Whelk-O 2 has the same chiral selector as Whelk-O 1 but incorporates a trifunctional linkage to the silica support. In most cases, the enantioselectivity remains the same as that obtained with Whelk-O 1. Whelk-O 2 was designed to improve the resistance of the stationary phase to hydrolysis while using strong organic modifiers such as trifluoroacetic acid. Whelk-O 2 is ideal for preparative separations since the material is bonded on 10 µm, 100Å spherical Kromasil silica. This allows the preparative chromatographer to perform method development on an analytical column and immediately scale up to larger diameter columns.