochemicals that have added health benefits. One such class of phytochemicals are the glucosinolates. Glucosinolates, particularly glucoraphanin, are predominant in plants of the Brassica genus, most notably in vegetables such as broccoli. There is a growing interest in the role glucoraphanin plays in chemoprotection and as a result there is a requirement to accurately determine the levels of glucoraphanin in vegetable products. Reverse phase ion pair high performance liquid chromatography (HPLC) is the method of choice; however, this work has been hindered by the lack of available standard reference materials. Broccoli seeds, which are particularly rich in glucoraphanin (20-50 mg/g), have proved to be ideal for the isolation of glucoraphanin on the preparative scale. A novel preparative scale HPLC method with simple compound recovery has been developed to meet the need for a glucoraphanin standard.

  7. Analysis of native human plasma proteins and haemoglobin for the presence of bityrosine by high-performance liquid chromatography

    DEFF Research Database (Denmark)

    Daneshvar, B; Frandsen, H; Dragsted, L O

    1997-01-01

    fluorescent substance, bityrosine. High-performance liquid chromatography (HPLC) analysis of acid hydrolyzed serum albumin after oxidation with peroxidase/H2O2 or with Cu++/H2O2 showed that bityrosine had been formed whereas oxidation of this protein with Fe(III)/ascorbate did not result in the formation......Generation of reactive oxygen species in vivo results in oxidative-damage to cellular components, including proteins. Due to the relatively long half-lives of several blood proteins the cumulative formation of oxidatively damaged proteins might serve as a biomarker for reactive oxygen species...... of bityrosine. Bityrosine could not be detected in human plasma proteins or haemoglobin with the detection limit of one pmol per mg protein....

  8. REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY STUDY OF LIPOPHILICITY OF IMIDAZO[2,1-F]THEOPHYLLINE DERIVATIVES.

    Science.gov (United States)

    Zagórska, Agnieszka; Czopek, Anna; Pełka, Karolina; Bajda, Marek; Stanisz-Wallis, Krystyna; Pawłowski, Maciej

    2015-01-01

    The present study is a part of our physicochemical and pharmacological studies in a group of tricyclic theophylline derivatives. The investigated compounds exhibit different pharmacological profiles in comparison to theophylline and have been tested as potential antidepressant and/or antipsychotic agents. The differences in pharmacological action between theophylline and their tricyclic derivatives can be explained by their various physicochemical properties, especially lipophilicity. The chromatographic behavior of twenty three derivatives of imidazo[2,1-ƒ]theophylline was investigated, using reversed-phase high performance liquid chromatography (RP-HPLC) method. Moreover, partition coefficients and selected pharmacokinetic parameters were calculated computationally. Principal component analysis (PCA) method was used to establish the relationship between obtained experimental and computational parameters.

  9. L-ascorbic acid losses in Kenyan vegetables during cooking as determined by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    N.M.N. Wekesa

    2001-06-01

    Full Text Available The loss of L-ascorbic acid (L-AA in 14 different cooked local vegetables found in Nairobi markets was determined by high performance liquid chromatography. The effect of quantity of water on the loss of L-AA during cooking was studied with cowpea leaves. It was found that more L-AA was lost when larger amount of water was used than when smaller amount was used. The effect of the sharpness of the knife on the loss of L-AA was studied with spinach. It was found that more loss of L-AA occurred when a blunt (edge thickness 0.08 cm knife was used for cutting the vegetables than when a sharp knife (edge thickness 0.04 cm was used during cooking. L-AA was also determined when vegetables were cooked in different size pieces (surface are >1 cm2

  10. Bromfenac ophthalmic solution 0.09 %: human aqueous humor concentration detected by high-performance liquid chromatography.

    Science.gov (United States)

    Macrì, Angelo; Vagge, Aldo; Salis, Annalisa; Fucile, Carmen; Marini, Valeria; Martelli, Antonietta; Giuffrida, Sebastiano; Iester, Michele; Damonte, Gianluca; Mattioli, Francesca

    2017-04-01

    The purpose of this study was to evaluate the aqueous humor concentrations of bromfenac ophthalmic solution 0.09 % in patients undergoing phacoemulsification. Patients requiring cataract extraction received one drop (50 µL) of bromfenac 0.09 % solution in the eye to be operated, before bedtime the day before surgery or the morning of the surgery. The last administration was recorded. At the time of paracentesis, an aqueous humor sample was collected with a 30-gauge needle attached to a TB syringe and was later analyzed by high-performance liquid chromatography for drug concentration. 188 treated volunteers and 48 control, untreated, subjects were included in the study. The mean aqueous concentration of bromfenac in the treated group was 37.60 ± 68.86 and 0 nM (nmol/L) in the control group (p humor up to about 12 h after instillation.

  11. [Separation and identification of bovine lactoferricin by high performance liquid chromatography-matrix-assisted laser desorption/ionization time of flight/ time of flight mass spectrometry].

    Science.gov (United States)

    An, Meichen; Liu, Ning

    2010-02-01

    A high performance liquid chromatography-matrix-assisted laser desorption/ionization time of flight/time of flight mass spectrometry (HPLC-MALDI-TOF/TOF MS) method was developed for the separation and identification of bovine lactoferricin (LfcinB). Bovine lactoferrin was hydrolyzed by pepsin and then separated by ion exchange chromatography and reversed-phase liquid chromatography (RP-LC). The antibacterial activities of the fractions from RP-LC separation were determined and the protein concentration of the fraction with the highest activity was measured, whose sequence was indentified by MALDI-TOF/TOF MS. The relative molecular mass of LfcinB was 3 124.89 and the protein concentration was 18.20 microg/mL. The method of producing LfcinB proposed in this study has fast speed, high accuracy and high resolution.

  12. Determination of gouty arthritis' biomarkers in human urine using reversed-phase high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Lei-Wen Xiang

    2014-04-01

    Full Text Available Creatinine, uric acid, hypoxanthine and xanthine are important diagnostic biomarkers in human urine for gouty arthritis or renal disease diacrisis. A simple method for simultaneous determination of these biomarkers in urine based on reversed-phase high-performance liquid chromatography (RP-HPLC with ultraviolet (UV detector was proposed. After pretreatment by dilution, centrifugation and filtration, the biomarkers in urine samples were separated by ODS-BP column by elution with methanol/50 mM NaH2PO4 buffer solution at pH 5.26 (5:95. Good linearity between peak areas and concentrations of standards was obtained for the biomarkers with correlation coefficients in the range of 0.9957–0.9993. The proposed analytical method has satisfactory repeatability (the recovery of data in a range of creatinine, uric acid, hypoxanthine and xanthine was 93.49–97.90%, 95.38–96.45%, 112.46–115.78% and 90.82–97.13% with standard deviation of <5%, respectively and the limits of detection (LODs, S/N≥3 for creatinine, uric acid, hypoxanthine, and xanthine were 0.010, 0.025, 0.050 and 0.025 mg/L, respectively. The established method was proved to be simple, accurate, sensitive and reliable for the quantitation of gouty arthritis' biomarkers in human urine samples. The ratio of creatinine to uric acid was found to be a possible factor for assessment of gouty arthritis. Keywords: Gouty arthritis, Creatinine, Uric acid, Hypoxanthine, Xanthine, High-performance liquid chromatography

  13. Exploring the complexity of oil sands process-affected water by high efficiency supercritical fluid chromatography/orbitrap mass spectrometry.

    Science.gov (United States)

    Pereira, A S; Martin, J W

    2015-04-30

    Approximately 1 billion m(3) of oil sands process-affected water (OSPW) is currently stored in tailings ponds in Northern Alberta, Canada. The dissolved organic compounds in OSPW have been termed a supercomplex mixture of bitumen-derived substances and continuing efforts to understand its underlying chemical composition are important for evaluating its environmental hazards. Packed column supercritical fluid chromatography (SFC) was applied to OSPW analysis for the first time. By combining four columns in series (each 25 cm × 4.6 mm I.D., 5.0 µm bare silica) approximately 80,000 plates were achieved on a 1 m column. Using a simple fixed restrictor, the SFC eluent was coupled directly to ultrahigh-resolution orbitrap mass spectrometry (SFC/Orbitrap-MS). SFC/Orbitrap-MS, with positive and negative atmospheric pressure chemical ionization (APCI +/-), revealed the partial or full chromatographic separation of isomers for a wide array of chemical species, including naphthenic acids (Cn H2n + Z O2 ) and unknown sulfur- and nitrogen-containing molecules. For smaller compounds (e.g. naphthenic acids where n ≤10), or for larger structurally constrained compounds (e.g. C16 naphthenic acid with 9 double-bond equivalents), apparent baseline resolution of many isomers was possible. Isomer-specific MS/MS experiments furthermore allowed characterization of functional groups in novel species. For example, in APCI+ mode, up to 16 isomers of C6 H11 ON were revealed to have amide and amino functionalities. This combination of high efficiency chromatography and ultra-high mass resolution detection resulted in a powerful method with capabilities for characterizing or 'fingerprinting' unknown species with little interference. The method has great promise for environmental monitoring and forensics in the oil sands region, as well as for further studies on the composition of dissolved organic compounds in OSPW. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Analytical Method Validation of High-Performance Liquid Chromatography and Stability-Indicating Study of Medroxyprogesterone Acetate Intravaginal Sponges

    Directory of Open Access Journals (Sweden)

    Nidal Batrawi

    2017-02-01

    Full Text Available Medroxyprogesterone acetate is widely used in veterinary medicine as intravaginal dosage for the synchronization of breeding cycle in ewes and goats. The main goal of this study was to develop reverse-phase high-performance liquid chromatography method for the quantification of medroxyprogesterone acetate in veterinary vaginal sponges. A single high-performance liquid chromatography/UV isocratic run was used for the analytical assay of the active ingredient medroxyprogesterone. The chromatographic system consisted of a reverse-phase C18 column as the stationary phase and a mixture of 60% acetonitrile and 40% potassium dihydrogen phosphate buffer as the mobile phase; the pH was adjusted to 5.6. The method was validated according to the International Council for Harmonisation (ICH guidelines. Forced degradation studies were also performed to evaluate the stability-indicating properties and specificity of the method. Medroxyprogesterone was eluted at 5.9 minutes. The linearity of the method was confirmed in the range of 0.0576 to 0.1134 mg/mL ( R 2 > 0.999. The limit of quantification was shown to be 3.9 µg/mL. Precision and accuracy ranges were found to be %RSD <0.2 and 98% to 102%, respectively. Medroxyprogesterone capacity factor value of 2.1, tailing factor value of 1.03, and resolution value of 3.9 were obtained in accordance with ICH guidelines. Based on the obtained results, a rapid, precise, accurate, sensitive, and cost-effective analysis procedure was proposed for quantitative determination of medroxyprogesterone in vaginal sponges. This analytical method is the only available method to analyse medroxyprogesterone in veterinary intravaginal dosage form.

  15. Sensitive determination of nitrophenol isomers by reverse-phase high-performance liquid chromatography in conjunction with liquid-liquid extraction

    Science.gov (United States)

    A method for the highly sensitive determination of 2-, 3- and 4- nitrophenols was developed using reverse-phase high-performance liquid chromatography (RP-HPLC) with a UV photodiode array detector. Using a reverse-phase column and 40% aqueous acetonitrile as an eluent (i.e. isocratic elution), the i...

  16. Solid-phase extraction and reversed-phase high-performance liquid chromatography of the five major alkaloids in Narcissus confusus.

    Science.gov (United States)

    López, Susana; Bastida, Jaume; Viladomat, Francesc; Codina, Carles

    2002-01-01

    A novel, fast and precise method, combining solid-phase extraction and reversed-phase high-performance liquid chromatography is described for the quantitative determination of five alkaloids (galanthamine, N-formylnorgalanthamine, haemanthamine, homolycorine and tazettine/pretazettine) from bulbs of wild Narcissus confusus, a high galanthamine-containing plant species growing in the Iberian Peninsula.

  17. Chromatographic performance of synthetic polycrystalline diamond as a stationary phase in normal phase high performance liquid chromatography.

    Science.gov (United States)

    Peristyy, Anton; Paull, Brett; Nesterenko, Pavel N

    2015-04-24

    The chromatographic properties of high pressure high temperature synthesised diamond (HPHT) are investigated in normal phase mode of high performance liquid chromatography. Purified nonporous irregular shape particles of average particles size 1.2 μm and specific surface area 5.1 m(2) g(-1) were used for packing 100×4.6 mm ID or 50×4.6 mm ID stainless steel columns. The retention behaviour of several classes of compounds including alkyl benzenes, polyaromatic hydrocarbons (PAH), alkylphenylketones, phenols, aromatic acids and bases were studied using n-hexane-2-propanol mixtures as mobile phase. The results are compared with those observed for microdispersed sintered detonation nanodiamond (MSDN) and porous graphitic carbon (PGC). HPHT diamond revealed distinctive separation selectivity, which is orthogonal to that observed for porous graphitic carbon; while selectivities of HPHT diamond and microdispersed sintered detonation nanodiamonds are similar. Owing to non-porous particle nature, columns packed with high pressure high temperature diamond exhibited excellent mass transfer and produce separations with maximum column efficiency of 128,200 theoretical plates per meter. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Estado da arte da cromatografia gasosa de alta resolução e alta temperatura State of the art of high temperature high resolution gas chromatography

    Directory of Open Access Journals (Sweden)

    Alberto dos Santos Pereira

    2000-06-01

    Full Text Available The developments in stationary phase synthesis and capillary column technology, have opened new perspectives in analysis of high molecular mass compounds (³600 daltons and thermolabile organic compounds by High Temperature High Resolution Gas Chromatography (HT-HRGC. HT-HRGC is a new analytical borderline and its application to the analysis of high molecular mass compounds is still in its infancy. The apolar and medium polar gum phases can now be operated at temperatures up to 400-480ºC, being used for the analysis of n-alcanes up to C-100, lipids, oligosaccharides, industrial resins, polyglycerols, cyclodextrins, porphyrins, etc. This technique should play a leading role as a powerful tool, for many different analysis types, in multidisciplinary fields of Science.

