YMC is pleased to introduce Exphere, a new family of bulk packing materials, specifically designed for preparative liquid chromatography. Exphere combines YMC’s novel high strength silica with a special polymeric surface modification technique.
The perfectly spherical particle shape and extremely narrow particle size distribution makes column packing easy and gives
very low operating pressures even at high flow rates. This makes Exphere ideal for use in (dynamic axial compression) DAC columns and also Kronlab glass columns.

Silica packings that are used in production often have to withstand great mechanical stress during column packing and during use in DAC columns. Mechanically instable particles can crush and form fines. As a result, the column pressure will increase. Eventually the pressure limit for the column will be reached, and it will have to be unpacked and repacked with new material. For a trouble-free and economic process, high mechanical stability of the silica particles is crucial.

In order to prove the mechanical stability, Exphere C8 and a conventional C8 phase were packed repeatedly in a DAC column. The increase of column pressure is a measure of the degree of degradation of the material after the repeated packing cycles.

Exphere particles are totally spherical and have a smooth surface. Their enhanced mechanical stability allows for higher packing pressures, which gives more stable and efficient column beds and results in increased column lifetime.

For the purification of biopolymers such as peptides and proteins, low pH eluents often have to be used. These conditions are very demanding for the chemical stability of the packing material.

The Exphere bonded phases C18, C8 and C4 are characterised by a special polymeric surface modification technique. This gives an outstanding stability against hydrolysis even at low pH, resulting in remarkable increased lifetimes and cost efficiency.