The vacuum distillation method for determining oxygen in alkali metals was applied to lithium. In this method the nonvolatile inpurities, assumed to be lithium monoxide, a r e separated from the volatile lithium by heating the lithium sample in high vacuum. The alkalinity o r the lithium content of the impurities is then converted to an oxygen concentration. Method reproducibility was determined a t the 30 and 80 ppm oxygen levels. Method accuracy was evaluated through quantitative oxygen additions and recoveries, estimation of the method blank, and characterization of the distillation residue from the lithium-oxygen system. SUMMA RYThe vacuum distillation method f o r determining oxygen in alkali metals has been applied to lithium. In this method the nonvolatile impurities, assumed to be lithium monoxide, a r e separated from the volatile lithium by heating the lithium sample in high vacuum. The alkalinity o r the lithium content of the impurities is then converted to an oxygen concentration.Method reproducibility for five lithium s e r i e s was found to be +? parts p e r million at the 30 parts per million oxygen level and *22 p a r t s p e r million at the 80 parts p e r million oxygen level. Method accuracy studies indicated (1) an average of 94 percent of the oxygen added to a lithium sample at the 138-and 276-microgram oxygen levels was recovered; (2) the method blank was found to be 0*3 micrograms oxygen over a lithium sample range of 0 . 3 to 1 . 2 grams; (3) the distillation residue, recovered from the lithiumoxygen system, was primarily lithium monoxide.ing technique for determining oxygen in lithium to levels less than 30 parts p e r million.The results of this investigation indicate the vacuum distillation method is a promis-

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Oxidation-reduction couples in concentrated solutions separated by appropriate ion selective membranes are an attractive approach to bulk electrical energy storage. A key problem is the developnent of the membrane. This report discusses four promising types of anienic membranes which were developed and evaluatd for the Redax Energy Storage System. The copoly rners af ethy leneglycoldimethacryhte w ;th either 2-viny lpyridine o r vinylbenzl chloride gave stable resistance values compared to the copolymer of vinylbemichloride and divinylbttxrzene which served a s the baseline ntembn.1~. A polyvinylchloride film aminated with tetraet\ylenepentamine had a low resistance J U~ a high iron transfer rate. A slurry coated vinylpyridine had the h e s t iron t r a d e r wte. A l l t\ese membranes functioned well in laboratory cells at ambient t e m p r a t u r e s witb the acidic chloride oxidan:,'reductant system.Fe III, F e I1 jTi m, Ti IV.