ZORBAX optimized phases are now available in preparative dimensions as PrepHT columns. These columns are 21.2 mm and larger in diameter with 5 µm and 7 µm particles to provide high resolving power. They are also available in various lengths to allow optimum resolving power and speed of analyses. In preparative chromatography, it is important to obtain high purity and high recovery along with high throughput. Agilent ZORBAX PrepHT columns have a broad range of selectivities to achieve these objectives.