  19. Simplifying and expanding analytical capabilities for various classes of doping agents by means of direct urine injection high performance liquid chromatography high resolution/high accuracy mass spectrometry.

    Science.gov (United States)

    Görgens, Christian; Guddat, Sven; Thomas, Andreas; Wachsmuth, Philipp; Orlovius, Anne-Katrin; Sigmund, Gerd; Thevis, Mario; Schänzer, Wilhelm

    2016-11-30

    So far, in sports drug testing compounds of different classes are processed and measured using different screening procedures. The constantly increasing number of samples in doping analysis, as well as the large number of substances with doping related, pharmacological effects require the development of even more powerful assays than those already employed in sports drug testing, indispensably with reduced sample preparation procedures. The analysis of native urine samples after direct injection provides a promising analytical approach, which thereby possesses a broad applicability to many different compounds and their metabolites, without a time-consuming sample preparation. In this study, a novel multi-target approach based on liquid chromatography and high resolution/high accuracy mass spectrometry is presented to screen for more than 200 analytes of various classes of doping agents far below the required detection limits in sports drug testing. Here, classic groups of drugs as diuretics, stimulants, β2-agonists, narcotics and anabolic androgenic steroids as well as various newer target compounds like hypoxia-inducible factor (HIF) stabilizers, selective androgen receptor modulators (SARMs), selective estrogen receptor modulators (SERMs), plasma volume expanders and other doping related compounds, listed in the 2016 WADA prohibited list were implemented. As a main achievement, growth hormone releasing peptides could be implemented, which chemically belong to the group of small peptides (0.99), limit of detection (0.1-25ng/mL; 3'OH-stanozolol glucuronide: 50pg/mL; dextran/HES: 10μg/mL) and matrix effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Metabolite Profile of Salidroside in Rats by Ultraperformance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry and High-Performance Liquid Chromatography Coupled with Quadrupole-Linear Ion Trap Mass Spectrometry.

    Science.gov (United States)

    Hu, Zhiwei; Wang, Ziming; Liu, Yong; Wu, Yan; Han, Xuejiao; Zheng, Jian; Yan, Xiufeng; Wang, Yang

    2015-10-21

    In the present work, the salidroside metabolite profile in rat urine was investigated, and subsequently the metabolic pathways of salidroside were proposed. After administrations of salidroside at an oral dose of 100 or 500 mg/kg, rat urine samples were collected and pretreated with methanol to precipitate the proteins. The pretreated samples were analyzed by an Acquity ultraperformance liquid chromatography (UPLC) coupled with an HSS T3 column and detected by quadrupole time-of-flight mass spectrometry (Q-TOF-MS) or high-performance liquid chromatography coupled with hybrid triple-quadrupole linear ion trap mass spectrometry (HPLC/Q-trap-MS). A total of eight metabolites were detected and identified on the basis of the characteristics of their protonated ions in the urine samples. The results elucidated that salidroside was metabolized via glucuronidation, sulfation, deglycosylation, hydroxylation, methylation, and dehydroxylation pathways in vivo.

  1. Analysis of major antioxidants from extracts of Myrmecodia pendans by UV/visible spectrophotometer, liquid chromatography/tandem mass spectrometry, and high-performance liquid chromatography/UV techniques.

    Science.gov (United States)

    Engida, Adam Mekonnen; Faika, Sitti; Nguyen-Thi, Bich Thuyen; Ju, Yi-Hsu

    2015-06-01

    In the present work, heat reflux extraction with ethanol/water (80:20; v/v) as the solvent was used to extract antioxidants from Myrmecodia pendans. The crude extract (CE) was fractionated using hexane and ethyl acetate. Ethyl acetate fraction (EAF) and aqueous fraction were collected. Antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power of the CE, EAF, and aqueous fraction were evaluated. EAF showed comparable antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power to those of the CE. UV/visible, liquid chromatography/electrospray ionization/tandem mass spectrometry, and high-performance liquid chromatography were employed for identifying the major antioxidant compounds in the EAF. Three major phenolic compounds (rosmarinic acid, procyanidin B1, and polymer of procyanidin B1) were identified. The first two compounds were confirmed and quantified by high-performance liquid chromatography using authentic standards, but confirmation of the third compound was hampered by a lack of commercial standard. Concentrations of rosmarinic acid and procyanidin B1 in the EAF were found to be 20.688 ± 1.573 mg/g dry sample and 3.236 ± 0.280 mg/g dry sample, respectively. All these three compounds are reported for the first time in sarang semut. Copyright © 2014. Published by Elsevier B.V.

  2. Analysis of major antioxidants from extracts of Myrmecodia pendans by UV/visible spectrophotometer, liquid chromatography/tandem mass spectrometry, and high-performance liquid chromatography/UV techniques

    Directory of Open Access Journals (Sweden)

    Adam Mekonnen Engida

    2015-06-01

    Full Text Available In the present work, heat reflux extraction with ethanol/water (80:20; v/v as the solvent was used to extract antioxidants from Myrmecodia pendans. The crude extract (CE was fractionated using hexane and ethyl acetate. Ethyl acetate fraction (EAF and aqueous fraction were collected. Antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power of the CE, EAF, and aqueous fraction were evaluated. EAF showed comparable antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl-radical radical and ferric reducing power to those of the CE. UV/visible, liquid chromatography/electrospray ionization/tandem mass spectrometry, and high-performance liquid chromatography were employed for identifying the major antioxidant compounds in the EAF. Three major phenolic compounds (rosmarinic acid, procyanidin B1, and polymer of procyanidin B1 were identified. The first two compounds were confirmed and quantified by high-performance liquid chromatography using authentic standards, but confirmation of the third compound was hampered by a lack of commercial standard. Concentrations of rosmarinic acid and procyanidin B1 in the EAF were found to be 20.688 ± 1.573 mg/g dry sample and 3.236 ± 0.280 mg/g dry sample, respectively. All these three compounds are reported for the first time in sarang semut.

  3. Development of a high-performance liquid chromatography method for the determination of florfenicol in animal feedstuffs.

    Science.gov (United States)

    Yang, JinJing; Sun, GuiZhi; Qian, MingRong; Huang, LingLi; Ke, XianBing; Yang, Bo

    2017-11-15

    An effective thin layer chromatography (TLC) purification procedure coupled to high-performance liquid chromatography (HPLC) method was developed for the determination of florfenicol (FF) in pig, chicken and fish feedstuffs. The feedstuff samples were extracted with ethyl acetate, defatted with n-hexane saturated with acetonitrile, and further purified by TLC. The chromatographic separation was performed on a Waters Symmetry C18 column using an isocratic procedure with acetonitrile-water (35:65, v/v) at 0.6mL/min. The ultraviolet (UV) detector was set at a wavelength of 225nm. The FF concentrations in feedstuff samples were quantified using a standard curve. Good linear correlations (y=159075x-15054, r>0.9999) were achieved within the concentration range of 0.05-200μg/mL. The recoveries of FF spiked at levels of 1, 100 and 1000μg/g ranged from 80.6% to 105.3% with the intra-day and inter-day relative standard deviation (RSD) less than 9.3%. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.02 and 0.06mg/kg for pig feedstuffs, 0.02 and 0.07mg/kg for chicken feedstuffs, and 0.02 and 0.05mg/kg for fish feedstuffs, respectively. This reliable, simple and cost-effective method could be applied to the routine monitoring of FF in animal feedstuffs. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Quantitative and pattern recognition analysis of five marker compounds in Raphani semen using high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yeon Woo; Lee, Joo Sang; Zhao, Bing Tian; Woo, Mi Hee; Min, Byung Sun [College of Pharmacy, Drug Research and Development Center, Catholic University of Daegu, Gyeongsan (Korea, Republic of); Kim, Jeong Ah [College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu (Korea, Republic of); Eun, Rhan Woo [College of Pharmacy, Chosun University, Gwangju (Korea, Republic of)

    2015-09-15

    A rapid and simple high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method was developed for the quantitative analysis of Raphani Semen (RS). This method was successfully used to determine the five main phenolic compounds found in RS specimens from different production regions. The compounds included sinapine thiocyanate (1), β-d-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (2), isorhamnetin 3,4′-di-O-β-d-glucoside (3), β-d-(3-O-sinapoyl)-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (4), and β-d-(3,4-O-disinapoyl)-fructofuranosyl-α-d-(6-O-sinapoyl)-glucopyranoside (5). The marker compounds were separated using an Agilent Eclipse XDB-C18 column (5.0 µm, 150 × 4.6 mm i.d.) by gradient elution with acetonitrile/water/0.1% trifluoroacetic acid (TFA) as the mobile phase (flow rate, 1.0 mL/min). This method was fully validated with respect to linearity, precision, accuracy, stability, and robustness. The HPLC analytical method was validated to conduct a pattern recognition analysis by repeatedly analyzing 56 seed samples including 55 RS (C01–C49 and K50–K55) and 1 Brassicae Semen samples. In addition, a content standard for RS was proposed. Compounds 1 and 4 were revealed as major components in the HPLC chromatogram, and their contents ranged from 0.06 to 0.20 and 0.02 to 0.35 mg/g, respectively. These results demonstrate the successful development of an analytical method suitable for evaluating the quality and distinguishing the origin of RS. In addition, we briefly describe the crucial liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical conditions for the precise simultaneous quantification of the marker compounds.

  5. Residue level and dissipation pattern of lepimectin in shallots using high-performance liquid chromatography coupled with photodiode array detection.

    Science.gov (United States)

    Kim, Sung-Woo; Rahman, Md Musfiqur; Abd El-Aty, A M; Truong, Lieu T B; Choi, Jeong-Heui; Park, Joon-Seong; Kim, Mi-Ra; Shin, Ho-Chul; Shim, Jae-Han

    2016-11-01

    Lepimectin, as an emulsifiable concentrate, was sprayed on shallots at the recommended dose rate (10 mL/20 L) to determine its residue levels, dissipation pattern, pre-harvest residue limits (PHRLs), and health risk. Samples were randomly collected over 10 days, extracted with acetonitrile, purified using an amino solid-phase extraction (NH2 -SPE) cartridge and analyzed using a high-performance liquid chromatography-photodiode array detection method. Field-incurred samples were confirmed using ultra-performance liquid chromatography-tandem mass spectrometry. The linearity was excellent, with a determination coefficient (R(2) ) of ≥0.9991. The recoveries at two spiking levels (0.2 and 1.0 mg/kg) ranged from 84.49 to 87.64% with relative standard deviations of ≤7.04%. The developed method was applied to field samples grown in separate greenhouses, one located in Naju and one in Muan, in the Republic of Korea. The dissipation pattern was described by first-order kinetics with half-lives of 1.9 (Naju) and 1.7 days (Muan). The PHRL curves indicated that, if the lepimectin residues are <0.18 (Naju) and <0.13 mg/kg (Muan) 5 days before harvest, the residue levels will be lower than the maximum residue limit (0.05 mg/kg) upon harvesting. The risk assessment data indicated that lepimectin is safe for use in the cultivation of shallots, with no risk of detrimental effects to the consumer. Copyright © 2016 John Wiley & Sons, Ltd.

  6. ORGANIC-HIGH IONIC STRENGTH AQUEOUS SOLVENT SYSTEMS FOR SPIRAL COUNTER-CURRENT CHROMATOGRAPHY: GRAPHIC OPTIMIZATION OF PARTITION COEFFICIENT

    Science.gov (United States)

    Zeng, Yun; Liu, Gang; Ma, Ying; Chen, Xiaoyuan; Ito, Yoichiro

    2012-01-01

    A new series of organic-high ionic strength aqueous two-phase solvents systems was designed for separation of highly polar compounds by spiral high-speed counter-current chromatography. A total of 21 solvent systems composed of 1-butanol-ethanol-saturated ammonium sulfate-water at various volume ratios are arranged according to an increasing order of polarity. Selection of the two-phase solvent system for a single compound or a multiple sample mixture can be achieved by two steps of partition coefficient measurements using a graphic method. The capability of the method is demonstrated by optimization of partition coefficient for seven highly polar samples including tartrazine (K=0.77), tryptophan (K=1.00), methyl green (K= 0.93), tyrosine (0.81), metanephrine (K=0.89), tyramine (K=0.98), and normetanephrine (K=0.96). Three sulfonic acid components in D&C Green No. 8 were successfully separated by HSCCC using the graphic selection of the two-phase solvent system. PMID:23467197

  7. High-performance liquid chromatography of phosphatidylcholine and sphingomyelin with detection in the region of 200 nm.

