Gas/Liquid and Liquid/Liquid Solvent Extraction in Flow Analysis with the Chromatomembrane Cell

Since twelve years the Chromatomembrane Cell has been proposed as a new andversatile device for extraxtion procedures in the flow based analysis. In the meantime aremarkable number of papers was submitted dealing with applications of the novel methodto all the conceivable varieties of flow injection and sequential injection analysis. Thedevice supports important analytical procedures such as sampling, sample preparation, andpreconcentration each being combined with a phase transfer of the analyte. TheChromatomembrane Cell can be coupled to most of the modern detectors which workcomputer aided in the laboratories of today. Centrepiece of the cell is a block made frombiporous hydrophobic PTFE, inside which polar (in the macropores) and nonpolar (in themicropores) solvents come into a close contact with each other and might flowindependently with different flow rates. Microporous PTFE membranes prevent polarphases from their flowthrough into directions which are reserved for nonpolar fluids only.Thus, a strict control over the fluxes can be established at the analysts request. Especially,that PTFE block offers outstanding possibilities as a sampling unit for air monitoring.