The hybrid particles based Xtimate® phases are bonded using our improved bonding process. Surface bonding coverage for hybrid particles uses a new organic silane with a more reactive group for bonding and endcapping.
Besides C18 and C8 bonded phases, Xtimate also provides C4, CN, Phenyl bonded phases. Xtimate® applies a new special SmoothpakTM technique to C18, C8, C4, CN, Phenyl and amino phases, different than the bonding method of other series. As a result, Xtimate® provides a different selectivity, improved stability and reproducibility. In particular, for the Phenyl phase of Phenyl-Hexyl, Xtimate® is totally different from Ultisil® Phenyl. Xtimate® Phenyl phase’s longer hexyl group provides extra hydrocarbon interaction and longer retention than conventional phenyl-propyl phase; it also provides better chemical stability. Welch also adds polar embedded phase, Polar-RP on Xtimate® particles, to further improve peak shape for very polar and strong basic compounds and provides different selectivity than does C18 phase.