Download or read book Gas Extraction written by Gerd Brunner and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Application of compressed gases as solvents has found widespread interest within the scientific community. Its processes have industrial applications. Gas Extraction deals with the possibilities of supercritical gases as solvents for separation processes. The volume combines physico-chemical aspects with chemical engineering methods. The text generalizes as far as possible, and treats examples in detail. Gas Extraction covers, for the first time, the subject in textbook form. Most of the examples provide new results that will be helpful for practicing scientists, engineers, and students who want to make use of the techniques.
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 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.
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 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 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 Extraction of Natural Products Using Near Critical Solvents written by M.B. King and published by Springer Science & Business Media. This book was released on 1992-12-31 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to present the current state of the art of extracting natural products with near-critical solvents and to view the possibilities of further extensions of the technique. Relevant background theory is given but does not dominate the book. Carbon dioxide is the near-critical solvent used in most recent applications and inevitably receives prominence. In addition to general descriptions and reviews, the book contains three chapters by indus trial practitioners who describe in detail the operation of their processes and discuss the market for their products. Sections on the design of the pressure vessels and pumps required in these processes and on the acquisition of the data required for design are included. The costing of the processes is also discussed. There is good scope for combining a near-critical extraction step with other process steps in which the properties of near-critical solvents are utilised, for example as a reaction or crystallisation medium and a chapter is devoted to these important aspects. It is hoped that the work will be found to contain a great deal of specific information of use to those already familiar with this field. However the style of presentation and content is such that it will also be useful as an introduction. In particular it will be helpful to those wondering if this form of separation method has anything to offer for them, whether they are engineers, chemists or managers in industry, or in academic or research institutions.
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 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 Natural Bioactive Compounds written by Rajeshwar P. Sinha and published by Academic Press. This book was released on 2020-10-06 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural Bioactive Compounds: Technological Advancements deals with the latest breakthroughs in the field of screening, characterization and novel applications of natural bioactive compounds from diverse group of organisms ranging from bacteria, viruses, cyanobacteria, algae, fungi, bryophytes, higher plants, sponges, corals and fishes. Written by some of the most reputed scientists in the field, this book introduces the reader to strategies and methods in the search for bioactive natural products. It is an essential read for researchers and students interested in bioactive natural products, their biological and pharmacological properties, their possible use as chemopreventive or chemotherapeutic agents, and other future potential applications. - Explores natural sources of bioactive compounds, including cyanobacteria, bacteria, viruses, fungi and higher plants - Discusses the potential applications of biological products, such as their use in medicine (antibiotics, cancer research, immunology), as food additives, supplements and technological substances - Analyzes the contributions of emerging or developing technologies for the study of bioactive natural compounds (characterization and purification)
Download or read book Solubility in Supercritical Carbon Dioxide written by Ram B. Gupta and published by CRC Press. This book was released on 2006-12-06 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supercritical fluid extraction is an environmentally safe and cost-effective alternative to traditional organic solvents. Carbon dioxide is widely used as the solvent of choice for applications such as caffeine and nicotine extraction due to its mild critical temperature, nontoxicity, nonflammability, and low cost. Introducing the most complete col
Download or read book Green Extraction of Natural Products written by Farid Chemat and published by John Wiley & Sons. This book was released on 2016-03-11 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extraction processes are essential steps in numerous industrial applications from perfume over pharmaceutical to fine chemical industry. Nowadays, there are three key aspects in industrial extraction processes: economy and quality, as well as environmental considerations. This book presents a complete picture of current knowledge on green extraction in terms of innovative processes, original methods, alternative solvents and safe products, and provides the necessary theoretical background as well as industrial application examples and environmental impacts. Each chapter is written by experts in the field and the strong focus on green chemistry throughout the book makes this book a unique reference source. This book is intended to be a first step towards a future cooperation in a new extraction of natural products, built to improve both fundamental and green parameters of the techniques and to increase the amount of extracts obtained from renewable resources with a minimum consumption of energy and solvents, and the maximum safety for operators and the environment.
