Disposable polypropylene columns are prepacked with selective reversed phase, polar, and ion exchange organosilanes bonded to 40 µm, 60 Å, and 275 Å silica gel absorbents and size exclusion gels

The highly surface-active sorbents, contained by two 20 µm polyethylene frits, provide high capacity. This configuration allows extraction of compounds from sample solution volumes of a few hundred microliters to several milliliters.