ZORBAXExtend-C18 Extend-C18columnsincorporateauniquepatentedbidentatesilane,combinedwithadouble-endcappingprocessthatprotectsthesilicafromdissolutionathighpH-uptopH11.5.columnsarebestappliedforseparationsofcompoundsthatareeither(1)basicandhavelittleornoretentionatloworintermediatepHs,(2)morestableormoresolubleathighpH,or(3)basicandshowpoorpeakshapeatloworintermediatepH.