Removal of dissolved O-2 by a fluid membrane of Fomblin Y (perfluoro polyether): fluorescence of diphenylhexatriene in Fomblin Y

O-2 can be gently removed from solutions by contact with a ''bulk fluid membrane'' of the viscous and nearly inert perfluoro polyether Fomblin Y. A volume of Fomblin dissolves similar to 20 times more O, than an equal volume of water. Hence, when a volume of aqueous solution which was in equilibrium with air is enclosed with an equal. volume of Fomblin which had been flushed with argon, oxygen would diffuse into the Fomblin, leaving in the water only 5% of the oxygen that was there. When the Fomblin is stirred, diffusion is rather rapid. The residue can be removed either by placing an oxygen scavenger on the other side of the Fomblin or by flowing a trickle of deoxygenated Fomblin through the sample. Diphenylhexatriene a fluorescent probe of cell membranes, can be dissolved in Fomblin Y and has a fluorescence Lifetimes extending from 12 ns in O-2 saturation to 30 ns (!) in the absence of oxygen. Stern-Volmer plots calibrated against a Clark electrode validate this system for oximetry. A general purpose anaerobic cuvette for fluorescence spectroscopy, containing the sample solution, a Fomblin compartment and the oxygen scavenger Na-dithionite is demonstrated. (C) 1997 Elsevier Science B.V.