    Science.gov (United States)

    Jungalwala, F B; Evans, J E; McCluer, R H

    1976-01-01

    A sensitive method for the separation of phosphatidylcholine and sphingomyelin by high-performance liquid chromatographic analysis is described. The elution of the phospholipids from a microparticulate (10 mum) silica-gel chromatographic column was monitored with an ultraviolet spectromonitor at 203 nm. Acetonitrile/methanol/water (65:21:14, by vol.) was used as the solvent. It was shown by using synthetic phosphatidylcholines of knowm fatty acid composition and of varying degree of unsaturation that the absorption at 203 nm was primarily due to the isolated double bonds and the response measured varied with the degree of unsaturation. Approx. 1 nmol of phosphatidylcholine, containing at least one double bond per molecule, can be detected. The amounts of phosphatidylcholine and sphingomyelin could be determined by high-performance liquid chromatography and ultraviolet absorption if the apparent extinction coefficient of the material analyzed was established. Alternatively, peaks were collected and the phospholipids were determined by the analysis of phosphorus. The analysis of phosphatidylcholine and sphingomyelin present in the lipid extracts from animal tissues, blood and amniotic fluids were made without interference from other phospholipids or ultraviolet-absorbing material. The method described here is complementary to the high-performance liquid chromatographic method described previously for the analysis of ethanolamine-containing phosphoglycerides and serine-containing phosphoglycerides [Jungalwala, Turel, Evans and McCluer (1975) Biochem. J. 145, 517-526]. PMID:938476

  8. Magnetic graphene dispersive solid phase extraction combining high performance liquid chromatography for determination of fluoroquinolones in foods.

    Science.gov (United States)

    He, Xin; Wang, Geng Nan; Yang, Kun; Liu, Hui Zhi; Wu, Xia Jun; Wang, Jian Ping

    2017-04-15

    In this study, a magnetic graphene-based dispersive solid phase extraction method was developed that was combined with high performance liquid chromatography to determine the residues of fluoroquinolone drugs in foods of animal origin. During the experiments, several parameters possible influencing the extraction performance were optimized (amount of magnetic graphene, sample pH, extraction time and elution solution). This extraction method showed high absorption capacities (>6800ng) and high enrichment factors (68-79-fold) for seven fluoroquinolones. Furthermore, this absorbent could be reused for at least 40 times. The limits of detection were in the range of 0.05-0.3ng/g, and the recoveries from the standards fortified blank samples (bovine milk, chicken muscle and egg) were in the range of 82.4-108.5%. Therefore, this method could be used as a simple and sensitive tool to determine the residues of fluoroquinolones in foods of animal origin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Investigation of pharmaceuticals in processed animal by-products by liquid chromatography coupled to high-resolution mass spectrometry.

    Science.gov (United States)

    Nácher-Mestre, Jaime; Ibáñez, María; Serrano, Roque; Boix, Clara; Bijlsma, Lubertus; Lunestad, Bjørn Tore; Hannisdal, Rita; Alm, Martin; Hernández, Félix; Berntssen, Marc H G

    2016-07-01

    There is an on-going trend for developing more sustainable salmon feed in which traditionally applied marine feed ingredients are replaced with alternatives. Processed animal products (PAPs) have been re-authorized as novel high quality protein ingredients in 2013. These PAPs may harbor undesirable substances such as pharmaceuticals and metabolites which are not previously associated with salmon farming, but might cause a potential risk for feed and food safety. To control these contaminants, an analytical strategy based on a generic extraction followed by ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS) using quadrupole time-of-flight mass analyzer (QTOF MS) was applied for wide scope screening. Quality control samples, consisting of PAP commodities spiked at 0.02, 0.1 and 0.2 mg/kg with 150 analytes, were injected in every sample batch to verify the overall method performance. The methodology was applied to 19 commercially available PAP samples from six different types of matrices from the EU animal rendering industry. This strategy allows assessing possible emergent risk exposition of the salmon farming industry to 1005 undesirables, including pharmaceuticals, several dyes and relevant metabolites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. [Application of denaturing high performance liquid chromatography for the detection of maternal DNA contamination during prenatal diagnosis].

    Science.gov (United States)

    Gao, Lijie; Long, Yanming; Zhang, Rong; Li, Shuang; Zhang, Fenghuan; He, Guoping

    2014-02-01

    To establish a high-quality method for detecting short tandem repeats(STR) using denaturing high performance liquid chromatography(DHPLC) in order to exclude maternal contamination and improve the accuracy of prenatal diagnosis. Two families were recruited. DNA was extracted from blood samples from the parents as well as amniotic fluid. Sixteen STR sites were amplified and analyzed based on the range of allele length reported by a STR database. Maternal DNA was mixed with DNA derived from amniotic fluid samples with the ratio 1:1, 1:4, 1:9, 1:19 and 1:99. vWA STR site was detected with DHPLC to confirm the sensitivity of detection. Sixteen STR sites were analyzed by DHPLC, for which at least 10 were found to be different between the mothers and fetuses. The detection rate, with maternal contamination excluded, was 66.7%. And the sensitivity of detection was 1-10%. Maternal contamination of amniotic fluid can be rapidly excluded with accuracy with DHPLC, which features a high sensitivity and good quality control, and can meet the European standards and provide a reliable quality control platform for prenatal diagnosis.

  11. [Qualitative and quantitative analysis of amygdalin and its metabolite prunasin in plasma by ultra-high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry].

    Science.gov (United States)

    Gao, Meng; Wang, Yuesheng; Wei, Huizhen; Ouyang, Hui; He, Mingzhen; Zeng, Lianqing; Shen, Fengyun; Guo, Qiang; Rao, Yi

    2014-06-01

    A method was developed for the determination of amygdalin and its metabolite prunasin in rat plasma after intragastric administration of Maxing shigan decoction. The analytes were identified by ultra-high performance liquid chromatography-tandem quadrupole time of flight mass spectrometry and quantitatively determined by ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry. After purified by liquid-liquid extraction, the qualitative analysis of amygdalin and prunasin in the plasma sample was performed on a Shim-pack XR-ODS III HPLC column (75 mm x 2.0 mm, 1.6 microm), using acetonitrile-0.1% (v/v) formic acid aqueous solution. The detection was performed on a Triple TOF 5600 quadrupole time of flight mass spectrometer. The quantitative analysis of amygdalin and prunasin in the plasma sample was performed by separation on an Agilent C18 HPLC column (50 mm x 2.1 mm, 1.7 microm), using acetonitrile-0.1% (v/v) formic acid aqueous solution. The detection was performed on an AB Q-TRAP 4500 triple quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operated in negative ion mode and multiple-reaction monitoring (MRM) mode. The qualitative analysis results showed that amygdalin and its metabolite prunasin were detected in the plasma sample. The quantitative analysis results showed that the linear range of amygdalin was 1.05-4 200 ng/mL with the correlation coefficient of 0.999 0 and the linear range of prunasin was 1.25-2 490 ng/mL with the correlation coefficient of 0.997 0. The method had a good precision with the relative standard deviations (RSDs) lower than 9.20% and the overall recoveries varied from 82.33% to 95.25%. The limits of detection (LODs) of amygdalin and prunasin were 0.50 ng/mL. With good reproducibility, the method is simple, fast and effective for the qualitative and quantitative analysis of the amygdalin and prunasin in plasma sample of rats which were administered by Maxing shigan decoction.

  12. Separation of nine compounds from Salvia plebeia R.Br. using two-step high-speed counter-current chromatography with different elution modes.

    Science.gov (United States)

    Ren, Da-Bing; Qin, Yan-Hua; Yun, Yong-Huan; Lu, Hong-Mei; Chen, Xiao-Qing; Liang, Yi-Zeng

    2014-08-01

    Nine compounds were successfully separated from Salvia plebeia R.Br. using two-step high-speed counter-current chromatography with three elution modes. Elution-extrusion counter-current chromatography was applied in the first step, while classical counter-current chromatography and recycling counter-current chromatography were used in the second step. Three solvent systems, n-hexane/ethyl acetate/ethanol/water (4:6.5:3:7, v/v), methyl tert-butyl ether/ethyl acetate/n-butanol/methanol/water (6:4:1:2:8, v/v) and n-hexane/ethyl acetate/methanol/water (5:5.5:5:5, v/v) were screened and optimized for the two-step separation. The separation yielded nine compounds, including caffeic acid (1), 6-hydroxyluteuolin-7-glucoside (2), 5,7,3',4'-tetrahydroxy-6-methoxyflavanone-7-glucoside (3), nepitrin (4), rosmarinic acid (5), homoplantaginin (6), nepetin (7), hispidulin (8), and 5,6,7,4'-tertrahydroxyflavone (9). To the best of our knowledge, 5,7,3',4'-tetrahydroxy-6-methoxyflavanone-7-glucoside and 5,6,7,4'-tertrahydroxyflavone have been separated from Salvia plebeia R.Br. for the first time. The purities and structures of these compounds were identified by high-performance liquid chromatography, electrospray ionization mass spectrometry, (1)H and (13)C NMR spectroscopy. This study demonstrates that high-speed counter-current chromatography is a useful and flexible tool for the separation of components from a complex sample. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. An online coupled peritoneal macrophage/cell membrane chromatography and high-performance liquid chromatography/mass spectrometry method to screen for anti-inflammatory components from the Chinese traditional medicine Chloranthus multistachys Pei.

    Science.gov (United States)

    Li, Weifeng; Xing, Wei; Wang, Sicen; Fan, Ting; Huang, Huimin; Niu, Xiaofeng; He, Langchong

    2013-11-01

    Cell membrane chromatography (CMC) is a chromatographic biological affinity method that uses specific cell membranes as the stationary phase. In this study, a novel peritoneal macrophage/cell membrane chromatography (PM/CMC)-online-high performance liquid chromatography/mass spectrometry (HPLC/MS) method was established to screen for the anti-inflammatory components from traditional Chinese medicines using hydrocortisone and dexamethasone as standards. The stationary phase of the CMC employed mouse peritoneal macrophage cell membranes. This method was applied to the purification and identification of components in extracts of Chloranthus multistachys Pei. The major component retained by CMC was identified as isofraxidin by HPLC/MS. In vitro experiments revealed that IF was able to inhibit the production of nitric oxide and tumor necrosis factor-α in lipopolysaccharide-stimulated mice and peritoneal macrophages in a dose-dependent manner. The results demonstrated that the PM/CMC-online-HPLC/MS is an effective screening system for the rapid detection, enrichment, and identification of target components from complex samples. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Assay for trenbolone and its metabolite 17 alpha-trenbolone in bovine urine based on immunoaffinity chromatographic clean-up and off-line high-performance liquid chromatography-thin-layer chromatography.

    Science.gov (United States)

    van Ginkel, L A; van Blitterswijk, H; Zoontjes, P W; van den Bosch, D; Stephany, R W

    1988-07-22

    An high-performance liquid chromatography (HPLC)-thin-layer chromatography (TLC) method was developed to detect the illegal use of the xenobiotic growth promotor Trenbolone acetate (TBA). Very effective clean-up of bovine urine was achieved by immunoaffinity chromatography (IAC). The active form of TBA, the steroid 17 beta-Trenbolone (17 beta-TB), as well as its major metabolite 17 alpha-Trenbolone (17 alpha-TB), were assayed simultaneously with HPLC and on-line UV detection. The fraction containing 17 alpha-TB and 17 beta-TB (TB-fraction) was collected, and for confirmation 17 beta- and 17 alpha-TB were subsequently separated and identified by TLC. The limit of detection by on-line HPLC-UV (350 nm) was 1-2 micrograms TB/l. Off-line TLC detection was even more sensitive, 0.5 microgram 17 beta- or 17 alpha-TB/1. The assay was validated by investigating urine samples from veal calves implanted with TBA. The presence of 17 beta- and 17 alpha-TB was clearly demonstrated. A survey of the illegal use of TBA in cattle was performed by applying the assay to urine obtained at slaughter. No residues of TBA or its metabolites were found in any of the 144 random samples from the Dutch public health surveillance programme.

  15. Analysis of Camellia sinensis green and black teas via ultra high performance liquid chromatography assisted by liquid-liquid partition and two-dimensional liquid chromatography (size exclusion × reversed phase).

    Science.gov (United States)

    Scoparo, Camila T; de Souza, Lauro M; Dartora, Nessana; Sassaki, Guilherme L; Gorin, Philip A J; Iacomini, Marcello

    2012-01-27

    Green and black teas (Camellia sinensis) contain compounds ranging from simple phenolics to complex glycosides, many of which have well-recognized health benefits. Here, we describe two methodologies aiming to achieve a comprehensive analysis of hydro-alcoholic extracts of C. sinensis. In the first step, the extracts were partitioned in water, n-butanol, ethyl acetate and chloroform to separate the compounds according to their polarity, yielding less complex samples to be analyzed by ultra high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS). Additionally, a comprehensive two dimensional liquid chromatography (2D-LC) technique, employing size exclusion chromatography (SEC) × reversed phase (BEH-C18) was developed. The following compounds were identified on the basis of retention time, UV-spectra and MS fragmentation patterns: catechins, theaflavins and their gallate derivatives; kaempferol, quercetin and myricetin mono-, di-, tri- and tetraglycosides; esters of quinic acid and gallic or hydroxycinnamic acids; purine alkaloids, such as caffeine and theobromine and many lipids. Additionally, there were many novel compounds that were previously undescribed, such as saponin isomers and gallic acid esters of four glycosides of myricetin, quercetin and kaempferol. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Simultaneous determination of 14 oil-soluble synthetic dyes in chilli products by high performance liquid chromatography with a gel permeation chromatography clean-up procedure.

