Graphite is the best material to work at high temperature and at the same time is the softest ferrule. Therefore it fits the capillary column and seals effectively at only ¼ turn past fingertight. As this is a very soft material, thery are easily destroyed or deformed. Ideal for FID and NPD detectors. Do not use with MS or other oxygen sensitive detectors.
Upper temperature limit 450ºC.
Vespel /Graphite ferrules are recommended for applications with GC/MS interface or other oxygen sensitive detectors.
The ferrule composition is 60% polymide and 40% graphite. It is a ferrule for general use in Gas Chromatography.
It is mechanically robust and forms a perfect seal. It is a reusable ferrule. It needs a frequent retightening. Limit temperature 400ºC
85% Polymide (vespel) 15% graphite for Agilent ferrules.
The composition of the Vespel ferrule is 100% polyimide.
It is mechanically robust. It can be removed and reused several times. It is an ideal material for glass and metal columns.
It needs a frequent retightening. Limit temperature 350ºC.