HPLC Column Xtimate C4, 5 µm, 3.9 x 300 mm, old number 21107-21035

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.