Solid-liquid extraction technologies equilibrium

All chapters, especially the last two, contain information that has not been published previously. The chapter on solid-liquid extraction technologies, for example, presents and discusses both theoretical and practical aspects of these technologies, from fundamental concepts of equilibrium and mass transfer to equipment selection and design. Similarly, the chapter on safety of botanicals reviews safety issues of botanicals associated with misidentification of plant species, misuse of products, product adulteration and botanical/drug interactions. 

Many phytochemicals and nutraceutical ingredients are derived from botanicals. In the manufacture of many of these nutraceuticals, processes begin with the extraction of plant materials using a suitable solvent. Many technologies and types of equipment exist to achieve this solid-liquid extraction. To successfully choose and operate the proper equipment for producing the desired product in an economic manner, the fundamentals of equilibrium and mass transfer must be understood. Once these fundamentals are understood, they can be applied to the botanical raw material of interest and the chemical properties of the desired phytochemical to select and operate the most cost-effective extraction equipment. 

If the components of interest in a solid or liquid sample are volatile, a good way to analyze them is to examine the concentration of these analytes in the gas phase above the matrix (headspace) when in a closed container, either by taking a sample directly from the gas phase or trapping and concentrating the gas prior to analysis. This type of extraction techniques are known as headspace analysis (Smith, 2003) the analysis and subsequent separation of volatile substances is normally carried out by the technique of gas chromatography, which is a mature technology, reliable and supported by a large body of work. The sample can be in contact and in equilibrium with the extractant gas (static or equilibrium headspace), or volatile compormds can be extracted by a steady stream of inert gas (dynamic headspace). 

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