    Science.gov (United States)

    Zhu, Yonghong; Zhao, Bo; Xiao, Ruiqi; Yun, Wen; Xiao, Zhaojing; Tu, Dawei; Chen, Shiqi

    2014-02-15

    A method was developed for the simultaneous determination of 14 fat-soluble dyes in chilli products. The samples were extracted with hexane/acetone. The cleanup was performed with gel permeation chromatography (GPC) cleanup system. A HPLC separation was performed using variable wavelength detector and a gradient elution with 0.1% formic acid and methanol-acetonitrile (1:1, v/v) as the mobile phases. Good linearity (R² ≥ 0.995) was observed between 0.1 and 5.0 μg/mL. Detection limits of the investigated dyes, which were evaluated at signal to noise ratio of 3, were in the ranges of 11-71 μg/kg. The recoveries of the 14 synthetic colourants in three matrices ranged from 73.4% to 103.5%. Relative standard deviations ranged from 3.7% to 12.3%. The method has been successfully used for the determination of banned dyes in real samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Systematic Optimization of Long Gradient Chromatography Mass Spectrometry for Deep Analysis of Brain Proteome

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hong; Yang, Yanling; Li, Yuxin; Bai, Bing; Wang, Xusheng; Tan, Haiyan; Liu, Tao; Beach, Thomas G.; Peng, Junmun; Wu, Zhiping

    2015-02-06

    Development of high resolution liquid chromatography (LC) is essential for improving the sensitivity and throughput of mass spectrometry (MS)-based proteomics. Here we present systematic optimization of a long gradient LC-MS/MS platform to enhance protein identification from a complex mixture. The platform employed an in-house fabricated, reverse phase column (100 μm x 150 cm) coupled with Q Exactive MS. The column was capable of achieving a peak capacity of approximately 700 in a 720 min gradient of 10-45% acetonitrile. The optimal loading level was about 6 micrograms of peptides, although the column allowed loading as many as 20 micrograms. Gas phase fractionation of peptide ions further increased the number of peptide identification by ~10%. Moreover, the combination of basic pH LC pre-fractionation with the long gradient LC-MS/MS platform enabled the identification of 96,127 peptides and 10,544 proteins at 1% protein false discovery rate in a postmortem brain sample of Alzheimer’s disease. As deep RNA sequencing of the same specimen suggested that ~16,000 genes were expressed, current analysis covered more than 60% of the expressed proteome. Further improvement strategies of the LC/LC-MS/MS platform were also discussed.

  18. Quality control of Chinese herbal tonic wine by high performance liquid chromatography fingerprint

    NARCIS (Netherlands)

    Wei, X.J.; Zhang, H.; Wang, W.F.; Li, B.; Yang Zhu, Yang

    2007-01-01

    Herbal tonic wines are alcoholic drinks in which medicinal herbs are soaked and extracted. These drinks are considered having various health functions. However, the quality of herbal products is largely influenced by the origin and harvest season of the herbs. Due to its high commercial value,

  19. Analysis of carprofen dosage forms and drug substance by high-performance liquid chromatography.

    Science.gov (United States)

    Ross, A J; Del Mauro, M D; Sokoloff, H K; Casey, D L

    1984-09-01

    A high-performance liquid chromatographic method for the analysis of carprofen in solid dosage forms and as the bulk drug substance was developed. The simple, accurate, reproducible, and stability-indicating method was shown to be applicable to drug substance and dosage form stability studies, as well as the quality control of carprofen dosage forms.

  20. Effects of high power ultrasound on all-E-β-carotene, newly formed compounds analysis by ultra-high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Carail, Michel; Fabiano-Tixier, Anne-Sylvie; Meullemiestre, Alice; Chemat, Farid; Caris-Veyrat, Catherine

    2015-09-01

    To study effects of high power ultrasound treatment (20 kHz) on β-carotene degradation, a second-order central composite design (CCD) was performed to investigate maximum β-carotene loss with three independent factors (ultrasonic intensity, sonication time, and temperature). Results based on variance analysis and Pareto chart have shown that sonication time is the most important factor, followed by ultrasonic intensity level. The evolved degradation products have been tentatively identified using ultra high performance liquid chromatography coupled to both diode array detector and a mass spectrometer (UHPLC-DAD-MS). The main degradation products, tentatively identified, are three Z-isomers of β-carotene and seven β-apo-carotenals/ones. Hypothesis on the degradation mechanism of carotenoids are presented. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. HighResNPS.com – an Internet Database for Liquid Chromatography - High Resolution Mass Spectrometry Screening for New Psychoactive Substances

    DEFF Research Database (Denmark)

    Dalsgaard, Petur Weihe; Mollerup, Christian Brinch; Mardal, Marie

    Background/Introduction: The number of new psychoactive substances (NPS) is constantly increasing which makes it challenging to keep the screening libraries updated with the relevant analytical targets. Liquid chromatography coupled High Resolution Mass Spectrometry (LC-HRMS) screening methods...... frequently utilize accurate mass of fragment ions for identification, in addition to retention time and accurate mass of precursor ions. The fragment ion information is obtained with data independent acquisition or data dependent acquisition. Both tend to generate similar fragment ions, when acquired...... cannabinoids and their metabolites constitute more than 60% of the database and opioids and their metabolites account for around 15% of the entries. 74% of the entries in HighResNPS are present in the European Database on New Drugs (EDND) governed by the European Monitoring Centre for Drugs and Drug Addiction...

  2. [Identification of the chemical compositionsof Verbena officinalis L. extract by high performance liquid chromatography-photodiode array-high resolution mass spectrometry].

    Science.gov (United States)

    Sun, Yuming; Wang, Yueyue; Cai, Rui; Zhang, Hua; Wang, Yulin

    2017-09-08

    To investigate the main chemical compositions of Verbena officinals L. extract, a qualitative high performance liquid chromatography-photodiode array-high resolution mass spectrometry (HPLC-PDA-HRMS) method was established. The structures of the compounds detected were identified by analyzing the chromatographic profiles and the corresponding mass spectra obtained by full scan and MS(n) full scan. Twenty one compounds including iridoid glycosides, flavonoids, triterpenoids, phenylpropanoids and phenolic diterpenoids were identified, and six of them were not reported in other literatures about Verbena officinalis L. extract, such as carnosic acid, carnosol, rosmanol, isorosmanol, rosmarinic acid and acacetin-7-O-rutinoside. This method is simple, rapid, accurate and sensitive. It provides a reliable scientific basis for the identification of the authenticity and quality control of Chinese medicinal materials.

  3. Selective on-line detection of boronic acids and derivatives in high-performance liquid chromatography eluates by post-column reaction with alizarin

    NARCIS (Netherlands)

    Duval, F.L.; Wardani, P.A.; Zuilhof, H.; Beek, van T.A.

    2015-01-01

    An on-line high-performance liquid chromatography (HPLC) method for the rapid and selective detection of boronic acids in complex mixtures was developed. After optimization experiments at an HPLC flow rate of 0.40 mL/min, the HPLC-separated analytes were mixed post-column with a solution of 75 µM

  4. Ultra-high-performance liquid chromatography-tandem mass spectrometry measurement of climbazole deposition from hair care products onto artificial skin and human scalp

    NARCIS (Netherlands)

    Chen, G.; Hoptroff, M.; Fei, X.; Su, Y.; Janssen, H.-G.

    2013-01-01

    A sensitive and specific ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the measurement of climbazole deposition from hair care products onto artificial skin and human scalp. Deuterated climbazole was used as the internal

  5. High-performance liquid chromatography coupled to enzyme-amplified biochemical detection for the analysis of hemoglobin after pre-column biotinylation

    NARCIS (Netherlands)

    van Bommel, M.R.; Jong, A.P.J.M.; Tjaden, U.R.; Irth, H.; van der Greef, J.

    2000-01-01

    The determination of proteins with enzyme-amplified biochemical detection (EA-BCD) coupled on-line with high-performance liquid chromatography (HPLC) is demonstrated. The EA-BCD system was developed to detect biotin-containing compounds. Hemoglobin, which was used as a model compound, was

  6. An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes

    NARCIS (Netherlands)

    Zhang, Q.; van der Klift, E.J.C.; Janssen, H.-G.; van Beek, T.A.

    2009-01-01

    An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high

  7. Development of a method for quantitation of retinol and retinyl palmitate in human serum using high-performance liquid chromatography atmospheric pressure chemical ionization mass spectrometry.

    NARCIS (Netherlands)

    Breemen, van R.B.; Nikolic, D.; Xu, X.Y.; Xiong, Y.S.; Lieshout, van M.; West, C.E.; Schilling, A.B.

    1998-01-01

    A method for the quantitative analysis of the vitamin A compounds all-trans-retinol and all-trans-retinyl palmitate was developed using high-performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (APCI-LC-MS). Unlike previous quantitative mass spectrometric

  8. Simultaneous quantification of purine and pyrimidine bases, nucleosides and their degradation products in bovine blood plasma by high performance liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    Nielsen, Charlotte Stentoft; Vestergaard, Mogens; Løvendahl, Peter

    2014-01-01

    ), and their degradation products (uric acid, allantoin, β-alanine, β-ureidopropionic acid, β-aminoisobutyric acid) in blood plasma of dairy cows. The high performance liquid chromatography-based technique coupled to electrospray ionization tandem mass spectrometry (LC–MS/MS) was combined with individual matrix...

  9. Validation of a high performance liquid chromatography analysis for the determination of noradrenaline and adrenaline in human urine with an on-line sample purification

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Kristiansen, J; Nielsen, J L

    1999-01-01

    A high performance liquid chromatography (HPLC) method with fluorescence detection including an on-line purification was established for determination of catecholamines in human urine. The method was evaluated using samples of pooled urine spiked with catecholamines and validated for measurements...

  10. Implementation of Isavuconazole in a Fluorescence-Based High-Performance Liquid Chromatography Kit Allowing Simultaneous Detection of All Four Currently Licensed Mold-Active Triazoles

    DEFF Research Database (Denmark)

    Jorgensen, Rene; Andersen, Siri Rytcher; Astvad, Karen Marie Thyssen

    2017-01-01

    . The method involves using a kit from ChromSystems intended for TDM of itraconazole (ITZ), posaconazole (PSZ), and voriconazole (VRZ) in serum/plasma for sample preparation and high-performance liquid chromatography, using fluorescence detection with emission and excitation wavelengths set to 261 and 366 nm...

  11. Receptor-based high-throughput screening and identification of estrogens in dietary supplements using bioaffinity liquid-chromatography ion mobility mass spectrometry

    NARCIS (Netherlands)

    Aqai, P.; Gómez Blesa, N.; Major, H.; Pedotti, P.; Varani, L.; Ferrero, V.E.V.; Haasnoot, W.; Nielen, M.W.F.

    2013-01-01

    A high-throughput bioaffinity liquid chromatography-mass spectrometry (BioMS) approach was developed and applied for the screening and identification of recombinant human estrogen receptor a (ERa) ligands in dietary supplements. For screening, a semi-automated mass spectrometric ligand binding assay

  12. Qualitative aspects and validation of a screening method for pesticides in vegetables and fruits based on liquid chromatography coupled to full scan high resolution (Orbitrap) mass spectrometry

    NARCIS (Netherlands)

    Mol, J.G.J.; Zomer, P.; Koning, de A.

    2012-01-01

    The analytical capabilities of liquid chromatography with single-stage high-resolution mass spectrometry have been investigated with emphasis on qualitative aspects related to selective detection during screening and to identification. The study involved 21 different vegetable and fruit commodities,

  13. Ergot alkaloids in rye flour determined by solid-phase cation-exchange and high-pressure liquid chromatography with fluorescence detection

    DEFF Research Database (Denmark)

    Storm, Ida Marie Lindhardt Drejer; Rasmussen, Peter Have; Strobel, B.W.

    2008-01-01

    Ergot alkaloids are mycotoxins that are undesirable contaminants of cereal products, particularly rye. A method was developed employing clean-up by cation-exchange solid-phase extraction, separation by high-performance liquid chromatography under alkaline conditions and fluorescence detection...

  14. Comparative oxidation state specific analysis of arsenic species by high-performance liquid chromatography-inductively coupled-mass spectrometry and hydride generation-cryotrapping-atomic absorption spectrometry

    Science.gov (United States)

    The formation of methylarsonous acid (MAsIII) and dimethylarsinous acid (DMAsIII) in the course of inorganic arsenic (iAs) metabolism plays an important role in the adverse effects of chronic exposure to iAs. High-performance liquid chromatography-inductively coupled plasma-mass ...

  15. Characterisation of chemical components for identifying historical Chinese textile dyes by ultra high performance liquid chromatography – photodiode array – electrospray ionisation mass spectrometer

    NARCIS (Netherlands)

    Han, J.; Wanrooij, J.; van Bommel, M.; Quye, A.

    2017-01-01

    This research makes the first attempt to apply Ultra High Performance Liquid Chromatography (UHPLC) coupled to both Photodiode Array detection (PDA) and Electrospray Ionisation Mass Spectrometer (ESI–MS) to the chemical characterisation of common textile dyes in ancient China. Three different

  16. Optimisation of high-performance liquid chromatography with diode array detection using an automatic peak tracking procedure based on augmented iterative target transformation factor analysis

    NARCIS (Netherlands)

    van Zomeren, Paul; Hoogvorst, A.; Coenegracht, P.M J; de Jong, G.J.

    2004-01-01

    An automated method for the optimisation of high-performance liquid chromatography is developed. First of all, the sample of interest is analysed with various eluent compositions. All obtained data are combined into one augmented data matrix. Subsequently, augmented iterative target transformation

  17. Analysis of Caffeic Acid Extraction From Ocimum gratissimum Linn. by High Performance Liquid Chromatography and its Effects on a Cervical Cancer Cell Line

    Directory of Open Access Journals (Sweden)

    Je-Chiuan Ye

    2010-09-01

    Conclusion: This paper shows that high performance liquid chromatography is a suitable analytical method for determining caffeic acid levels in O. gratissimum, Ju ZenTa, and several vegetable oils. Caffeic acid can suppress the proliferation of HeLa cells.

