Supply Tubing For Hydrogen Gas - Agilent Technologies ALS Handbuch

Do not use methylene chloride or other halogenated solvent to clean tubing that will be
C A U T I O N
used with an electron capture detector. They will cause elevated baselines and
detector noise until they are completely flushed out of the system.
Do not use plastic tubing for suppling detector and inlet gases to the GC. It is
C A U T I O N
permeable to oxygen and other contaminants that can damage columns and detectors.
Plastic tubing can melt if near hot exhaust or components.
The tubing diameter depends on the distance between the supply gas and the
GC and the total flow rate for the particular gas. Tubing of 1/8-in diameter is
adequate when the supply line is less than 15 feet (4.6 m) long.
Use larger diameter tubing (1/4-in) for distances greater then 15 feet (4.6 m)
or when multiple instruments are connected to the same source. Use larger
diameter tubing if high demand is anticipated (for example, air for an FID).
Be generous when cutting tubing for local supply lines—a coil of flexible tubing
between the supply and the instrument lets you move the GC without moving
the gas supply. Take this extra length into account when choosing the tubing
diameter.

Supply tubing for hydrogen gas

Agilent recommends using new chromatographic quality stainless steel tubing
and fittings when using hydrogen.
• Do not re-use old tubing when installing or switching to hydrogen carrier
• Especially do not use old copper tubing, which can become brittle.
Do not use old copper tubing with hydrogen gas. Old copper tubing can become
WA R N I N G
brittle and create a safety hazard.
GC, GC/MS, and ALS Site Preparation Guide
gas. Hydrogen gas tends to remove contaminants left on old tubing by
previous gases (by helium, for example). These contaminants can appear in
output as high background noise or hydrocarbon contamination for several
weeks.
6850 Series GC Site Preparation
91