HPLC Columns Separation Principle

HPLC columns can be divided into analytical and preparative types according to their applications, and their size specifications are different:
1. Conventional analytical column (constant column), inner diameter 2~5mm (commonly used 4.6mm, domestic 4mm, and 5mm), column length 10~30cm;
2. Narrow bore (also known as the thin bore, semi-microcolumn), the inner diameter of 1 ~ 2mm, column length 10 ~ 20cm;
3. Capillary column (also known as microcolumn), inner diameter 0.2~0.5mm;
4. Semi-preparative column, inner diameter > 5mm;
5. Laboratory preparation column, inner diameter 20~40mm, column length 10~30cm;
6. Production preparation column inner diameter up to several tens of centimeters.

The inner diameter of the column is generally determined by the length of the column, the particle size of the filler, and the flow rate of the fracture, in order to avoid the wall effect.

HPLC column separation principle

The separation principle of the HPLC columns is to use the components in the sample to have different partition coefficients between the mobile phase and the liquid phase of the stationary phase. Under the carrier gas, the components are repeatedly distributed between the two phases, because the components are The force in the column is different. After a certain column length, it is separated and flows out of the column.