More than 80% of reversed phase HPLC analyses are accomplished on octyl- or octadecyl-phases. Due to this overwhelming majority, many chromatographers neglect other selectivities that might be better suited to their separation e.g. butyl phases. Compared to a C18-phase with the same eluent, this less hydrophobic (C4) material gives shorter retention times for non-polar compounds while the retention time of polar analytes are virtually unaffected. This makes the YMC Pack Pro C4 an interesting alternative especially when short analysis times are required.

For this reason, mixtures with a wide range of analyte polarity are best separated by short chains, such as C4. The comparison below shows that YMC-Pack Pro C4 is the column of choice when fast HPLC is required. There is almost no difference in retention times for the first three compounds whilst Nicardipine HCL elutes faster on YMC-Pack Pro C4 due to its lower polarity.