Filter probe extractor

Tomlinson, E., and T. Hafkensheid. 1986. The Filter Probe Extractor A Versatile Tool for the Rapid Determination of Solute Oil/Water Distribution Behavior. In Partition Coefficient Determination and Estimation, W.J. Dunn III, J.H. Block, and R.S. Pearlman, Eds., 83-99, Pergamon Press, N.Y. 

Barnett et al. (1992) have described a method for estimating partition coefficients from data collected using a filter probe extractor. They developed the method to analyze data from two component mixtures (e.g., in the presence of an impurity) for which there existed no suitable method. The technique is based on model fitting and may also be used for pure compounds. 

The solid-solvent mixture is stirred or shaken and then filtered or centrifuged to separate the matrix. Typically three extractions, using small portions of solvent, are needed to assure quantitative extraction. Heating may help in some cases. Or ultrasonic energy (ultrasonic batch or ultrasonic probe) can be used to increase efficiency. Continuous Soxhlet extraction is often used. A Soxhlet extractor has a round-bottom distillation pot, with a porous thimble above it in a siphon chamber, into which the sample is placed. Solvent is continuously cycled through the sample by distilling the solvent to a condenser centered over the thimble. The condensed solvent permeates through the matrix and the thimble, and is siphoned back into the pot, where it is recycled. The extracted material is concentrated in the pot. 

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