Focused open-vessel microwave-assisted extraction

Weichbrodt et reported on the use of focused open-vessel microwave-assisted extraction (EOV-MAE) for the determination of organochlorine pesticides in high-moisture samples such as fish. The results were comparable to those with closed-vessel microwave-assisted extraction (CV-MAE) and ASE. The main advantage of FOV-MAE is that the use of Hydromatrix is unnecessary as the solvent mixture of ethyl acetate and cyclohexane allows the removal of water from the sample matrix via azeotropic distillation. 

Weichbrodt M, Vetter W, Scholz E, Luckas B, Reinhardt K (1999) Determination of Organochlorine Levels in Antarctic Skua and Penguin Eggs by Application of Combined Focused Open-Vessel Microwave Assisted Extraction, Gel-Permeation Chromatography, Adsorption Chromatography, and GC/ECD. Inter J Environ Anal Chem 73 309... 

Most studies about the microwave-assisted extraction of PAHs from solid samples have been conducted using closed-vessel systems [12,214,226,236,239-246] and only a few with open-vessel focused microwave devices [57,247-252]. Because open-vessel systems operate at atmospheric pressure, the extraction vessel can be used as a reactor in order to perform on-line purification pretreatments of the total extracts (reagents can be readily added to the medium) [53] or directly introduce the extract into the determination instrument, as in the focused microwave-assisted extractor with on-line fluorescent monitoring of Fig. 5.10, which provides a matrix-independent approach to the extraction of PAHs [61]. 

Shu, Y. Y., Lai, T. L., Lin, H., Yang, T. C., and Chang, C., Study of factors affecting on the extraction efficiency of polycyclic aromatic hydrocarbons from soils using open-vessel focused microwave-assisted extraction, Chemosphere, 52, 1667-1676, 2003. 

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