# The Matrix Parameters of the Stationary Phase of Flash Columns

The stationary phase, commonly known as the fillers, is the most central part of chromatography. People need to determine three aspects of stationary phase information in turn before determine how to select the kind of the stationary phase of the flash purification column. They are matrix type, surface modification/bonding phase, and matrix parameters.

Here we talk about the matrix parameters. Matrix parameters include matrix shape, particle size, and pore size. These parameters should be selected according to the specific requirements of purification.

The size of the matrix directly affects the efficiency of **flash columns** and the separation effect. The smaller the particle size is, the higher the column efficiency is. The selection of the size depends on the separation condition of the samples. And generally speaking, the price of the stationary phase depends on the particle size.

In general, large particle stationary phases are often chosen when the samples need to be purified crudely. While the sample has high added value and requires high purity, the small particle stationary phases are mostly selected.

In a word, the choice of particle size of stationary phase should be considered comprehensively from the cost, sample and purification equipment parameters.