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 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 Supercritical Fluid Extraction and Its Use in Chromatographic Sample Preparation written by S. A. Westwood and published by Chapman & Hall. This book was released on 1993-01-01 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 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 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 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 Practical Supercritical Fluid Chromatography and Extraction written by Thomas Caudell and published by Routledge. This book was released on 2018-05-08 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: An exploration of fundamental as well as practical aspects of supercritical fluid chromatography and extraction. It addresses topics such as: packed columns in SFC; detection in SFC; supercritical fluid chromatography/mass spectroscopy; and evaporative light scattering detection in SFC.

Download or read book Modern Sample Preparation for Chromatography written by Serban C. Moldoveanu and published by Elsevier. This book was released on 2021-02-24 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern Sample Preparation for Chromatography, Second Edition explains the principles of sample preparation for chromatographic analysis. A variety of procedures are applied to make real-world samples amenable for chromatographic analysis and to improve results. This book's authors discuss each procedure's advantages, disadvantages and their applicability to different types of samples, along with their fit for different types of chromatographic analysis. The book contains numerous literature references and examples of sample preparation for different matrices and new sections on green approaches in sample preparation, progress in automation of sample preparation, non-conventional solvents for LLE (ionic liquids, deep eutectic mixtures, and others), and more. - Presents numerous techniques applied for sample preparation for chromatographic analysis - Provides an up-to-date source of information regarding the progress made in sample preparation for chromatography - Describes examples for specific types of matrices, providing a guide for choosing the appropriate sample preparation method for a given analysis

Download or read book Supercritical Fluid Chromatography written by Colin F. Poole and published by Elsevier. This book was released on 2017-02-16 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluid chromatography (SFC) is a rapidly developing laboratory technique for the separation and identification of compounds in mixtures. Significant improvements in instrumentation have rekindled interest in SFC in recent years and enhanced its standing in the scientific community. Many scientists are familiar with column liquid chromatography and its strengths and weaknesses, but the possibilities brought to the table by SFC are less well-known and are underappreciated. Supercritical Fluid Chromatography is a thorough and encompassing reference that defines the concept of contemporary practice in SFC and how it should be implemented in laboratory science. Given the changes that have taken place in SFC, this book presents contemporary aspects and applications of the technique and introduces SFC as a natural solution in the larger field of separation science. The focus on state-of-the-art instrumental SFC distinguishes this work as the go-to reference work for those interested in implementing the technique at an advanced level. - Edited and authored by world-leading chromatography experts - Provides comprehensive coverage of SFC in a single source - Extensive referencing facilitates identification of key research developments - More than 200 figures and tables aid in the retention of key concepts

Download or read book Hyphenated Techniques in Supercritical Fluid Chromatography and Extraction written by K. Jinno and published by Elsevier. This book was released on 1992-07-21 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book to focus on the latest developments in hyphenated techniques using supercritical fluids. The advantages of SFC in hyphenation with various detection modes, such as FTIR, MS, MPD and ICP and others are clearly featured throughout the book. Special attention is paid to coupling of SFE with GC or SFC.In this edited volume, chapters are written by leading experts in the field. The book will be of interest to professionals in academia, as well as to those researchers working in an industrial environment, such as analytical instrumentation, pharmaceuticals, agriculture, food, petrochemicals and environmental.

