Distilling small volume
In order to both achieve sufficient separation and minimize loss during fractional distillation, you want 


a large inner column surface for optimal contact of the vapour phase (upstream) and the liquid phase (downstream)
a rather small inner column volume


Often, these destillation are performed using a Spaltrohr distillation apparatus. Here, the vertical column consists of two concentrical, threaded glas tubes with a gap of 1-2 mm  in between.