<p>Air-free filtration
</p><p><br><u>Apparatus</u>:
</p><p>a = receiving <a href="//commons.wikimedia.org/w/index.php?title=Schlenk_flask&amp;action=edit&amp;redlink=1" class="new" title="Schlenk flask (page does not exist)">Schlenk flask</a> (pink joint)
</p><p>b = glass filter sinter/frit
</p><p>c = filter stick 
</p><p>d = sealing bulb
</p><p>e = suspension containing <a href="//commons.wikimedia.org/w/index.php?title=Schlenk&amp;action=edit&amp;redlink=1" class="new" title="Schlenk (page does not exist)">Schlenk</a> flask (blue joint)
</p><p>f = stopper
</p><p><u>Method</u>
</p><p>1 = Dry apparatus and place under vacuum. 
</p><p>2 = Place filter stick and receiving flask (pink joint) on suspension containing flask (blue joint). Solution (blue) precipitate (green).
</p><p>3 = Invert kit, light vacuum applied to lower flask, top flask sealed. Liquid passes through sinter. Precipitate trapped on sinter. Optionally, the precipitate can be washed with fresh solvent.
</p><p>4 = Filtration complete, remove vacuum and fill with inert gas from top Schlenk flask
</p><p>5 = Remove filter stick to obtain filtered solution (blue). 
</p>
(Note if precipitate (green) is required this can be collect either (i) in a glove box, or (ii) by tapping the solid back down into (blue jointed) Schlenk flask under gravity (as shown in the drawing), or (iii) adding a new Schlenk flask to the end of the filter stick which is opposite to the blue jointed Schlenk flask, and by washing a dissolving solvent through filter stick to dissolve the precipitate and thereby transfer the precipitate into the fresh Schlenk flask.  The solvent can then be removed under vacuum.)
Original PNG by <a href="//commons.wikimedia.org/w/index.php?title=User:Quantockgoblin&amp;action=edit&amp;redlink=1" class="new" title="User:Quantockgoblin (page does not exist)">User:Quantockgoblin</a>, SVG adaptation by <a href="//commons.wikimedia.org/wiki/User:Slashme" title="User:Slashme">User:Slashme</a>
Re-drawn from work by <a href="//commons.wikimedia.org/w/index.php?title=User:Quantockgoblin&amp;action=edit&amp;redlink=1" class="new" title="User:Quantockgoblin (page does not exist)">Quantockgoblin</a>