  18. Quantification of anthocyanins in commercial black currant juices by simple high-performance liquid chromatography. Investigation of their pH stability and antioxidative potency

    DEFF Research Database (Denmark)

    Nielsen, Inge Lise F.; Ravn-Haren, Gitte; Magnussen, Eva Loftin

    2003-01-01

    Quantitative determinations of the four black currant anthocyanins, cyanidin 3-O-beta-glucoside, cyanidin 3-O-beta-rutinoside, delphinidin 3-O-beta-glucoside, and delphinidin 3-O-beta-rutinoside, were achieved in black currant juices by a rapid and sensitive high-performance liquid chromatographi...

  19. Utilization of high performance liquid chromatography coupled to tandem mass spectrometry for characterization of 8-O-methylbostrycoidin production by species of the fungus Fusarium

    Science.gov (United States)

    The pigment, 8-O-methylbostrycoidin is a polyketide metabolite produced by multiple species of the fungus Fusarium that infects plant crops, including maize. A technique was developed for the analysis of 8-O-methylbostrycoidin by high performance liquid chromatography coupled to electrospray ionizat...

  20. Development of a new ultra-high performance liquid chromatography - tandem mass spectrometry method for determination of ambroxol hydrochloride in serum with pharmacokinetic application

    OpenAIRE

    Vujović Maja M.; Jokanović Milan; Nikolić Goran M.

    2016-01-01

    Ambroxol hydrochloride is an expectorant agent, successfully applied in mucolytic therapy for acute and chronic bronchopulmonary diseases. The drug regulates not only mucus secretion but also showed antioxidant, anti-inflammatory and local anesthetic properties. To supplement the pharmacokinetic and toxicological studies of ambroxol, a rapid ultra-high performance liquid chromatography-tandem mass spectrometry method for the quantitation of ambroxol in rabb...

  1. Comprehensive Two-dimensional Liquid Chromatography coupled to High Resolution Time of Flight Mass Spectrometry for Chemical Characterization of Sewage Treatment Plant Effluents

    NARCIS (Netherlands)

    Ouyang, X.; Leonards, P.E.G.; Legler, J.; van der Oost, R.; de Boer, J.; Lamoree, M.H.

    2015-01-01

    For the first time a comprehensive two-dimensional liquid chromatography (LC. ×. LC) system coupled with a high resolution time-of-flight mass spectrometer (HR-ToF MS) was developed and applied for analysis of emerging toxicants in wastewater effluent. The system was optimized and validated using

  2. Validation of a high-performance liquid chromatography/fluorescence detection method for the simultaneous quantification of fifteen polycyclic aromatic hydrocarbons

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Olsen, I L; Holst, E

    1991-01-01

    A high-performance liquid chromatography/fluorescence method using multiple wavelength shift for simultaneous quantification of different PAH compounds was developed. The new method was superior to the methods of DONG and GREENBERG [J. Liquid Chromatogr. 11, 1887-1905 (1988)] and WISE et al. [Pol...

  3. Determination of thromboxanes, leukotrienes and lipoxins using high-temperature capillary liquid chromatography-tandem mass spectrometry and on-line sample preparation

    DEFF Research Database (Denmark)

    Dahl, Sandra Rinne; Kleiveland, Charlotte Ramstad; Kassem, Moustapha

    2009-01-01

    culture supernatants was developed and validated. In the present method, a high temperature (70 degrees C) was used for the separation on the analytical column to obtain efficient chromatography of the thromboxanes. An on-line sample preparation was performed, where peptides/proteins contained...

  4. Investigation of drugs of abuse and relevant metabolites in Dutch sewage water by liquid chromatography coupled to high resolution mass spectrometry

    NARCIS (Netherlands)

    Bijlsma, L.; Emke, E.; Hernández, F.; de Voogt, P.

    2012-01-01

    An extensive study on the presence of illicit drugs and pharmaceuticals with potential for abuse in sewage waters was made for the first time in the Netherlands. A total number of 24 target drugs were investigated in influent and effluent wastewater using liquid chromatography coupled to a high

  5. Simultaneous determination of 13 carbohydrates using high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry.

    Science.gov (United States)

    Zhao, Dan; Feng, Feng; Yuan, Fei; Su, Jin; Cheng, Yan; Wu, Hanqiu; Song, Kun; Nie, Bo; Yu, Lian; Zhang, Feng

    2017-04-01

    A simple, accurate, and highly sensitive method was developed for the determination of 13 carbohydrates in polysaccharide of Spirulina platensis based on high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry. Samples were extracted with deionized water using ultrasonic-assisted extraction, and the ultrasound-assisted extraction conditions were optimized by Box-Behnken design. Then the extracted polysaccharide was hydrolyzed by adding 1 mol/L trifluoroacetic acid before determination by high-performance anion-exchange chromatography coupled with pulsed amperometric detection and confirmed by high-performance anion-exchange chromatography coupled with mass spectrometry. The high-performance anion-exchange chromatography coupled with pulsed amperometric detection method was performed on a CarboPac PA20 column by gradient elution using deionized water, 0.1 mol/L sodium hydroxide solution, and 0.4 mol/L sodium acetate solution. Excellent linearity was observed in the range of 0.05-10 mg/L. The average recoveries ranged from 80.7 to 121.7%. The limits of detection and limits of quantification for 13 carbohydrates were 0.02-0.10 and 0.2-1.2  μg/kg, respectively. The developed method has been successfully applied to ambient samples, and the results indicated that high-performance anion-exchange chromatography coupled with pulsed amperometric detection and mass spectrometry could provide a rapid and accurate method for the simultaneous determination of carbohydrates. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. [Determination of bisphenol A and alkyl phenols in canned food with high performance liquid chromatography--fluorescence].

    Science.gov (United States)

    Xiao, Jing; Shao, Bing; Wu, Yong-Ning; Wang, Zhu-Tian; Hou, Wei

    2007-11-01

    To establish a comprehensive analytical high performance liquid chromatography fluorescence detection (HPLC-FL) in detecting bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) in canned food sold in Beijing markets. BPA, NP and OP was extracted with methanol and dichloroacetamide and concentrated. The samples were purified on an solid extraction cartridges. The HPLC system consisted of Waters XTerra MS C18 column, a mixture of methanol and water as mobile phase and fluorescence detector with the excitation and emission wavelength at 225 nm and 310 nm respectively. The method established had a linear relationship, showing the detection limit of BPA, OP and NP being 0.5, 0.1 and 0.1 microg/kg in canned vegetable and instant noodle and 1, 0.5 and 0.5 microg/kg in canned fish and meat can, respectively. The recoveries of BPA, NP and OP were 74.9%-95.1% , 76.3%-103.6% and 72.1%-109.2%. The precision was 4.98%-11.2% , 2.35%-8.88% and 5.61%-12.3%, respectively. The method is simple with high sensitivity and selectivity, suitable for the determination of NP, OP and BPA in canned food.

  7. Analysis of anabolic androgenic steroids as sulfate conjugates using high performance liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Rzeppa, S; Heinrich, G; Hemmersbach, P

    2015-01-01

    Improvements in doping analysis can be effected by speeding up analysis time and extending the detection time. Therefore, direct detection of phase II conjugates of doping agents, especially anabolic androgenic steroids (AAS), is proposed. Besides direct detection of conjugates with glucuronic acid, the analysis of sulfate conjugates, which are usually not part of the routine doping control analysis, can be of high interest. Sulfate conjugates of methandienone and methyltestosterone metabolites have already been identified as long-term metabolites. This study presents the synthesis of sulfate conjugates of six commonly used AAS and their metabolites: trenbolone, nandrolone, boldenone, methenolone, mesterolone, and drostanolone. In the following these sulfate conjugates were used for development of a fast and easy analysis method based on sample preparation using solid phase extraction with a mixed-mode sorbent and detection by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Validation demonstrated the suitability of the method with regard to the criteria given by the technical documents of the World Anti-Doping Agency (WADA). In addition, suitability has been proven by successful detection of the synthesized sulfate conjugates in excretion urines and routine doping control samples. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Chemical composition separation of a propylene-ethylene random copolymer by high temperature solvent gradient interaction chromatography.

    Science.gov (United States)

    Liu, Yonggang; Phiri, Mohau Justice; Ndiripo, Anthony; Pasch, Harald

    2017-11-03

    A propylene-ethylene random copolymer was fractionated by preparative temperature rising elution fractionation (TREF). The structural heterogeneity of the bulk sample and its TREF fractions was studied by high temperature liquid chromatography with a solvent gradient elution from 1-decanol to 1,2,4-trichlorobenzene. HPLC alone cannot resolve those propylene-ethylene copolymers with high ethylene content in the bulk sample, due to their low weight fractions in the bulk sample and a small response factor of these components in the ELSD detector, as well as their broad chemical composition distribution. These components can only be detected after being separated and enriched by TREF followed by HPLC analysis. Chemical composition separations were achieved for TREF fractions with average ethylene contents between 2.1 and 22.0mol%, showing that copolymers with higher ethylene contents were adsorbed stronger in the Hypercarb column and eluted later. All TREF fractions, except the 40°C fraction, were relatively homogeneous in both molar mass and chemical composition. The 40°C fraction was rather broad in both molar mass and chemical composition distributions. 2D HPLC showed that the molar masses of the components containing more ethylene units were getting lower for the 40°C fraction. HPLC revealed and confirmed that co-crystallization influences the separation in TREF of the studied propylene-ethylene copolymer. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Simultaneous determination of six mycotoxins in peanut by high-performance liquid chromatography with a fluorescence detector.

    Science.gov (United States)

    Chen, Fangfang; Luan, Chuanlei; Wang, Lin; Wang, Shue; Shao, Lihua

    2017-04-01

    Mycotoxins, which may contaminate peanut and peanut products, are responsible for many diseases to humans. Aflatoxin B1 (AFB1), aflatoxin G1 (AFG1), aflatoxin B2 (AFB2), aflatoxin G2 (AFG2), ochratoxin A (OTA) and zearalenone (ZEN) are considered the most relevant groups of mycotoxins found in food. This work aimed to develop a high-performance liquid chromatography method with a fluorescence detector (HPLC-FLD) combined with dispersive liquid-liquid microextraction (DLLME) method for the simultaneous determination of the six mycotoxins in peanuts. The six mycotoxins were simultaneously determined under their best wavelength by means of changing wavelength. Under the optimum conditions, the linear ranges were 1-100 ng mL(-1) for AFB1, AFG1 and OTA, 0.3-30 ng mL(-1) for AFB2 and AFG2, 5-1000 ng mL(-1) for ZEN, with the correlation coefficient (R(2) ) of 0.9969-0.9997. Limits of detection (LODs) were 0.10, 0.10, 0.30, 0.03, 0.03 and 1.0 µg kg(-1) , respectively, and the mean recoveries were in the range of 83.1% to 99.3% with RSD mycotoxin. The proposed method was demonstrated to be simple, highly selective, accurate, reliable, and was successfully applied to simultaneously analyse the six mycotoxins in real peanut samples from China. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. Accurate screening for synthetic preservatives in beverage using high performance liquid chromatography with time-of-flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiuqin; Zhang Feng; Sun Yanyan; Yong Wei [Institute of Food Safety, Chinese Academy of Inspection and Quarantine, Jia 3, Gaobeidian North Road, Beijing 100025 (China); Chu Xiaogang [Institute of Food Safety, Chinese Academy of Inspection and Quarantine, Jia 3, Gaobeidian North Road, Beijing 100025 (China)], E-mail: lixq_sypu@yahoo.com; Fang Yanyan; Zweigenbaum, Jerry [Agilent Technologies, Inc., 2850 Centerville Road, Wilmington, Delaware (United States)

    2008-02-11

    In this study, liquid chromatography time-of-flight mass spectrometry (HPLC/TOF-MS) is applied to qualitation and quantitation of 18 synthetic preservatives in beverage. The identification by HPLC/TOF-MS is accomplished with the accurate mass (the subsequent generated empirical formula) of the protonated molecules [M + H]+ or the deprotonated molecules [M - H]-, along with the accurate mass of their main fragment ions. In order to obtain sufficient sensitivity for quantitation purposes (using the protonated or deprotonated molecule) and additional qualitative mass spectrum information provided by the fragments ions, segment program of fragmentor voltages is designed in positive and negative ion mode, respectively. Accurate mass measurements are highly useful in the complex sample analyses since they allow us to achieve a high degree of specificity, often needed when other interferents are present in the matrix. The mass accuracy typically obtained is routinely better than 3 ppm. The 18 compounds behave linearly in the 0.005-5.0 mg.kg{sup -1} concentration range, with correlation coefficient >0.996. The recoveries at the tested concentrations of 1.0 mg.kg{sup -1}-100 mg.kg{sup -1} are 81-106%, with coefficients of variation <7.5%. Limits of detection (LODs) range from 0.0005 to 0.05 mg.kg{sup -1}, which are far below the required maximum residue level (MRL) for these preservatives in foodstuff. The method is suitable for routine quantitative and qualitative analyses of synthetic preservatives in foodstuff.

  11. Separation of phenolic acids and flavonoids from Trollius chinensis Bunge by high speed counter-current chromatography.

