Restek ultra selective liquid chromatography columns

Restek ultra selective liquid chromatography (USLC) columns offer a wide range of selectivity using just four stationary phases, providing the practising chromatographer with tools for choosing columns fast and developing methods faster.

One of the most significant, yet least understood, steps of method development is finding the proper stationary phase for a particular separation. As sample complexity increases, achieving adequate resolution between matrix components and target analytes becomes more difficult.

Despite recent advancements in column format, such as sub-2 micron packings and pellicular particles, resolution can still be difficult to obtain because, while these formats can increase chromatographic efficiency and analysis speed, they do not significantly influence resolution. Selectivity is the single most powerful factor affecting resolution, and it is largely dependent on stationary phase composition.

While numerous bonded phases are available for reversed phase chromatography, many (eg, C8 and C18) are similar and offer only moderate changes in retention, rather than significant differences in selectivity. Method development is less laborious and time-consuming when using a full range of column selectivities, including orthogonal phase chemistries like polar embedded, phenyl and fluorophenyl columns. The USLC column set has been developed across these phase classes to provide analysts with a more effective range of column selectivities and innovative column chemistries for method development.

The column set provides what is claimed to be the widest range of reversed phase selectivity available with just four columns - the Aqueous C18, Biphenyl, Polar embedded IBD and Pentafluorophenyl Propyl - and can be used to guide proper stationary phase selection; the least understood yet most significant part of method development.