Download or read book Systematic Approach to On line Supercritical Fluid Extraction Supercritical Fluid Chromatography Tandem Mass Spectrometry Method Development written by Alison Paige Wicker and published by . This book was released on 2020 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coupling supercritical fluid extraction (SFE) on-line with supercritical fluid chromatography (SFC) - tandem mass spectrometry (MS/MS) provides a platform for extraction, separation, and detection in a single analysis. Utilization of this technique simplifies sample preparation while limiting sample loss and/or contamination and significantly decreases total analysis time. SFE-SFC-MS/MS requires consideration of many extraction and chromatographic variables to not only provide the most efficient extraction, but to analytically transfer the extracted analytes to the column for separation. There is a fundamental lack of understanding of how the variables in SFE affect those in SFC. In the first study, on-line SFE-SFC-MS/MS was applied for the determination of polycyclic aromatic hydrocarbons (PAHs) in soil. The purpose of this study was to develop and validate the first on-line SFE-SFC-MS/MS method for the quantification of PAHs in various types of soil. Parameters for on-line extraction coupled to chromatographic analysis were optimized. The method was validated for concentrations of 10-1500 ng of PAHs per gram of soil in Certified Reference Material (CRM) sediment, clay, and sand with R2≥0.99. Limits of detection (LOD) were found in the range of 0.001-5 ng/g, and limits of quantification (LOQ) in the range of 5-15 ng/g. The method developed in this study can be effectively applied to the study of PAHs in the environment, and lays the foundation for further applications of on-line SFE-SFC-MS. Typically, a univariate approach is taken in on-line SFE-SFC-MS/MS method development which provides little insight into how the variables work together. In the second study, a multivariate approach was used to develop a better understanding of the synergistic relationship between the extraction and separation processes by focusing on the optimization of extraction parameters for target analytes with a wide range of physicochemical properties in matrices of variable retentivity. Optimal extraction parameters were determined for 18 analytes in three variable sample types. Compromise in optimal extraction parameters must be made when simultaneously extracting and analyzing a significantly wide range of analytes. Detection of drugs of abuse (DoA) in hair; being a convenient and noninvasive technique for the determination of controlled substances, is important in forensics and toxicology. SFE-SFC-MS/MS being ideal for DoA determination in complex matrices, provides a highly specific and sensitive chemical analysis while limiting the need for extensive manual sample preparation. Supercritical fluid extraction of seventeen DoAs from human hair was performed on-line using carbon dioxide (CO2) with 5 mM ammonium formate in methanol. Optimal conditions for simultaneously extracting 17 drugs of abuse were predicted using models developed by response surface methodology. Multivariate analysis was used to optimize extraction parameters, including time (static and dynamic), modifier concentration, flow rate and extraction pressure. It was determined that a compromise between flow rate and concentration was required. Optimal extraction occurred using 15% modifier at 5.00 mL/min for an 8 minute static extraction followed by 15 minutes of dynamic flow at 2 % modifier with a 30 °C extraction vessel temperature and dual backpressures of 10.0 MPa. Significant performance differences were observed between the extraction of standard analytes spiked onto blank hair samples and extraction of a known drug user's hair where the analytes of interest were incorporated into hair growth. The known drug user's hair required multiple extractions to liberate the illicit substance from the complex hair matrix. The amount of analyte extracted during a third round of extractions was observed at double the amount extracted in the first extraction. In samples with spiked on analytes, the amount of extracted analyte decreased with each consecutive extraction. More work is needed to address the matrix effects of drugs incorporated into hair. Most methods developed for hair analysis rely upon spiked samples; however, it appears that a spiked sample versus an incorporated sample may not be comparable. Determining a better method for incorporating standards into hair will provide the basis for an improved extraction and quantification.

Download or read book Practical Supercritical Fluid Chromatography and Extraction written by Thomas Caudell and published by CRC Press. This book was released on 1999-03-08 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the fundamental and practical aspects of supercritical fluid chromatography (SFC) and extraction. It discusses packed columns in SFC; detection in SFC; supercritical fluid chromatography/mass spectroscopy; and evaporative light scattering detection in SFC.

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 Practical Application of Supercritical Fluid Chromatography for Pharmaceutical Research and Development written by and published by Elsevier. This book was released on 2022-12-02 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical Application of Supercritical Fluid Chromatography for Pharmaceutical Research and Development provides a valuable "go-to reference for many difficult-to-solve challenges using pertinent chromatographic theory, first-hand case studies, and examples provided from academic and industry experts. This text also enables professors teaching an analytical instrumental course to introduce and instruct students about one of the most sustainable and powerful separation methods currently available. While the text has broad applicability across industrial sectors, it focuses primarily on application in the pharmaceutical industry. The book is designed to allow readers to align current HPLC/UHPLC capabilities with SFC as an orthogonal tool for project specific methods in the pharmaceutical industry. It highlights where SFC falls on the spectrum of useful chromatographic tools for routine and challenging separative methods. Experienced HPLC users who are interested in developing knowledge in orthogonal separation techniques, as well as newcomers to the field of separation science, will find this text particularly useful. Chapters address where SFC may fit the analytical needs of the pharmaceutical industry and alert the readers as to where the technique will not fit. Readers will gain an understanding of how and where SFC may be applied and adapted more routinely across the pharmaceutical industry as a 'green' way of undertaking separation opportunities and challenges. Areas within the pharmaceutical industry include early drug discovery, process chemistry, and late stage development and manufacturing. - Describes approaches to SFC column and mobile phase selection for method development for both analytical and preparative tasks - Gives practical examples of how analytical SFC enables the monitoring of synthetic reactions including unstable intermediates, chiral and achiral polar reactants and products across small and large modalities - Provides need-focused case studies for pharmaceutical analysts, process chemists, and contract chemistry facilities that can benefit from monitoring or purifying polar intermediates, mutagenic impurities, nitrosamines and other reaction by-products including excipients and metabolites

Download or read book Supercritical Fluid Extraction written by Mark McHugh and published by Elsevier. This book was released on 2013-10-22 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical Fluid Extraction is a technique in which CO2 is used under extremely high pressure to separate solution (e.g., removing caffeine from coffee). Separations is basic to all process industries and supercritical fluid extraction is a specific type which is receiving a high level of attention. The book will combine basic fundamentals with industrial applications. The second edition has been expanded and updated and includes new chapters on chromatography and food processing. "...this is an excellent book which is both instructive and amusing to read. Its true value is neatly summarised in one of the closing sentences: 'We have supplied you with the guidelines and criteria which you can now apply when considering supercritical fluids for your own needs.'' - Chemistry in Britain, February 1995