*** 9660590 Fatunmbi The purpose of this proposal is to develop novel chromatographic stationary phases on horizontally polymerized C18/C1 monolayers. The new chromatographic stationary phase has the potential to affect significantly both the performance and stability of commercial columns for high-performance liquid chromatography. The novel phase provides exceptionally low silanol activity and high hydrolytic stability, two critical features that are unsatisfactory in presently available columns. The commercial viability of these phases will be evaluated in a systematic comparison to present commercial products with respect to chromatographic performance and hydrolytic stability. This approach has the potential to provide new classes of stationary phases that can be marketed through the leading chromatography companies. ***