Download or read book Analytical Supercritical Fluid Extraction written by Maria D. Luque de Castro and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in analytical chemistry have turned it into a virtually unrecognizable science compared to a few decades ago, when it lagged behind other sciences and techniques. However, advances in analytical science have been far from universal: while innovations in instrumentation and data acquisition and processing systems have reached unprecedented levels thanks to parallel breakthroughs in computer science and chemo metrics, progress in preliminary operations has been much slower despite their importance to analytical results. Thus, such clear trends in analytical process development as automation and miniaturization have not reached preliminary operations to the same extent, even though this area is pro bably in the greatest need. Improvement in preliminary operations is thus an urgent goal of analytical chemistry on the verge of the twenty first century. Increased R&D endeavours and manufacture of commercially available automatic equipment for implementation of the wide variety of operations that separate the uncollected, unmeasured, untreated sample from the signal measuring step are thus crucial on account of the wide variability of such operations, which precludes development of all-purpose equipment, and the complexity of some, particularly relating to solid samples. Supercritical fluid extraction opens up interesting prospects in this context and is no doubt an effective approach to automatioI1 and mini aturization in the preliminary steps of the analytical process. The dramatic developments achieved in its short life are atypical in many respects.
Download or read book Analysis with Supercritical Fluids Extraction and Chromatography written by Bernd Wenclawiak and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of supercritical fluids in analytical chemistry is still grow ing. More and more analysts are discovering the favorable advan tages for a number of applications. Especially supercritical fluid extraction (SFE) has attracted a lot of interest in recent years due to its simplicity. Supercritical fluid chromatography (SFC) has become better established and the development of this technique has been accelerated by the many applications with capillary col umns which have been published in the literature. At first SFC equipment was based on instruments commonly used for liquid chromatography, and the first commercial in struments were derived from this technology. However, capillary columns can be much more easily interfaced to gas chromatogra phy equipment especially to the detectors commonly used for Oc. Many stationary phases both for packed micro columns and capillary columns have been designed for SFC purposes extending this technology to LC and OC. The most common fluid applied in SFC and SFE is carbon dioxide. The advantages of supercritical CO , such as having dif 2 fusivity like a gas and solvating power depending on temperature and pressure, are also valid for other fluids and modified fluids. Both properties are valuable for sample extraction and extraction selectivity.
Download or read book Analytical Supercritical Fluid Extraction Techniques written by E.D. Ramsey and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past decade supercritical fluid extration (SFE) has attracted considerable attention as a sample preparation procedure in analytical chemistry. The successful implementation of this technique can lead to improved sample throughput, more efficient recovery of analytes, cleaner extracts, economic replacement of halogenated solvents and a high level of automation, compared to conventional sample preparation procedures. This book provides an overview of basic principles of SFE as well as in-depth reviews of both on- and off-line SFE methods. The on-line coupling of SFE with both chromatographic and spectroscopics techniques has been the subject of a great deal of research effort and is dealt with in detail. Newer developments, such as off-line SFE of solid and liquid matrices, are starting to attract a great deal of interest, and the coverage of these areas will prove of particular value to the analytical chemist. The international team of authors has illustrated these topics with many `state-of-the-art' applications, and each chapter provides a comprehensive list of references. For the convenience of the reader, an appendix which contains pressure conversion scales and supercritical fluid carbon dioxide density tables appears at the end of the book. The volume's extensive coverage of both on-line and off-line extraction will be particularly useful to analytical chemists, in a wide range of environments, seeking to develop high quality, simple and robust SFE methods.
Download or read book Applications of Supercritical Fluids in Industrial Analysis written by J.R. Dean and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: The continued search for rapid, efficient and cost-effective means of analytical measurement has introduced supercritical fluids into the field of analytical chemistry. Two areas are common: supercritical fluid chroma tography and supercritical fluid extraction. Both seek to exploit the unique properties of a gas at temperatures and pressures above the critical point. The most common supercritical fluid is carbon dioxide, employed because of its low critical temperature (31 °C), inertness, purity, non-toxicity and cheapness. Alternative supercritical fluids are also used and often in conjunction with modifiers. The combined gas-like mass transfer and liquid-like solvating characteristics have been used for improved chroma tographic separation and faster sample preparation. Supercritical fluid chromatography (SFC) is complementary to gas chro matography ( GC) and high performance liquid chromatography (HPLC), providing higher efficiency than HPLC, together with the ability to analyse thermally labile and high molecular weight analytes. Both packed and open tubular columns can be employed, providing the capability to analyse a wide range of sample types. In addition, flame ionization detection can be used, thus providing 'universal' detection.
