https://doi.org/10.1351/goldbook.10279
Narrow cylindrical tube prepared from a porous polymer.
Note: The internal diameter of the tube is typically \(\pu{500 \upmu\!m}\) – \(\pu{1.5 mm}\) with walls \(\pu{100 \upmu\!m}\) to \(\pu{300 \upmu\!m}\) thick. Fibers are typically prepared from porous poly(propylene), although other materials can be used.