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Powerful Analytical Tool (powerful + analytical_tool)
Selected AbstractsProbing interactions by means of pulsed field gradient nuclear magnetic resonance spectroscopy,MAGNETIC RESONANCE IN CHEMISTRY, Issue S1 2008Sara Cozzolino Abstract Molecular self-diffusion coefficients (D) of species in solution are related to size and shape and can be used for studying association phenomena. Pulsed field gradient nuclear magnetic resonance (PFG-NMR) spectroscopy has been revealed to be a powerful analytical tool for D measurement in different research fields. The present work briefly illustrates the use of PFG-NMR for assessing the existence of interactions in very different chemical systems: organic and organometallic compounds, colloidal materials and biological aggregates. The application of PFG-NMR is remarkable for understanding the role of anions in homogenous transition metal catalysis and for assessing the aggregation behaviour of biopolymers in material science. Copyright © 2008 John Wiley & Sons, Ltd. [source] Analytical investigation of styrax and benzoin balsams by HPLC- PAD-fluorimetry and GC-MSPHYTOCHEMICAL ANALYSIS, Issue 4 2008Michael Hovaneissian Abstract An HPLC and GC study has been conducted on the aromatic oleoresins styrax and benzoin produced by several American, Mediterranean and East-Asian trees, and widely used in ancient civilisations for their therapeutic and odoriferous properties. Initial experiments were performed by HPLC-PAD-fluorimetry for the analysis of several aromatic components, and then completed by GC-MS for the characterisation of both aromatic and triterpenic derivatives. In this work, it was crucial to isolate from fresh natural exudates, and to characterise by two-dimensional NMR, some of the major constituents in order to extend the standard molecular pool prior to chromatographic identifications. This study reveals coniferyl benzoate as an excellent distinctive fluorescent biomarker of Siam benzoin substrate. It also confirms that fluorimetric-coupled detection is a powerful analytical tool for the identification of compounds in Hamamelidaceae extracts that are almost undetectable by UV. GC-MS was successfully applied to the determination of the botanical origin of Sumatra benzoin, and to the identification of lupeol [3, -lup-20(29)-en-3-ol] for the first time in such balsam-type materials. Copyright © 2007 John Wiley & Sons, Ltd. [source] Communication with the Environment?POLITICS, Issue 3 2000Non-human Nature in the Theories of Jürgen Habermas The theories of Jürgen Habermas provide us with a powerful analytical tool for the analysis of politics, including social movements. However, they are lacking in one particular area, the analysis of environmental politics. The reasons behind these difficulties can be traced through the development of Habermas's work and lie in the inability of non-human nature to participate in language-based discourse. The dilemma is acute , the ecocentric moral position needs grounding in the rationality of discourse if it is not to slip into possibly dangerous irrationality, but how can such a grounding occur? This article reviews the development of discussion in this area and investigates advocacy as a possible resolution of the problem. [source] A reliable analytical approach based on gas chromatography coupled to triple quadrupole and time-of-flight mass analyzers for the determination and confirmation of polycyclic aromatic hydrocarbons in complex matrices from aquaculture activitiesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 13 2009Jaime Nácher-Mestre The potential of gas chromatography coupled to tandem mass spectrometry (GC/MS/MS) with a triple quadrupole analyzer (QqQ) has been investigated for the quantification and reliable identification of sixteen polycyclic aromatic hydrocarbons (PAHs) from the EPA priority list in animal and vegetable samples from aquaculture activities, whose fat content ranged from 5 to 100%. Matrices analyzed included fish fillet, fish feed, fish oil and linseed oil. Combining optimized saponification and solid-phase extraction led to high efficiency in the elimination of interfering compounds, mainly fat, from the extracts. The developed procedure minimized the presence of these interfering compounds in the extracts and provided satisfactory recoveries of PAHs. The excellent sensitivity and selectivity of GC/(QqQ)MS/MS in selected reaction monitoring (SRM) allowed to reach limits of detection at pg/g levels. Two SRM transitions were acquired for each analyte to ensure reliable identification of compounds detected in samples. Confirmation of positive findings was performed by GC coupled to high-resolution time-of-flight mass spectrometry (GC/TOFMS). The accurate mass information provided by GC/TOFMS in full acquisition mode together with its high mass resolution makes it a powerful analytical tool for the unequivocal confirmation of PAHs in the matrices tested. The method developed was applied to the