“…Similar use of fractionation has been reported by the Bureau of Mines and others {83, 126, 147). Various complete fractionating columns have been developed or improved for general laboratory use {40, 52,61,66,69,85,90,98,113,131,136,141,143). Extensive application of precise fractionation has also occurred in the development of fluorine chemistry {11, 50, 104).…”