Download or read book New Generation Green Solvents for Separation and Preconcentration of Organic and Inorganic Species written by Mustafa Soylak and published by Elsevier. This book was released on 2020-04-07 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: New Generation Green Solvents for Separation and Preconcentration of Organic and Inorganic Species is designed to help researchers and students understand the production and application of new generation green solvents in separation- and preconcentration-based analytical methods. Beginning with the historical background and milestones in the development of analytical instrumentation, the book goes on to give a detailed overview of the most up-to-date uses of green solvents in sample preparation. Using a wealth of examples, it compares old and new extraction procedures and explores the many applications of new generation green solvents. Practical, easy-to-follow experiments are used to illustrate the key concepts. This practical guide helps to promote the use of safer, more sustainable solvents in analytical chemistry and beyond for environmental scientists, researchers in pharmaceutical and biotech industries, and students in analytical chemistry. - Covers the basic analytical theory essential for understanding extraction- and microextraction-based separation and preconcentration methods - Explains combination use of new generation solvents with various detection systems, including UV-VIS, ICP-MS, HPLC, LC-MS, GC-MS, and LC-MS/MS - Emphasizes trace chemical component separation, preconcentration and 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 Trace Determination of Pesticides and their Degradation Products in Water BOOK REPRINT written by Damia Barcelo and published by Elsevier. This book was released on 1997-12-15 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trace Determination of Pesticides and their Degradation Products in Water is a critical compilation of analytical methods for the monitoring of pesticides and their degradation products in water. It contains up-to-date material and is the result of the authors' experience in the pesticide analysis field. The book is structured in six chapters, starting from general aspects of pesticides like usage, physicochemical parameters and occurrence in the environment. A second chapter is devoted to sampling from water matrices, stability methods of pesticides in water and quality assurance issues. The general chromatographic methods for pesticides are reported, including the newly developed electrophoresis methods and GC-MS and LC-MS confirmatory analytical methods. Sample preparation methodologies, including off-line and on-line techniques are described in the next two chapters, with a comprehensive list of examples of pesticides and many metabolites, including the use of different GC-methods and LC-methods. The final chapter is devoted to the development of biological techniques, immunoassays and biosensors, for the trace determination of pesticides in water samples.
Download or read book Recent Advances in Natural Products Analysis written by Seyed Mohammad Nabavi and published by Elsevier. This book was released on 2020-03-07 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent Advances in Natural Products Analysis is a thorough guide to the latest analytical methods used for identifying and studying bioactive phytochemicals and other natural products. Chemical compounds, such as flavonoids, alkaloids, carotenoids and saponins are examined, highlighting the many techniques for studying their properties. Each chapter is devoted to a compound category, beginning with the underlying chemical properties of the main components followed by techniques of extraction, purification and fractionation, and then techniques of identification and quantification. Biological activities, possible interactions, levels found in plants, the effects of processing, and current and potential industrial applications are also included. - Focuses on the latest analytical techniques used for studying phytochemical and other biological compounds - Authored and edited by the top worldwide experts in their field - Discusses the current and potential applications and predicts future trends of each compound group
Download or read book Essentials of Botanical Extraction written by Subhash C. Mandal and published by Academic Press. This book was released on 2015-02-02 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essentials of Botanical Extraction: Principles and Applications provides a unique, single source of valuable information on the various botanical extraction methods available, from conventional to the use of green and modern extraction technologies including ultrasounds, microwaves, pressurized liquids, and supercritical fluids. Most extracts obtained from botanicals are often poorly characterized with unidentified active or inactive constituents. A wise selection of an extraction strategy is vital to drug discovery from medicinal plants as extraction forms the basic first step in medicinal plant research. This book also explores the mathematical hypotheses and innovations in botanical extractions and analyzes different post extraction operations so that dependency on serendipity is reduced and the same be converted into programmed drug discovery. - Reviews the history and current state of natural product drug discovery and development, highlighting successes and current issues - Explains the application of chemometric tools in extraction process design and method development - Introduces process intensification as applied to the processing of medicinal plant extracts for rapid and cost-effective extraction