analysis of real-world samples of each matrix studied with the result of detecting and confirming the majority of analytes at the µg/kg level by both QqQ and TOF mass spectrometers. Copyright © 2009 John Wiley & Sons, Ltd. [source] Product ion mass spectra of amphetamine-type substances, designer analogues, and ketamine using ultra-performance liquid chromatography/tandem mass spectrometry,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 15 2006Luigino G. Apollonio This paper describes the application of ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) technology to separate and identify amphetamine-type substances (amphetamine, methamphetamine), common and novel designer analogues (MDA, MDMA, PMA, 4-MTA, MBDB), and ketamine using Acquity UPLC/Micromass Quattro Micro API mass spectrometer instrumentation (Waters Corporation, USA). From injection of drug reference standards, it was demonstrated that these compounds can be identified by product ion mass spectra in less than 4,min total analysis time, indicating that the technological advancements associated with UPLC/MS/MS allow it to serve as a powerful analytical tool for high-throughput testing. In addition to demonstrating the separation and response of these drug compounds under the stated UPLC/MS/MS conditions, we believe the acquired product ion spectra will be a beneficial reference to laboratories interested in incorporating the use of this technology in the routine analysis of drugs of abuse. Copyright © 2006 John Wiley & Sons, Ltd. [source] The evolution of comprehensive two-dimensional gas chromatography (GC×GC)JOURNAL OF SEPARATION SCIENCE, JSS, Issue 5-6 2004Tadeusz Górecki Abstract For a technology little over a decade old, comprehensive two-dimensional gas chromatography (GC×GC) has quickly reached the status of one of the most powerful analytical tools for volatile organic compounds. At the heart of any GC×GC system is an interface, which physically connects the primary and the secondary columns and acts to preserve the separation obtained in the first dimension (first column) while allowing additional separation in the second dimension. The paper presents a review of the technology, including fundamental principles of the technique, data processing and interpretation and a timeline of inventive contributions to interface design. In addition, applications of the technique are presented, with a more detailed discussion of selected examples. [source] Recent innovations in marine biologyMARINE ECOLOGY, Issue 2009Ferdinando Boero Abstract Modern ecology arose from natural history when Vito Volterra analysed Umberto D'Ancona's time series of Adriatic fisheries, formulating the famous equations describing the linked fluctuations of a predator,prey system. The shift from simple observation to careful sampling design, and hypothesis building and testing, often with manipulative approaches, is probably the most relevant innovation in ecology, leading from descriptive to experimental studies, with the use of powerful analytical tools to extract data (from satellites to molecular analyses) and to treat them, and modelling efforts leading to predictions. However, the historical component, time, is paramount in environmental systems: short-term experiments must cope with the long term if we want to understand change. Chaos theory showed that complex systems are inherently unpredictable: equational, predictive science is only feasible over the short term and for a small number of variables. Ecology is characterized by a high number of variables (e.g. species) interacting over wide temporal and spatial scales. The greatest recent conceptual innovation, thus, is to have realized that natural history is important, and that the understanding of complexity calls for humility. This is not a return to the past, because now we can give proper value to statistical approaches aimed at formalizing the description and the understanding of the natural world in a rigorous way. Predictions can only be weak, linked to the identification of the attractors of chaotic systems, and are aimed more at depicting scenarios than at forecasting the future with precision. Ecology was originally split into two branches: autecology (ecology of species) and synecology (ecology of species assemblages, communities, ecosystems). The two approaches are almost synonymous with the two fashionable concepts of today: ,biodiversity' and ,ecosystem functioning'. A great challenge is to put the two together and work at multiple temporal and spatial scales. This requires the identification of all variables (i.e. species and their ecology: biodiversity, or autoecology) and of all connections among them and with the physical world (i.e. ecosystem functioning, or synecology). Marine ecosystems are the least impacted by human pressures, compared to terrestrial ones, and are thus the best arena to understand the structure and function of the natural world, allowing for comparison between areas with and areas without human impact. [source] | ||||||||||