Apparatus and method for reversed permeation membrane extraction of compounds from sample solutions

摘要

A reversed permeation membrane assembly and method for collecting one or more compounds of interest from a sample solution. The membrane assembly includes a semi-permeable membrane of predetermined thickness and length, and having inner and outer surfaces. The membrane is attached adjacent its outer surface to a substantially rigid membrane support, and a non-porous barrier contacts the outer surface of the membrane to prevent permeation of compounds beyond the outer surface in use. In a preferred embodiment, the semi-permeable membrane assumes a substantially tubular conformation through which sample solution may be passed. The membrane support also preferably features a tubular conformation within which the semi-permeable membrane is mounted. Because of its unique structure and improved efficiency, the assembly of the present invention may be incorporated for in-line use with liquid and gas chromatography devices and GC/MS units. In some applications, the extractant can even be flowed through the membrane cell to collect analytes and directly to an LC column for analysis in a substantially non-stop manner.