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 :

Get Book Here

Book Description
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.

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 :

Get Book Here

Book Description
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.

Supercritical Fluid Extraction

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

Get Book Here

Book Description


Natural Bioactive Compounds

Natural Bioactive Compounds PDF Author: Rajeshwar P. Sinha
Publisher: Academic Press
ISBN: 0128206594
Category : Science
Languages : en
Pages : 504

Get Book Here

Book Description
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)

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

Get Book Here

Book Description
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.

Laboratory Evaluation of Critical Fluid Extractions for Environmental Applications

Laboratory Evaluation of Critical Fluid Extractions for Environmental Applications PDF Author: R. P. DeFilippi
Publisher:
ISBN:
Category : Factory and trade waste
Languages : en
Pages : 102

Get Book Here

Book Description


Supercritical Fluid Technology for Energy and Environmental Applications

Supercritical Fluid Technology for Energy and Environmental Applications PDF Author: Vladimir Anikeev
Publisher: Newnes
ISBN: 0444626972
Category : Technology & Engineering
Languages : en
Pages : 285

Get Book Here

Book Description
Supercritical Fluid Technology for Energy and Environmental Applications covers the fundamental principles involved in the preparation and characterization of supercritical fluids (SCFs) used in the energy production and other environmental applications. Energy production from diversified resources — including renewable materials — using clean processes can be accomplished using technologies like SCFs. This book is focused on critical issues scientists and engineers face in applying SCFs to energy production and environmental protection, the innovative solutions they have found, and the challenges they need to overcome. The book also covers the basics of sub- and supercritical fluids, like the thermodynamics of phase and chemical equilibria, mathematical modeling, and process calculations.A supercritical fluid is any substance at a temperature and pressure above its critical point where distinct liquid and gas phases do not exist. At this state the compound demonstrates unique properties, which can be "fine-tuned," making them suitable as organic solvents in a range of industrial and laboratory processes.This volume enables readers to select the most appropriate medium for a specific situation. It helps instructors prepare course material for graduate and postgraduate courses in the area of chemistry, chemical engineering, and environmental engineering. And it helps professional engineers learn supercritical fluid-based technologies and use them in solving the increasingly challenging environmental issues. - Relates theory, chemical characteristics, and properties of the particular supercritical fluid to its various applications - Covers the fundamentals of supercritical fluids, like thermodynamics of phase and chemical equilibria, mathematical modeling, and process calculations - Includes the most recent applications of supercritical fluids, including energy generation, materials synthesis, and environmental protection

Applications of Supercritical Fluid and Pressurized Water Extraction in Herbal and Environmental Sample Studies

Applications of Supercritical Fluid and Pressurized Water Extraction in Herbal and Environmental Sample Studies PDF Author: Qingyong Lang
Publisher:
ISBN:
Category : Extraction (Chemistry)
Languages : en
Pages : 200

Get Book Here

Book Description


Sample Preparation in Chromatography

Sample Preparation in Chromatography PDF Author: S.C. Moldoveanu
Publisher: Elsevier
ISBN: 0080540708
Category : Science
Languages : en
Pages : 949

Get Book Here

Book Description
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.

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 :

Get Book Here

Book Description


Supercritical Fluid Extraction and Its Application to Environmental Analysis

Supercritical Fluid Extraction and Its Application to Environmental Analysis PDF Author: WF. Beckert
Publisher:
ISBN:
Category : Environmental analysis
Languages : en
Pages : 13

Get Book Here

Book Description
Sand samples spiked with Aroclor 1232/1260, 17 organochlorine pesticides, 25 organophosphorus pesticides, 43 neutral/acidic compounds, and 16 PAHs were extracted with supercritical carbon dioxide at various pressures and temperatures to establish whether or not such type of compounds can be recovered from solid matrices by supercritical fluid extraction. A few Standard Reference Materials from NIST, spiked only with PAHs, were also evaluated.