Thanks for spoonfeeding me, Rhodium and Chromic, it makes sense now. I have only one question left I hope someone has a minute to answer.
I posted a thread about a month ago in Methods in which I asked a question where SWIM had a bottle of GBL/Ethoxidiglycol mix which SWIM believed to be almost purely GBL. SWIM says he may have a lot of this. SWIM wanted to use this to make NaGHB, and (briefly) Rhodium suggested using another solvent to purify, Chromic suggested using NaOH to make NaGHB and then vacuum distill off the ethoxydiglycol.
Since the ethoxydiglycol is organic, miscible with water, has a boling point very very close to GBL - why can't SWIM use the same process to make NaGHB with this and then simply boil away the water/ethoxydiglycol that remains like what can be done with excess GBL/water? Why is low pressure distillation necessary? Since SWIM only has simple distillation apparatus, this potentially simpler method interests him.