Continuous extractors

Continuous Extractors. Continuous extractors are available in a variety of forms. The main difference between them is the way by which the soHds are transported through the equipment. For convenience the method of soHds transport is used as a means of equipment classification. 

Commercial supercritical fluid extractors have evolved in parallel with the consolidation of specific types of applications of the SFE technique [17]. By way of example of a commercial extractor and its changes over time, let us consider the one manufactured by Hewlett-Packard. This extractor has evolved from the oldest model (HP 7860 A, Fig. 7.3A), which was launched in 1992, to the present one (HP 7680 T, Fig. 7.3B). Essentially, however, the extractor continues to consist of the following elements ... 

Ethynylmagnesium bromide, 39, 56 reaction with acrolein, 39, 58 with aldehydes and ketones, 39, 57 with crotonaldehyde, 39, 58 with methyl ethyl ketone, 39, 58 Extraction apparatus, Kies, 37, 30 Extractor, continuous, 30, 4... 

This extractor continuously cycles the sample steam distillate through an immiscible lighter-than-water solvent such as hexane. Routinely, large volumes of sample (4000 mL) can be distilled/extracted in a 5 mL volume of solvent. Emulsions and interferences that are commonly observed in an extraction are reduced or eliminated entirely. Normally, species that can be steam distilled can also be gas-chromatographed. This results in a cleaner extract and reduces the build-up of residue in the injector of the gas chromatograph. A prediction of whether or not a particular compound will steam strip from water can be made on the basis of its relative volatiUty to water ... 

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