Disposable polypropylene columns are prepacked with selective reversed phase, polar, and ion exchange organosilanes bonded to 40 μm, 60 ?, and 275 ? 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.