Download or read book Introduction to Supercritical Fluid Extraction written by Larry T. Taylor and published by . This book was released on 1995 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supercritical Fluid Extraction and its Use in Chromatographic Sample Preparation written by S.A. Westwood and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: by Professor D. E. Games, Mass Spectrometry Research Unit, University College of Swansea Sample preparation can be viewed as occupying a Cinderella role in analytical science. However, the quality of sample preparation plays a key role in high In the past decade, there has been quality analysis and deserves higher stature. considerable interest in the use of supercritical fluid extraction (SFE) as an alternative to conventional procedures for the preparation of samples for ana lysis. The driving force for this development is the need for automated, sim pler, faster, non-destructive and selective methods for extraction, preferably using non-toxic extraction media which are easily disposed of. Utilization of supercritical fluids for extraction fulfils these requirements because of their unique physical chemical properties and usually low toxicity. Selectivity can be achieved by suitable selection of pressure (density), temperature and modi fier conditions which enable solvating power to be varied. The high diffusivity of supercritical fluids provides rapid sample penetration and extraction. Use of fluids with low critical temperatures enables extraction to be conducted under mild thermal conditions ensuring that thermally labile compounds do not decompose. The technique can be used off-line, and the extracts analysed by appropriate techniques, or it can be used on-line, by coupling with a variety of chromatographic techniques. These can then, if necessary, be coupled fur ther with spectroscopic techniques, such as Fourier transform infrared, ultra violet or mass spectrometry, to provide specific identification or structural information.
Download or read book Analysis with Supercritical Fluids written by Bernd Wenclawiak and published by . This book was released on 1992-11-03 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The editor has brought together in a compact and readable form the new methods of analytical chemistry using supercritical fluids. The volume provides comprehensive treatment of supercritical fluid chromatography (SFC) and supercritical fluid extraction (SFE); it discusses both theory and practice. The contributions are written by leading experts in their fields with exhaustive practical experience in SFC and SFE. Special attention is given to the description of applications and thus provides the experienced analyst with invaluable information widely scattered in the literature and helps the novice to adopt these new techniques quickly in his laboratory. An addendum includes brand new literature on SFC and SFE.
Download or read book Analytical Supercritical Fluid Extraction of Lipid Containing Samples written by Mattias Järemo and published by . This book was released on 1998 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supercritical Fluid Technology in Oil and Lipid Chemistry written by Jerry W. King and published by The American Oil Chemists Society. This book was released on 1996 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermodynamics of supercritical fluids with respect to lipid-containing systems; Solubility measurement of lipid constituents in supercritical fluids; Supercritical fluid extraction of oilseeds/lipids in natural products; Supercritical fractionation of lipids; Oilseed solubility and extraction modeling; Modeling of the supercritical fluid extraction rate of oilseeds; Design and economic analysis of supercritical fluid extraction processes; Supercritical fluid extraction and fractionation of fish oils; Supercritical fluid extraction of egg lipids; Supercritical fluid extraction of Cocoa and Cocoa products; Superctitical CO2 extraction of meat products and edible animal fats for cholesterol reduction; Supercritical fluid extraction of algae; Effect of supercritical fluids on residual meals and protein functionality; Treatment of food materials with supercritical carbon dioxide; Enzymatic synthesis in supercritical fluids; Basic principles and the role of supercritical fluid chromatography in lipid analysis; Supercritical fluid chromatography for the analysis of oleochemicals; Supercritical fluid chromatography of trace components in oils and fats; Analytical supercritical fluid extraction for oil and lipid analysis.
Download or read book Supercritical Fluid Extraction of Nutraceuticals and Bioactive Compounds written by Jose L. Martinez and published by CRC Press. This book was released on 2007-11-28 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enhanced concern for the quality and safety of food products, increased preference for natural products, and stricter regulations on the residual level of solvents, all contribute to the growing use of supercritical fluid technology as a primary alternative for the extraction, fractionation, and isolation of active ingredients. As a solvent-free p
Download or read book Supercritical Fluid Extraction written by Larry T. Taylor and published by Wiley-Interscience. This book was released on 1996-03-13 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: By encouraging a deliberate, systematic approach to supercritical fluid extraction (SFE) methods and techniques, this book enables scientists and technicians to avoid disappointing results and erroneous conclusions and develop reliable guidelines for using this versatile technology.
