An Interlaboratory Comparison Study of Supercritical Fluid Extraction for Environmental Samples

An Interlaboratory Comparison Study of Supercritical Fluid Extraction for Environmental Samples PDF Author: Tammy L. Jones
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Languages : en
Pages :

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An Interlaboratory Comparison Study of Supercritical Fluid Extraction for Environmental Samples

An Interlaboratory Comparison Study of Supercritical Fluid Extraction for Environmental Samples PDF Author: Tammy L. Jones
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Analytical Supercritical Fluid Extraction Techniques

Analytical Supercritical Fluid Extraction Techniques PDF Author: E.D. Ramsey
Publisher: Springer Science & Business Media
ISBN: 9401149488
Category : Science
Languages : en
Pages : 449

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Book Description
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.

Supercritical Fluid Extraction of Plant and Environmental Samples

Supercritical Fluid Extraction of Plant and Environmental Samples PDF Author: Wan A. Wan Ibrahim
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Since the inception of analytical supercritical fluid extraction (SFE) in the early 80's, this technique has garnered great attractions in the extractions of variety of analytes from variety of matrices. In this study. supercritical carbon dioxide (SC CO2) has been examined as a sample preparation method for the extraction of eugenol from plant matrix prior to high performance liquid chromatography (HPLC) analysis and for the extraction of organochlorine pesticides (OCPs) from sewerage sludges and chlorpyrifos from formulation and soil samples prior to capillary gas chromatography (GC) analysis. This is an area of considerable interest as many current methods use environmentally hazardous chlorinated solvents and alternative methods are required. Although numerous studies have examined the potential application of SFE to isolate pesticides and plant products, the work has been qualitative rather than quantitative. The present work describes studies which have examined the supercritical conditions needed for complete extraction of the pesticides and plant product eugenol. Initially a complex matrix sludge was chosen. Later a simple matrix soil was chosen and a single pesticide chlorpyrifos was used as the SFE of sludge was unsuccessful. In the extraction of chlorpyrifos problems were encountered in the trapping of the extract on depressurisation of the SC CO2. The effect of collection solvent, CO2 flow rate, solvent depth, and restrictor heating on the trapping efficiency have been investigated. Two methods of trapping were evaluated. Once a quantitative trapping method was established, the effect of different soil matrices on the recovery of chlorpyrifos at different chlorpyrifos spiking level was investigated. The SFE of soil was compared to Soxhlet extraction.

Analytical Supercritical Fluid Extraction

Analytical Supercritical Fluid Extraction PDF Author: Maria D. Luque de Castro
Publisher: Springer Science & Business Media
ISBN: 3642786731
Category : Science
Languages : en
Pages : 332

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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.

Supercritical Fluid Extraction and its Use in Chromatographic Sample Preparation

Supercritical Fluid Extraction and its Use in Chromatographic Sample Preparation PDF Author: S.A. Westwood
Publisher: Springer Science & Business Media
ISBN: 9401121648
Category : Science
Languages : en
Pages : 180

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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.

Analysis with Supercritical Fluids: Extraction and Chromatography

Analysis with Supercritical Fluids: Extraction and Chromatography PDF Author: Bernd Wenclawiak
Publisher: Springer Science & Business Media
ISBN: 3642774741
Category : Science
Languages : en
Pages : 225

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Book Description
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.

Supercritical Fluid Extraction

Supercritical Fluid Extraction PDF Author: Jennifer Maria Wing
Publisher:
ISBN:
Category :
Languages : en
Pages : 362

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Supercritical Fluid Extraction

Supercritical Fluid Extraction PDF Author: Larry T. Taylor
Publisher: Wiley-Interscience
ISBN:
Category : Science
Languages : en
Pages : 208

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Book Description
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.

Evaluation of Various Supercritical Fluid Extraction Systems for Extracting Organics from Environmental Samples

Evaluation of Various Supercritical Fluid Extraction Systems for Extracting Organics from Environmental Samples PDF Author: Viorica Lopez-Avila
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Supercritical Fluid Extraction and Chromatography

Supercritical Fluid Extraction and Chromatography PDF Author: Bonnie A. Charpentier
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 272

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