Complex mixture extraction

The market for flavours and aromas is large and was worth 16 billion in 2003 [7,8]. There are about 6,500 flavours known but of these only 300 are commonly used. At present 50-100 are produced by microbial fermentation, and many of the rest are chemically synthesised. In many cases, flavours and aromas are very complex mixtures extracted from pulp, bark, peel, leaf, bud, berry and flowers of fruit, vegetables, spices and other plants. The particular flavour or aroma will depend on the balance of these compounds, although a number are due to a single compound. 

Complex Mixture Extraction. Analytical SFE can also be used for complex mixture sample preparation. Typical examples using hazardous waste samples are described below. Sample A was a soil boring contaminated with coal gasification residuals and sample B was from a waste stream from a treatment facility. The major objective of these studies was to compare the extraction abilities (e.g., amount of material extracted) of three different fluid systems using approximately four-gram aliquots of the samples. The specific fluid systems, the extraction conditions, and the percentage of the total mass of material extracted from each sample are listed in Table II. 

Separation of classes of components. If a class of components is to be separated (e.g., a mixture of aromatics from a mixture of aliphatics), then distillation can only separate according to boiling points, irrespective of the class of component. In a complex mixture where classes of components need to be separated, this might mean isolating many components unnecessarily. Liquid-liquid extraction can be applied to the separation of classes of components. 

Mercuration has been also used as an extractive technique to separate thiazoles from complex mixtures such as crude petroleum (273. 861-863). 

Suppose we have a sample containing an analyte in a matrix that is incompatible with our analytical method. To determine the analyte s concentration we first separate it from the matrix using, for example, a liquid-liquid extraction. If there are additional analytes, we may need to use additional extractions to isolate them from the analyte s matrix. For a complex mixture of analytes this quickly becomes a tedious process. 

Carrageenan. The term carrageenan [19000-07-1] is the generic description for a complex mixture of sulfated polysaccharides that are extracted from certain genera and species of the class Fhodophjceae red seaweed. 

Any vegetable tanning extract used commercially is a complex mixture of related substances. The individual tanning properties of the extracts have been extensively studied and are weU known in the industry. 

Concretes and absolutes, both obtained by total extraction of the plant material and not subject to any form of distillation other than solvent removal, are complex mixtures containing many chemical types over wide molecular weight ranges. In some cases, gas chromatographic analysis shows httle volatile material. Yet these products have powerful odors and contribute in important ways to the perfumes in which they are used. 

Orange Flower. Extraction of freshly picked flowers of the bitter orange tree, dims aurantium (subspecies amard) for the production of concrete is carried out mainly ia Morocco and Tunisia. Most of this material is processed further to give orange flower absolute, one of the most important absolutes used ia perfumes after rose and jasmine. It is highly valued ia perfumery, even when used at low levels, for its long-lasting, rich, warm, yet dehcate and fresh floralcy. The material is a complex mixture, to which methyl anthranilate [134-20-3] linalool (3), methyl jasmonate (15), and iadole (16) are important odor contributors. 

Eor products having relatively low specific activity, such as some compounds labeled with and which are synthesized on the scale of several millimoles, classical organic chemical separation methods may be utilized, including extraction, precipitation, and crystallization. Eor separation of complex mixtures and for products having high specific activity, such as those labeled with tritium, etc, chromatographic methods utilizing paper, thin... 

Complex mixtures Tannery and Kraft mill effluent Sediment extract Sewage effluent... 

Wines and other alcoholic beverages such as distillates represent very complex mixtures of aromatic compounds in an ethanol-water mixture. Once an extract or concentrate of the required compounds is prepared, a suitable chromatographic system must be used to allow separation and resolution of the species of interest. Many applications have been developed that use MDGC. 

At the conclusion of the reaction, the resulting complex mixture of reagents and products can frequently be simplified by simple extraction into a suitable solvent, followed by appropriate washings. 

Because it does not have quite the same taste as the much more complex mixture of compounds found in natural vanilla extract, it is most often used with stronger flavors and scents such as chocolate, cloves, nutmeg, or cinnamon. 

The theory and development of a solvent-extraction scheme for polynuclear aromatic hydrocarbons (PAHs) is described. The use of y-cyclodextrin (CDx) as an aqueous phase modifier makes this scheme unique since it allows for the extraction of PAHs from ether to the aqueous phase. Generally, the extraction of PAHS into water is not feasible due to the low solubility of these compounds in aqueous media. Water-soluble cyclodextrins, which act as hosts in the formation of inclusion complexes, promote this type of extraction by partitioning PAHs into the aqueous phase through the formation of complexes. The stereoselective nature of CDx inclusion-complex formation enhances the separation of different sized PAH molecules present in a mixture. For example, perylene is extracted into the aqueous phase from an organic phase anthracene-perylene mixture in the presence of CDx modifier. Extraction results for a variety of PAHs are presented, and the potential of this method for separation of more complex mixtures is discussed. 

Cyclodextrin-modified solvent extraction has been used to extract several PAHs from ether to an aqueous phase. Data evaluation shows that the degree of extraction is related to the size of the potential guest molecule and that the method successfully separates simple binary mixtures in which one component does not complex strongly with CDx. The most useful application of cyclodextrin-modified solvent extraction is for the simplification of complex mixtures. The combined use of CDx modifier and data-analysis techniques may simplify the qualitative analysis of PAH mixtures. 

Separation of lutein esters from complex plant extract mixture... 

The identification of synthetic colorants (pure or mixtures) in foods is usually carried out using spectrophotometry but the resolution of complex mixtures in food requires a previous separation of extract components by SPE and chromatographic techifiques. Dual wavelength, solid phase, and derivative spectrophotometric methods combined with chemometric approaches have been used. ... 

These are found in crude petroleum including bitumen in the Athabasca tar sands of Northern Alberta. They contain a complex mixture of saturated polycyclic live- and six-membered cycloalkanes with alkane and alkanoic acid substituents. Attention has been directed to the degradation of both commercially available products, and those that are produced during bitumen extraction. Although the former were degradable (Clemente et al. 2004), the higher molecular mass components of the latter were much more recalcitrant (Scott et al. 2005). 

In the chromatography of plant extracts on an enlarged scale, there are a few main problems general elution because of the differentiated polarity of complex mixture components being separated the structural and chemical analogy of compounds and resolution decrease due to band broadening. 

W. Windig and H.L.C. Meuzelaar, Nonsupervised numerical component extraction from pyrolysis mass spectra of complex mixtures. Anal. Chem., 56 (1984) 2297-2303. 

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