From http://www.rhodium.ws/chemistry/birch.mrclean.html :

"Why can't I just use aqua ammonia? Li will reduce pseudo in the presence of H20.

(Answer provided by Osmium)
Li + H2O -------> LiOH + 0.5 H2
Li [6g/mol]
H2O [18g/mol]
For every gram of H2O present you need at least 0.33g Li.
So what if I used 1l of 30% NH3? Cool, only about 250g of Li needed to dry it! And don't forget the liquid N2 to cool this bomb... "

I've got two questions:
1. Is it possible to use 30% ammonia for small batches(4g or so).
2. I heard that a push/pull won't work with pfed sulfate, why?