    Science.gov (United States)

    Qin, Yanhua; Liang, Yizeng; Ren, Dabing; Qiu, Ximin; Li, Xi

    2015-09-15

    In this work, eleven compounds were successfully separated from Trollius chinensis Bunge by using a two-step high-speed counter-current chromatography (HSCCC) method. NRTL-SAC (nonrandom two-liquid segment activity coefficient) method, a newly developed solvent system selection strategy, was applied to screening the suitable biphasic liquid systems. Hexane/ethyl acetate/ethanol/water (3:7:3:7, v/v) solvent system was used in the first step, while the hexane/ethyl acetate/methanol/water (1:2:1:2, 1:4:1:4, 1:9:1:9, v/v) systems were employed in the second step. The chemical structures of the separated compounds were identified by UV, high resolution ESI-MS and MS/MS data. The separated compounds are 3,4-dihydroxyphenylethanol (1), vanillic acid (2), orientin (3), vitexin (4), veratric acid (5), 2″-O-(3‴, 4‴-dimethoxybenzoyl) orientin (6), 2″-O-feruloylorientin (7), 2″-O-feruloylvitexin (8), 2″-O-(2‴-methylbutyryl) vitexin (9), 2″-O-(2‴-methylbutyryl) isoswertiajaponin (10), 2″-O-(2‴-methylbutyryl) isoswertisin (11). The results demonstrate that HSCCC is a powerful tool for the separation of compounds from extremely complex samples. Copyright © 2015. Published by Elsevier B.V.

  12. Preparative isolation of anthocyanins from Japanese purple sweet potato (Ipomoea batatas L.) varieties by high-speed countercurrent chromatography.

    Science.gov (United States)

    Montilla, Elyana Cuevas; Hillebrand, Silke; Butschbach, Daniela; Baldermann, Susanne; Watanabe, Naoharu; Winterhalter, Peter

    2010-09-22

    Purple-fleshed sweet potatoes (Ipomoea batatas L.) contain a very complex anthocyanin profile due to the presence of several non-, mono-, and diacylated glucosides of cyanidin and peonidin. In this study, the anthocyanin composition of four Japanese purple sweet potato cultivars (Chiran Murasaki, Tanegashima Murasaki, Naka Murasaki, and Purple Sweet) were investigated by HPLC-DAD and ESI-MSn analyses. The HPLC chromatograms of the different cultivars show a remarkable variation of the two major pigments, cyanidin-3-(6''-caffeoylsophoroside)-5-glucoside and peonidin-3-(6''-caffeoylsophoroside)-5-glucoside, respectively. According to this, they can be categorized into two groups on the basis of the peonidin/cyanidin ratio: the cultivars Chiran Murasaki and Purple Sweet showed a high content of peonidin derivatives (peonidin type), whereas the varieties Tanegashima Murasaki and Naka Murasaki were classified as cyanidin types. By means of high-speed countercurrent chromatography (HSCCC) the nonacylated 3-sophoroside-5-glucoside of cyanidin was isolated on a preparative scale. Furthermore, it was possible to isolate the monoacylated cyanidin-3-(6''-caffeoylsophoroside)-5-glucoside as well as three diacylated major pigments, cyanidin-3-(6'',6'''-dicaffeoylsophoroside)-5-glucoside, cyanidin-3-(6''-caffeoyl-6'''-p-hydroxy-benzoylsophoroside)-5-glucoside, and peonidin-3-(6''-caffeoyl-6'''-p-hydroxybenzoyl-sophoroside)-5-glucoside. The purity and identity of the so-obtained pigments were confirmed by NMR measurements.

  13. Comprehensive analysis of airborne pesticides using hard cap espresso extraction-liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    López, Antonio; Coscollà, Clara; Yusà, Vicent; Armenta, Sergio; de la Guardia, Miguel; Esteve-Turrillas, Francesc A

    2017-07-14

    A hard cap espresso extraction procedure has been developed to recover airborne pesticides in particulate matter trapped in filters. This extraction step was made for 20s at 72°C and 19bar using 50mL of 20% (v/v) acetonitrile in water. After that, based on NaCl salting out, extracts were concentrated 22 times and analysed by ultra-high performance liquid chromatography - high resolution mass spectrometry. 35 pesticides were evaluated, as a proof of concept, being validated the whole methodology and compared the extraction method with that based on microwave assisted extraction for 20min. In short, the method avoids cross-contamination of samples, it is relatively fast and consumes only 10mL acetonitrile and 8g NaCl per sample; thus, offering a low cost and green alternatively to available methods based on pressurized solvent extraction or microwave-assisted treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. High-performance liquid chromatography and derivative spectrophotometry for simultaneous determination of pravastatin and fenofibrate in the dosage form.

    Science.gov (United States)

    Hefnawy, Mohamed M; Mohamed, Mostafa S; Abounassif, Mohammed A; Alanazi, Amer M; Mostafa, Gamal A E

    2014-12-01

    High performance liquid chromatography (HPLC) and second-order derivative spectrophotometry have been used for simultaneous determination of pravastatin (PS) and fenofibrate (FF) in pharmaceutical formulations. HPLC separation was performed on a phenyl HYPERSIL C18 column (125 mm × 4.6 mm i.d., 5 μm particle diameter) in the isocratic mode using a mobile phase acetonitrile/0.1 % diethyl amine (50:50, V/V, pH 4.5) pumped at a flow rate of 1.0 mL min-1. Measurement was made at 240 nm. Both drugs were well resolved on the stationary phase, with retention times of 2.15 and 5.79 min for PS and FF, respectively. Calibration curves were linear (R = 0.999 for PS and 0.996 for FF) in the concentration range of 5-50 and 20-200 µg mL-1 for PS and FF, respectively. Pravastatin and fenofibrate were quantitated in combined preparations also using the second-order derivative response at 237.6 and 295.1 nm for PS and FF, respectively. Calibration curves were linear, with the correlation coefficient R = 0.999 for pravastatin and fenofibrate, in the concentration range of 5-20 and 3-20 µg mL-1 for PS and FF, respectively. Both methods were fully validated and compared, the results confirmed that they were highly suitable for their intended purpose.

  15. Molecularly imprinted solid-phase extraction for the selective determination of valnemulin in feeds with high performance liquid chromatography.

    Science.gov (United States)

    Guo, Hongbin; Liu, Kaiyong; Liu, Yahong; Fang, Binghu; Liu, Min; He, Limin; Zeng, Zhenling

    2011-01-15

    A simple, sensitive and reproducible high performance liquid chromatographic method was developed for determining valnemulin in feeds. Feed samples were extracted with ethyl acetate under alkaline condition, cleaned up by molecularly imprinted solid-phase extraction, and analyzed by high performance liquid chromatography with ultraviolet detection. The characteristics of the synthesized polymer were evaluated and the loading capacity of the polymer was about 1000 μg analyte/g imprinted polymer. The new procedure for the feed sample cleanup using the prepared polymer cartridge gave higher recoveries and fewer matrix interferences. The assay exhibited a linear dynamic range of 5.0-200 mg kg(-1) with the correlation coefficient above 0.9993. Recoveries of valnemulin from feed samples spiked at 5.0, 20 and 50 mg kg(-1) ranged between 76.0% and 94.4% with relative standard deviations of less than 9%. The limit of detection for valnemulin in feeds was 1 mg kg(-1). Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Comparison of UV spectrophotometry and high performance liquid chromatography methods for the determination of repaglinide in tablets.

    Science.gov (United States)

    Dhole, Seema M; Khedekar, Pramod B; Amnerkar, Nikhil D

    2012-07-01

    Repaglinide is a miglitinide class of antidiabetic drug used for the treatment of type 2 diabetes mellitus. A fast and reliable method for the determination of repaglinide was highly desirable to support formulation screening and quality control. UV spectrophotometric and reversed-phase high performance liquid chromatography (RP-HPLC) methods were developed for determination of repaglinide in the tablet dosage form. The UV spectrum recorded between 200 400 nm using methanol as solvent and the wavelength 241 nm was selected for the determination of repaglinide. RP-HPLC analysis was carried out using Agilent TC-C18 (2) column and mobile phase composed of methanol and water (80:20 v/v, pH adjusted to 3.5 with orthophosphoric acid) at a flow rate of 1.0 ml/min. Parameters such as linearity, precision, accuracy, recovery, specificity and ruggedness are studied as reported in the International Conference on Harmonization (ICH) guidelines. The developed methods illustrated excellent linearity (r(2) > 0.999) in the concentration range of 5-30 μg/ml and 5-50 μg/ml for UV spectrophotometric and HPLC methods, respectively. Precision (%R.S.D UV spectrophotometric method and 99.71-100.25% for HPLC method which shows accuracy of the methods. The developed methods were found to be reliable, simple, fast, accurate and successfully used for the quality control of repaglinide as a bulk drug and in pharmaceutical formulations.

  17. Fast log P determination by ultra-high-pressure liquid chromatography coupled with UV and mass spectrometry detections.

    Science.gov (United States)

    Henchoz, Yveline; Guillarme, Davy; Martel, Sophie; Rudaz, Serge; Veuthey, Jean-Luc; Carrupt, Pierre-Alain

    2009-08-01

    Ultra-high-pressure liquid chromatography (UHPLC) systems able to work with columns packed with sub-2 microm particles offer very fast methods to determine the lipophilicity of new chemical entities. The careful development of the most suitable experimental conditions presented here will help medicinal chemists for high-throughput screening (HTS) log P(oct) measurements. The approach was optimized using a well-balanced set of 38 model compounds and a series of 28 basic compounds such as beta-blockers, local anesthetics, piperazines, clonidine, and derivatives. Different organic modifiers and hybrid stationary phases packed with 1.7-microm particles were evaluated in isocratic as well as gradient modes, and the advantages and limitations of tested conditions pointed out. The UHPLC approach offered a significant enhancement over the classical HPLC methods, by a factor 50 in the lipophilicity determination throughput. The hyphenation of UHPLC with MS detection allowed a further increase in the throughput. Data and results reported herein prove that the UHPLC-MS method can represent a progress in the HTS-measurement of lipophilicity due to its speed (at least a factor of 500 with respect to HPLC approaches) and to an extended field of application.

  18. Quantitative analysis of cytokinins in plants by high performance liquid chromatography: electronspray ionization ion trap mass spectrometry.

    Science.gov (United States)

    Chen, Weiqi; Gai, Ying; Liu, Shichang; Wang, Renxiao; Jiang, Xiangning

    2010-10-01

    The present paper introduces a highly sensitive and selective method for simultaneous quantification of 12 cytokinins (free form and their conjugates). The method includes a protocol of extraction with methanol/water/formic acid (15/4/1, v/v/v) to the micro-scale samples, pre-purification with solid phase extraction (SPE) cartridges of the extracts, separation with a high performance liquid chromatography (HPLC) and detection by an electrospray ionization ion trap mass spectrometry (ESI-Ion trap-MS) system in a consecutive ion monitoring (CRM) mode at the three stage fragmentation of mass spectrometry (MS(3) ). The lowest detection level of the cytokinins of the method reaches 0.1-2.0 pg with a very wide range of linear regression from 1-512 pg, at the coefficient factors of 0.98-0.99. The feasibility of this method has been proven in the application of the method to the analysis of the trace-amount contents of cytokinins in the micro-scale samples of various types of plant materials, such as aerial parts of rice and poplar leaves etc. 12 endogenous cytokinins had been identified and quantified in the plant tissues, with an acceptable relatively higher recovery rate from 40% to 70%. © 2010 Institute of Botany, Chinese Academy of Sciences.

  19. [Monolithic molecularly imprinted column-high performance liquid chromatography for enrichment and determination of trace cytokinins in plant samples].

    Science.gov (United States)

    Sun, Lin; Du, Fuyou; Ruan, Guihua; Huang, Yijia

    2013-04-01

    A method based on monolithic molecularly imprinted polymer enrichment combining with high performance liquid chromatography (mMIP-HPLC) detection was developed for the selective determination of trace cytokinins (CTKs) in plant samples. Monolithic molecularly imprinted polymer (mMIP) column was prepared in stainless steel tube by using kinetin as the template, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, and toluene-dodecanol as the porogenic solvents. Compared with non-imprinted polymer (NIP) monolith, the prepared mMIP exhibited selective separation ability, good reproducibility and reusability, and high extraction efficiency in the separation and enrichment of the four CTKs. Under the optimized experimental conditions, mean recoveries were 91.9%, 80.0%, 87.5% and 50.2% for kinetin (K), kinetin glucoside (KR) , trans-zeatin (tZ) and meta-topolin (mT), respectively, with the corresponding RSDs less than 11.8%. The proposed mMIP-HPLC method was successfully applied in the separation and determination of the four cytokinins in different plant samples

  20. Monitoring gradient profile on-line in micro- and nano-high performance liquid chromatography using conductivity detection.

    Science.gov (United States)

    Zhang, Min; Chen, Apeng; Lu, Joann J; Cao, Chengxi; Liu, Shaorong

    2016-08-19

    In micro- or nano-flow high performance liquid chromatography (HPLC), flow-splitters and gradient elutions are commonly used for reverse phase HPLC separations. When a flow splitter was used at a high split-ratio (e.g., 1000:1 or higher), the actual gradient may deviate away from the programmed gradient. Sometimes, mobile phase concentrations can deviate by as much as 5%. In this work, we noticed that the conductivity (σ) of a gradient decreased with the increasing organic-solvent fraction (φ). Based on the relationship between σ and φ, a method was developed for monitoring gradient profile on-line to record any deviations in these HPLC systems. The conductivity could be measured by a traditional conductivity detector or a capacitively coupled contactless conductivity detector (C(4)D). The method was applied for assessing the performance of an electroosmotic pump (EOP) based nano-HPLC. We also observed that σ value of the gradient changed with system pressure; a=0.0175ΔP (R(2)=0.964), where a is the percentage of the conductivity increase and ΔP is the system pressure in bar. This effect was also investigated. Copyright © 2016. Published by Elsevier B.V.

