Hardware manual

Maintenance 4
Agilent 7500 Series ICP-MS Hardware Manual 4-31
To resolve signal instability, complete the following steps:
1 Remove the nebulizer and end cap.
The sample uptake tube can remain on the nebulizer. Refer to the
“Disconnecting the Babington Nebulizer from the End Cap”
Remove the O- ring before soaking the nebulizer in acetone. Once the O- ring
is soaked in acetone, it will swell and installation will be difficult.
2 Soak the nebulizer for 10 minutes in acetone.
3 Soak the nebulizer for 10 minutes in methanol.
4 Dry the carrier gas and sample holes and remove any organic solvent
using argon or nitrogen gas.
If you start analyzing without drying completely, carbonate originated in
organic solvent may cause interference. If the signal instability still persists,
the nebulizer may be clogged or there may be leaks in the gas or sample
lines. Refer to 'To clean a clogged nebulizer' or check the connections for
leaks.
5 Check the O- rings.
Check the O- rings, which are located on the nebulizer and in the connector
between the nebulizer and carrier gas tube, and replace them if they are
cracked or too loose to seal properly. Wash the O- rings by immersing them
in pure water and dry them gently with a clean laboratory tissue.
If necessary, also replace the end cap O- ring, which is located inside the
nebulizer end cap, and the ferrules, which are located in the connector
between the nebulizer and carrier gas tube.
NOTE
If the gas tubing and sample introduction around the nebulizer leak even a small amount, it
causes a sharp signal fluctuation. To prevent leaks, be especially careful not to damage the
O-ring.