Ferrule materials and fittings

It is important to select the proper ferrule i.d. to be compatible with the o.d. of the capillary column, or a carrier gas leak will result after installation. Ferrules with an i.d. of 0.4 mm are recommended for 0.25-mm-i.d. columns, 0.5-mm-i.d. ferrules are recommended for 0.32-mm-i.d. columns, and 0.8-mm-i.d. ferrules are recommended for 0.53-mm-i.d. capillary columns. 

Outlined below are guidelines for the preparation of a capillary column for installation. 

Slide the retaining fitting or nut over the end of a new column, then the ferrule, and position them at least 6 in. away from the column end. It will be necessary to cut several inches from the end of the column because ferrule particles may have entered the column and can cause tailing and adverse adsorptive effects. 

---