  1. High-performance liquid chromatography and derivative spectrophotometry for simultaneous determination of pravastatin and fenofibrate in the dosage form

    Directory of Open Access Journals (Sweden)

    Hefnawy Mohamed M.

    2014-12-01

    Full Text Available High performance liquid chromatography (HPLC and second-order derivative spectrophotometry have been used for simultaneous determination of pravastatin (PS and fenofibrate (FF in pharmaceutical formulations. HPLC separation was performed on a phenyl HYPERSIL C18 column (125 mm × 4.6 mm i.d., 5 μm particle diameter in the isocratic mode using a mobile phase acetonitrile/0.1 % diethyl amine (50:50, V/V, pH 4.5 pumped at a flow rate of 1.0 mL min-1. Measurement was made at 240 nm. Both drugs were well resolved on the stationary phase, with retention times of 2.15 and 5.79 min for PS and FF, respectively. Calibration curves were linear (R = 0.999 for PS and 0.996 for FF in the concentration range of 5-50 and 20-200 µg mL-1 for PS and FF, respectively. Pravastatin and fenofibrate were quantitated in combined preparations also using the second-order derivative response at 237.6 and 295.1 nm for PS and FF, respectively. Calibration curves were linear, with the correlation coefficient R = 0.999 for pravastatin and fenofibrate, in the concentration range of 5-20 and 3-20 µg mL-1 for PS and FF, respectively. Both methods were fully validated and compared, the results confirmed that they were highly suitable for their intended purpose.

  2. High-performance liquid chromatography for the quantitative determination of the urinary metabolites of toluene, xylene, and styrene

    Energy Technology Data Exchange (ETDEWEB)

    Poggi, G.; Giusiani, M.; Palagi, U.; Paggiaro, P.L.; Loi, A.M.; Dazzi, F.; Siclari, C.; Baschieri, L.

    1982-01-01

    A new high-pressure liquid chromatography (HPLC) method for simultaneous quantitative determination of the urinary metabolites of toluene, m-xylene, and styrene (hippuric acid, m-methylhippuric acid, phenylglyoxylic acid, mandelic acid) is described. The extraction procedure was performed on acidified urines, after addition of 4-hydroxybenzoic acid as internal standard, using a butylchloride/isopropanol mixture and drying 0.5 ml of the organic layer under nitrogen flow. The residue obtained was dissolved in 0.1 ml water/acetonitrile and 5 microliters were injected into an HPLC apparatus equipped with a 0.26 X 25 cm HC ODS SIL X column. Absorbance measures were performed at 225 nm throughout the investigation. All metabolites were clearly separated in a short time (12 min) and the amounts of other urinary compounds affecting the analysis were so small that the measurement of low concentrations of the urinary metabolites could be easily performed. Linear calibration curves were obtained from 0.1 to 3 mg/ml and a correlation coefficient greater than 0.99 was found between concentrations of the standards and areas of the peaks. Statistical analysis confirms that this method, which has a high reproducibility, is simple, reliable, and useful for the biologic monitoring of industrial exposure to aromatic compounds.

  3. High-performance liquid chromatography for the quantitative determination of the urinary metabolites of toluene, xylene, and styrene

    Energy Technology Data Exchange (ETDEWEB)

    Poggi, G.; Giusiani, M.; Palagi, U.; Paggiaro, P.L.; Loi, A.M.; Dazzi, F.; Siclari, C.; Baschieri, L.

    1982-04-01

    A new high-pressure liquid chromatography (HPLC) method for simultaneous quantitative determination of the urinary metabolites of toluene, m-xylene, and styrene (hippuric acid, m-methylhippuric acid, phenylglyoxylic acid, mandelic acid) is described. The extraction procedure was performed on acidified urines, after addition of 4-hydroxybenzoic acid as internal standard, using a butylchloride/isopropanol mixture and drying 0.5 ml of the organic layer under nitrogen flow. The residue obtained was dissolved in 0.1 ml water/acetonitrile and 5 ..mu..l were injected into an HPLC apparatus equipped with a 0.26 x 25 cm HC ODS SIL X column. Absorbance measures were performed at 225 nm throughout the investigation. All metabolites were clearly separated in a short time (12 min) and the amounts of other urinary compounds affecting the analysis were so small that the measurement of low concentrations of the urinary metabolites could be easily performed. Linear calibration curves were obtained from 0.1 to 3 mg/ml and a correlation coefficient greater than 0.99 was found between concentrations of the standards and areas of the peaks. Statistical analysis confirms that this method, which has a high reproducibility, is simple, reliable, and useful for the biologic monitoring of industrial exposure to aromatic compounds.

  4. [Identification of triacylglycerols in coix oil by high performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry].

    Science.gov (United States)

    Xiang, Zhi-Min; Zhu, Ming; Chen, Bi-Lian; Chen, Yong

    2005-09-01

    To identify triacylglycerols in coix oil. High performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry was used for identification. The experiment was operated under the conditions: spray voltage at 3 000 V, capillary temperature at 250 degrees C, APCI vaporizer temperature at 400 degrees C, and corona current of 4 microA. Sheath gas pressure (high purity liquid nitrogen) was 35 kPa. Mass spectra were obtained over the m/e range of 300 to 900 amu, scan duration of 1s and Q1 peak width at 0.7. The stationary phase was Zorbax Extend C18 column (4.6 mm x 250 mm, 5 microm). The mobile phase: dichloromethane-acetonitrile (35:65), flow rate: 1 mL x min(-1); column temperature: 25 degrees C. 12 triacylglycerols were identified by HPLC-MS method. The result can be used to identify the components in a fingerprint chromatogram of coix oil and its related injection product.

  5. Preconcentration of synthetic phenolic antioxidants by using magnetic zeolites derived with carboxylatocalix[4]arenes combined with high performance liquid chromatography.

    Science.gov (United States)

    Zhou, Shaoyan; Li, Zheng; Lv, Xueju; Hu, Bin; Jia, Qiong

    2015-09-07

    Here, we synthesized a novel organic-inorganic hybrid material combining carboxylatocalix[4]arenes and magnetic zeolites by covalent bonding. The complex was characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction spectrometry, thermogravimetric analysis/differential thermal gravity analysis, and by using an X-ray photoelectron spectrometer and a vibrating sample magnetometer. The resulting magnetic composite was employed as a solid phase adsorbent to separate and preconcentrate synthetic phenolic antioxidants. Various interactions between the targets and the adsorbent contributed to the adsorption efficiency including hydrophobic interaction, hydrogen-bond interaction, and π-π complexation. The superparamagnetic participation in the process of synthesizing zeolites made the separation process of adsorbent from solutions convenient by an external magnetic field. Taking advantage of this property, this adsorbent could be recycled more than 30 times. The concentrations of the preconcentrated SPAs were determined directly by high-performance liquid chromatography. Various experimental parameters were optimized, according to which the method was evaluated. Finally, the prepared magnetic zeolite@carboxylatocalix[4]arene was successfully applied to identify synthetic phenolic antioxidants from juice and infant milk powder samples with high enrichment factors in the range of 41.9-92.5. The magnetic materials allowed rapid and simple preconcentration, implying their potential in the field of adsorption.

  6. Phytochemical profile and nutraceutical potential of chia seeds (Salvia hispanica L.) by ultra high performance liquid chromatography.

    Science.gov (United States)

    Martínez-Cruz, Oliviert; Paredes-López, Octavio

    2014-06-13

    Chia seeds (Salvia hispanica) were analyzed for total phenolic compounds, antioxidant activity, and quantification of phenolic acids and isoflavones by ultra high performance liquid chromatography (UHPLC), in order to obtain a phenolic phytochemical profile. The total phenolic concentration was 1.8-fold higher than previous reports and the antioxidant activity using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical assay showed 68.83% inhibition, which was higher than the values reported previously for chia and different plant foods. Additionally, a simple, reproducible and rapid UHPLC method was proposed for the analysis of phenolic acids and isoflavones in chia. The method demonstrated to perform well with regard to linearity, limits of detection and quantification, precision, accuracy, and sensitivity. The detection limits ranged from 0.05 to 0.4ng/mL and the recovery percentage from 23.62 to 162.48%. With this method the major compounds identified and quantified were: rosmarinic acid 0.92, protocatechuic ethyl ester 0.74, caffeic acid 0.02, gallic acid 0.01, and daidzin 0.006mg/g seed. In brief, this study demonstrates that chia could be considered a seed with high antioxidant capacity and novel isoflavone source that can be incorporated in human diet. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Prototyping of thermoplastic microfluidic chips and their application in high-performance liquid chromatography separations of small molecules.

    Science.gov (United States)

    Wouters, Sam; De Vos, Jelle; Dores-Sousa, José Luís; Wouters, Bert; Desmet, Gert; Eeltink, Sebastiaan

    2017-11-10

    The present paper discusses practical aspects of prototyping of microfluidic chips using cyclic olefin copolymer as substrate and the application in high-performance liquid chromatography. The developed chips feature a 60mm long straight separation channel with circular cross section (500μm i.d.) that was created using a micromilling robot. To irreversibly seal the top and bottom chip substrates, a solvent-vapor-assisted bonding approach was optimized, allowing to approximate the ideal circular channel geometry. Four different approaches to establish the micro-to-macro interface were pursued. The average burst pressure of the microfluidic chips in combination with an encasing holder was established at 38MPa and the maximum burst pressure was 47MPa, which is believed to be the highest ever report for these polymer-based microfluidic chips. Porous polymer monolithic frits were synthesized in-situ via UV-initiated polymerization and their locations were spatially controlled by the application of a photomask. Next, high-pressure slurry packing was performed to introduce 3μm silica reversed-phase particles as the stationary phase in the separation channel. Finally, the application of the chip technology is demonstrated for the separation of alkyl phenones in gradient mode yielding baseline peak widths of 6s by applying a steep gradient of 1.8min at a flow rate of 10μL/min. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Design of high productivity antibody capture by protein A chromatography using an integrated experimental and modeling approach.

    Science.gov (United States)

    Ng, Candy K S; Osuna-Sanchez, Hector; Valéry, Eric; Sørensen, Eva; Bracewell, Daniel G

    2012-06-15

    An integrated experimental and modeling approach for the design of high productivity protein A chromatography is presented to maximize productivity in bioproduct manufacture. The approach consists of four steps: (1) small-scale experimentation, (2) model parameter estimation, (3) productivity optimization and (4) model validation with process verification. The integrated use of process experimentation and modeling enables fewer experiments to be performed, and thus minimizes the time and materials required in order to gain process understanding, which is of key importance during process development. The application of the approach is demonstrated for the capture of antibody by a novel silica-based high performance protein A adsorbent named AbSolute. In the example, a series of pulse injections and breakthrough experiments were performed to develop a lumped parameter model, which was then used to find the best design that optimizes the productivity of a batch protein A chromatographic process for human IgG capture. An optimum productivity of 2.9 kg L⁻¹ day⁻¹ for a column of 5mm diameter and 8.5 cm length was predicted, and subsequently verified experimentally, completing the whole process design approach in only 75 person-hours (or approximately 2 weeks). Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Novel approaches in analysis of Fusarium mycotoxins in cereals employing ultra performance liquid chromatography coupled with high resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zachariasova, M.; Lacina, O.; Malachova, A.; Kostelanska, M.; Poustka, J. [Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic); Godula, M. [Thermo Fisher Scientific, Czech Republic, Slunecna 27, 100 00 Prague 10 (Czech Republic); Hajslova, J., E-mail: jana.hajslova@vscht.cz [Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Food Chemistry and Analysis, Technicka 3, 166 28 Prague 6 (Czech Republic)

    2010-03-03

    Rapid, simple and cost-effective analytical methods with performance characteristics matching regulatory requirements are needed for effective control of occurrence of Fusarium toxins in cereals and cereal-based products to which they might be transferred during processing. Within this study, two alternative approaches enabling retrospective data analysis and identification of unknown signals in sample extracts have been implemented and validated for determination of 11 major Fusarium toxins. In both cases, ultra-high performance liquid chromatography (U-HPLC) coupled with high resolution mass spectrometry (HR MS) was employed. {sup 13}C isotopically labeled surrogates as well as matrix-matched standards were employed for quantification. As far as time of flight mass analyzer (TOF-MS) was a detection tool, the use of modified QuEChERS (quick easy cheap effective rugged and safe) sample preparation procedure, widely employed in multi-pesticides residue analysis, was shown as an optimal approach to obtain low detection limits. The second challenging alternative, enabling direct analysis of crude extract, was the use of mass analyzer based on Orbitrap technology. In addition to demonstration of full compliance of the new methods with Commission Regulation (EC) No. 401/2006, also their potential to be used for confirmatory purposes according to Commission Decision 2002/657/EC has been critically assessed.

  10. Determination of carbamate pesticides using micro-solid-phase extraction combined with high-performance liquid chromatography.

