Xtimate UHPLC C18 (USP L1) is a 1.8 micron hybrid stationary phase synthesized with octadecyl silane. Xtimate UHPLC C18 is 14% carbon loaded, giving it selectivity distinct from Ultisil UHPLC C18. In addition, Xtimate UHPLC C18 provides the widest useful pH range of the UHPLC phases: 1.0 – 12.5 pH.