Download or read book Supercritical Fluids in Chromatography and Extraction written by R. M. Smith and published by Elsevier Science Limited. This book was released on 1997 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the mid 1980s supercritical fluid chromatography (SFC) arose with considerable fanfare as the new technique which would shortly "displace HPLC" and become the "universal separation method". After the initial hype had passed, there has still remained a significant group of applications in both chromatography and extraction for which supercritical fluids are the most suitable solvents. These form the basis of this volume, which illustrates the present state of analytical supercritical technology by a collection of review and research papers. Many publications in this field have blurred the boundaries of supercritical fluids, claiming that they filled a gap between gases and liquids and "had the properties of both". This was never true and this book seeks a more rational view of the state of application of supercritical fluids as their position in the analytical laboratory becomes clearer. These papers emphasise that future chromatographers should not be compartmentalised into "gas chromatographers" or "liquid chromatographers" but should view the field as a series of merging separation techniques. The overall emphasis is on extraction methods, usually as a sample preparation method prior to HPLC or GC analysis, but in some cases the extract is examined directly as the analytical step. This bias on extraction methods reflects the impact of supercritical fluids in the working laboratory. It is therefore an area where advances can have the maximum benefit for the user. The papers on chromatography are diverse and adventurous, covering particularly chiral chromatography and metal complex analysis, where SFC offers particular advantages over existing methods. Rather than be a separate branch of chromatography or extractions it is clear that the use of solvents above their normal conditions of temperature and pressure, up to and including the supercritical state, will continue to expand the range of analytical methods as part of an overall spectrum of solubility, polarity and volatility properties of solvents and mobile phases. This volume is an important addition to this movement and will help to redress the lack of education in the theory and practice of sample preparation which has been a great limiting factor for SFC and SFE.
Download or read book Supercritical Fluids written by E. Kiran and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluids are neither gas nor liquid, but can be compressed gradually from low to high density and they are therefore interesting and important as tunable solvents and reaction media in the chemical process industry. By adjusting the density the properties of these fluids can be customised and manipulated for a given process - physical or chemical transformation. Separation and processing using supercritical solvents such as CO2 are currently on-line commercially in the food, essential oils and polymer industries. Many agencies and industries are considering the use of supercritical water for waste remediation. Supercritical fluid chromatography represents another, major analytical application. Significant advances have recently been made in materials processing, ranging from particle formation to the creation of porous materials. The chapters in this book provide tutorial accounts of topical areas centred around: (1) phase equilibria, thermodynamics and equations of state; (2) critical behaviour, crossover effects; (3) transport and interfacial properties; (4) molecular modelling, computer simulation; (5) reactions, spectroscopy; (6) phase separation kinetics; (7) extractions; (8) applications to polymers, pharmaceuticals, natural materials and chromatography; (9) process scale-up.
Download or read book Oil Extraction and Analysis written by D. L. Luthria and published by CRC Press. This book was released on 2019-06-07 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains papers from the symposium "Critical Issues, Current and Emerging Technologies for Determination of Crude Fat Content in Food, Feed and Seeds," held in 2003 at the AOCS Annual Meeting in Kansas City, Missouri. The topics covered give a broad perspective of the challenges and issues of the value-added enhanced products. This book w
Download or read book Analytical Supercritical Fluid Chromatography and Extraction written by Milton L. Lee and published by Milton Lee. This book was released on 1990 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The 3rd European Symposium on Analytical Supercritical Fluid Chromatography and Extraction written by and published by . This book was released on 1995 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sample Preparation in Chromatography written by S.C. Moldoveanu and published by Elsevier. This book was released on 2002-05-08 with total page 949 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sample preparation is an essential step in many analyses. This book approaches the topic of sample preparation in chromatography in a methodical way, viewing it as a logical connection between sample collection and analytical chromatography. Providing a guide for choosing the appropriate sample preparation for a given analysis, this book describes various ways to process the sample, explaining the principle, discussing the advantages and disadvantages, describing the applicability to different types of samples, and showing the fitness to specific chromatographic determinations. The first part of the book contains an overview of sample preparation showing its relation to sample collection and to the core chromatographic analysis. The second part covers procedures that do not use chemical modifications of the analyte and includes methods for sample dissolution, concentration and cleanup designed mainly for modifying the initial matrix of the sample. This part starts with conventional separations such as filtration and distillation and finishes with more advanced techniques such as solid phase extraction and electroseparations. The third part gives a description of the chemical modifications that can be performed on a sample either for fractionation purposes or to improve a specific property of the analyte. This part includes derivatizations, polymer chemical degradations, and pyrolysis.