    Science.gov (United States)

    Basheer, Chanbasha; Alnedhary, Anass Ali; Rao, B S Madhava; Lee, Hian Kee

    2009-01-09

    We describe a simple and sensitive porous polypropylene membrane-protected micro-solid-phase extraction (mu-SPE) approach for the sample preparation and determination of carbamate pesticides in soil samples by high-performance liquid chromatography. The mu-SPE device consisted of C(18) sorbent held within a porous polypropylene envelope. In order to achieve optimum performance, several extraction parameters were optimized. Under the most favorable conditions, the extraction efficiency of the mu-SPE was very high, with detection limits in the range of 0.01-0.40 ng g(-1). This is more than two orders of magnitude lower than the limits obtained by the United States Environmental Protection Agency Methods 8321A and 8318. A linear relationship was obtained for each analyte in the range of 2 and 200 ng g(-1). The relative standard deviation for the analysis of aged soil samples spiked at 5 ng g(-1) was experiments was satisfactory (relative standard deviations ranged from 4 to 11%), indicating that the method is reliable for routine environmental analysis.

  11. Simultaneous determination of methamphetamine and its metabolite, amphetamine, in urine using a high performance liquid chromatography column-switching method.

    Science.gov (United States)

    Kumihashi, Mitsuru; Ameno, Kiyoshi; Shibayama, Takayuki; Suga, Keisuke; Miyauchi, Hiroshi; Jamal, Mostofa; Wang, Weihuan; Uekita, Ikuo; Ijiri, Iwao

    2007-01-01

    We describe here a simple, precise, and highly sensitive method for the simultaneous determination of methamphetamine (MA) and amphetamine (AM) in urine using a high performance liquid chromatography (HPLC) column-switching method. A PK-2A (Shodex) column was used for extraction and deproteinization, and a CAPCELL PAK SCX semi-micro, polymer-coated cation-exchange column was employed for separation. The urine sample was mixed with an equal volume of borate buffer (0.1M, pH 9.4), and then 100 microl of the mixture was injected into the HPLC column. The column was switched for 6 min, and then 10 min later detection was performed at 210 nm. Recovery yields of the MA and AM spiked in the urine were 93.0-100.4% with a coefficient of variation of less than 1%. The calibration curves of MA and AM were in the range of 0.1-10 microg/ml with good linearity (r(2)=0.999), with the limit of qualification being 0.005 microg/ml. This method of using HPLC with column-switching can be used for both qualification and quantification of MA and its metabolite, AM, in urine, especially in forensic cases.

  12. Determination of sulfonamides in butter samples by ionic liquid magnetic bar liquid-phase microextraction high-performance liquid chromatography.

    Science.gov (United States)

    Wu, Lijie; Song, Ying; Hu, Mingzhu; Xu, Xu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

    2015-01-01

    A novel, simple, and environmentally friendly pretreatment method, ionic liquid magnetic bar liquid-phase microextraction, was developed for the determination of sulfonamides in butter samples by high-performance liquid chromatography. The ionic liquid magnetic bar was prepared by inserting a stainless steel wire into the hollow of a hollow fiber and immobilizing ionic liquid in the micropores of the hollow fiber. In the extraction process, the ionic liquid magnetic bars were used to stir the mixture of sample and extraction solvent and enrich the sulfonamides in the mixture. After extraction, the analyte-adsorbed ionic liquid magnetic bars were readily isolated with a magnet from the extraction system. It is notable that the present method was environmentally friendly since water and only several microliters of ionic liquid were used in the whole extraction process. Several parameters affecting the extraction efficiency were investigated and optimized, including the type of ionic liquid, sample-to-extraction solvent ratio, the number of ionic liquid magnetic bars, extraction temperature, extraction time, salt concentration, stirring speed, pH of the extraction solvent, and desorption conditions. The recoveries were in the range of 73.25-103.85 % and the relative standard deviations were lower than 6.84 %. The experiment results indicated that the present method was effective for the extraction of sulfonamides in high-fat content samples.

  13. Determination of potato glycoalkaloids using high-pressure liquid chromatography-electrospray ionisation/mass spectrometry.

    Science.gov (United States)

    Matsuda, Fumio; Morino, Keiko; Miyazawa, Haruna; Miyashita, Masahiro; Miyagawa, Hisashi

    2004-01-01

    A method for quantifying two toxic glycoalkaloids, alpha-solanine and alpha-chaconine, in potato (Solanum tuberosum) tuber tissue was developed using HPLC-electrospray ionisation (ESI)/MS. Potato samples were extracted with 5% aqueous acetic acid, and the extracts were subjected directly to HPLC-ESI/MS after filtration. By determining the intensities of the protonated molecules of alpha-solanine (m/z 868) and alpha-chaconine (m/z 852) using selected ion monitoring (positive ion mode), a sensitive assay was attained with detection limits of 38 and 14 ppb for the two glycoalkaloids, respectively. The high sensitivity and selectivity of MS detection effectively reduced the time of analysis thus enabling a high throughput assay of glycoalkaloids in potato tubers.

  14. An activated medium with high durability and low nonspecific adsorption: application to protein A chromatography.

    Science.gov (United States)

    Maeno, Katsuyuki; Hirayama, Aya; Sakuma, Kenichi; Miyazawa, Kazuyuki

    2011-02-01

    Activated media allow the user to easily synthesize a variety of affinity media. We have developed a novel activated medium based on porous silica modified with phosphorylcholine (PC) and N-hydroxysuccinimide (NHS) groups for the purpose of high-throughput purification and reducing nonspecific protein adsorption. The PC groups function as suppressors of nonspecific protein adsorption, whereas the NHS groups are able to covalently bind to the primary amino groups of ligands. Because protein A affinity medium is the most frequently used affinity medium, we prepared protein A media in which a recombinant protein A was bound to the NHS groups of the activated media and evaluated its utility. After optimizing various factors in the synthetic process, the resultant protein A medium showed improved durability at a high flow rate over 300 purification cycles and reduced nonspecific protein adsorption compared with commercially available protein A media. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Monitoring haloperidol exposure in body fluids and hair of children by liquid chromatography-high-resolution mass spectrometry.

    Science.gov (United States)

    Favretto, Donata; Stocchero, Giulia; Nalesso, Alessandro; Vogliardi, Susanna; Boscolo-Berto, Rafael; Montisci, Massimo; Ferrara, Santo D

    2013-08-01

    Haloperidol, 4-[4-(4-chlorophenyl)-4-hydroxy-1-piperidinyl]-1-(4-fluorophenyl)-1-butanone (HP), one of the most widely used antipsychotics in the treatment of schizophrenia, mania, and other psychiatric disorders, is frequently encountered in cases of unintentional pediatric intoxication because the ingestion of a small amount can cause significant toxic effects in children. For monitoring HP in suspected ingestions, a liquid chromatography-high-resolution mass spectrometry method has been developed and validated in urine, blood, and hair samples. The analyte was extracted from 1 mL blood or urine by liquid/liquid extraction and from 5 mg of hair by micropulverized extraction; gradient elution on an Atlantis T3 column was realized using HP-d4 as an internal standard. Positive ion electrospray ionization and high-resolution mass spectrometry determination were performed in an Orbitrap mass spectrometer. The method exhibited a r > 0.999 in the studied ranges (0.1-50 ng/mL in urine and blood and 0.1-50 ng/mg in hair) and a limit of quantification of 0.1 ng/mL for urine and blood and 0.1 ng/mg for hair; intra-assay and interassay relative SDs were always more than 18%. The method was applied to determine haloperidol in 3 children who were admitted to emergency departments. HP concentrations ranged from 2 to 21 ng/mL in urine, from not detected to 4.9 ng/mL in blood, and from 0.37 to 0.73 ng/mg in hair samples. The utilization of high-resolution/high-accuracy mass spectrometry in full scan mode allowed the identification of HP metabolites in urine and blood, thus unequivocally documenting the exposure to the drug. HP metabolites were structurally characterized by high-resolution multiple mass spectrometry. For the first time, a HP metabolite was detected in hair.

  16. An efficient liquid chromatography-high resolution mass spectrometry approach for the optimization of the metabolic stability of therapeutic peptides.

    Science.gov (United States)

    Esposito, Simone; Mele, Riccardo; Ingenito, Raffaele; Bianchi, Elisabetta; Bonelli, Fabio; Monteagudo, Edith; Orsatti, Laura

    2017-04-01

    In drug discovery, there is increasing interest in peptides as therapeutic agents due to several appealing characteristics that are typical of this class of compounds, including high target affinity, excellent selectivity, and low toxicity. However, peptides usually present also some challenging ADME (absorption, distribution, metabolism, and excretion) issues such as limited metabolic stability, poor oral bioavailability, and short half-lives. In this context, early preclinical in vitro studies such as plasma metabolic stability assays are crucial to improve developability of a peptidic drug. In order to speed up the optimization of peptide metabolic stability, a strategy was developed for the integrated semi-quantitative determination of metabolic stability of peptides and qualitative identification/structural elucidation of their metabolites in preclinical plasma metabolic stability studies using liquid chromatography-high-resolution Orbitrap™ mass spectrometry (LC-HRMS). Sample preparation was based on protein precipitation: experimental conditions were optimized after evaluating and comparing different organic solvents in order to obtain an adequate extraction of the parent peptides and their metabolites and to minimize matrix effect. Peptides and their metabolites were analyzed by reverse-phase liquid chromatography: a template gradient (total run time, 6 min) was created to allow retention and good peak shape for peptides of different polarity and isoelectric points. Three LC columns were selected to be systematically evaluated for each series of peptides. Targeted and untargeted HRMS data were simultaneously acquired in positive full scan + data-dependent MS/MS acquisition mode, and then processed to calculate plasma half-life and to identify the major cleavage sites, this latter by using the software Biopharma Finder™. Finally, as an example of the application of this workflow, a study that shows the plasma stability improvement of a series of

  17. Determination of polycyclic aromatic hydrocarbons in coal combustion gas using high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, N. [Ishikawajima Harima Heavy Industry Co Ltd, Tokyo (Japan). Research Institution

    2002-11-01

    The study describes a sampling and analysis procedure for polycyclic aromatic hydrocarbons (PAH) at high temperatures in flue gas. Particulate matter sampling was used in conjunction with gas phase sampling. Particulates were collected on quartz fiber filter heated at the same temperature as flue gas. Vaporous PAHs not retained by the filter were cooled at 55{sup o}C and trapped from the gas phase on Tenax-GC polymer beads of 10 g. The sample volume was about 1 m{sup 3}. Tenax-GC has demonstrated high collection efficiency for benzo(a)pyrene (B(a)P) generated at 375{sup o}C under a stream of nitrogen. PAH were extracted with n-pentane for 4 h by a continuous PAH extractor. It demonstrated 99% extraction efficiency for B(a)P spiked on the adsorbent and it was more effective than Soxhlet extraction. The extracts were concentrated to 1 ml of n-pentane in a Kuderna Danish evaporator. Qualitative and quantitative analysis of the extracts were performed by high performance liquid chromatograph (HPLC) with ultraviolet/fluorescence detection. Eight PAH (3,4,5,6-dibenzocarbazole, phenanthrene, anthracene, fluoranthene, pyrene, 2-methylanthracene, benz(a)anthracene, benzo(a)pyrene) were determined in coal combustion gas on reducing NOx procedures. It was demonstrated that the tendency to reduce NOx levels leads to an increase in the PAH present. Moreover total concentration of four PAH (phenanthrene, fluoranthene, pyrene, benzo(a)pyrene) in this study is satisfactory agreement with those measured in the emissions of coal-fired power stations in the literature.

  18. Determination of Duloxetine and Its Major Metabolites in Rabbit Plasma by High-Performance Liquid Chromatography

    OpenAIRE

    T. K. Laha; S. Sen; G. Mishra

    2015-01-01

    A rapid and sensitive high performance liquid chromatographic method is described for simultaneous determination of duloxetine and its major metabolites, such as 4- hydroxy duloxetine (M7), Glucuronide conjugate of 5-hydroxy-6-methoxy duloxetine (M6) and Glucuronide conjugate of dihydrodiol duloxetine (M12) in rabbit plasma. HPLC analysis was carried out on a µ-Bondapak C18 column (250 mm × 4.6 mm, 5µm particle size) using methanol: phosphate buffer (pH 7.9, 50 mM) (7:3 v/v) as the mobile pha...

  19. Determination of oligofructose, a soluble dietary fiber, by high-temperature capillary gas chromatography.

    Science.gov (United States)

    Joye, D; Hoebregs, H; Joye, D; Hoebregs, H

    2000-01-01

    A high-temperature capillary gas chromatographic method was developed for the quantitative determination of oligofructose in foods and food products. Sample preparation involves oxymation and silylation of the extracted sugars. The oximetrimethylsilyl derivatives are analyzed on an apolar capillary column, with detection by flame ionization. The method is accurate, with recovery of spiked samples at >96%. Repeatability was excellent; RSD values of 1.1% were obtained. Other common oligosaccharides, such as malto-, isomalto-, and galactooligosaccharides, and levan do not interfere, making the method specific and reliable.

  20. Determination of drug stability in aspirin tablet formulations by high-pressure liquid chromatography.

    Science.gov (United States)

    Taguchi, V Y; Cotton, M L; Yates, C H; Millar, J F

    1981-01-01

    Salicylic acid and aspirin were resolved from the other salicylates in thermally degraded multicomponent tablets and determined quantitatively. The analytical method involved wetting the powdered tablet with acetic acid and diluting with chloroform to extract the drug components. Automated high-pressure liquid chromatographic analyses of filtered extracts were performed on a silica column with a mobile phase of acetic acid in heptane. The method was capable of resolving the major thermally induced transformation products in tablet formulations. It was sensitive to approximately 0.1 mg of salicylic acid/tablet. Good agreement with the compendial method for free salicylic acid was obtained.