Traps - Agilent Technologies 6890 Series Service Manual

520 Gases
The gas plumbing

Traps

Using chromatographic-grade gases insures that the gas in your system is
pure. However, for optimum sensitivity, it is highly recommended that you
install high-quality traps to remove traces of water or other contaminants.
After installing a trap, check the gas supply lines for leaks.
Table 520-4
Description
Preconditioned moisture trap: metal casing, s-shaped trap for carrier gas cleanup.
Contains Molecular Sieve 5A, 45/60 mesh, and 1/8-inch fittings.
Hydrocarbon trap: metal casing, s-shaped trap filled with 40/60 mesh activated
charcoal, and 1/8-inch fittings
Oxygen trap (for carrier and ECD gases): metal casing, and 1/8-inch brass fittings.
Oxygen trap cannot be reconditioned.
Moisture in carrier gas damages columns. We recommend a type 5A Molecular
Sieve trap after the source regulator and before any other traps.
A hydrocarbon trap removes organics from gases. It should be placed after a
molecular sieve trap and before an oxygen trap, if they are present.
An oxygen trap removes 99% of the oxygen from a gas plus traces of water. It
should be last in a series of traps. Because trace amounts of oxygen can
damage columns and degrade ECD performance, use an oxygen trap with
carrier and ECD gases. Do not use it with FID, FPD, or NPD fuel gases.
Molecular sieve or hydrocarbon trap—both are S-shaped
Figure 520-3
8 of 14
Recommended Traps
Traps
Site Preparation
Agilent 6890 Gas Chromatograph Service Manual
Part No.
5060-9084
5060-9096
3150-0414
Oxygen trap
Jun 2001