Freon-12 as an Oxygen Scavenger It hss been fonnd in our laboratories that Freon-12 (CCISA)is a satisfactory and convenient replacement for nitrogen for removing dissolved oxygen from aqueous solutions, as for polarogt.aphy. I t is available through dealers in refrigeration supplies in one-pin1 pressurized cans a t less t,han one dollar per can. A special needle valve which can be transferred from one can to another sells far less than fonr dollars. Thc advantngm are several. The small can is much more convenient and less hazardous than the conventional large nitrogen cylinder. The Freon gas has about four times the density of nitrogen, and hence is more easily utilized to blanket a solotion. Furthermore, oxygen is swept out in a much shorter time than with nitrogen, other factors being equal. The Freon is completely inert under the conditions of use. The oxygen waves visible both by conventional polarography and cyclicvoltammel.ry (in 0.1 F KCI) are eliminated wit,h Freon just as completely a5 with nitrogen.
G.LLENW. EWING
292
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Journal o f Chemical Education
