Removing Solids From The Nebuliser - Thermo Scientific iCAP 7000 Series Manual

iCAP Customer Familiarisation Manual

10.5 Removing solids from the nebuliser

If solids inside the nebuliser are interfering with performance of the system, the
steps described below will generally remove them and provide normal operation.
10.5.1 To rinse the nebuliser
Introduce a rinsing agent into the shell, either from the gas input or the nozzle (a
squeeze bottle works well in both cases). Fill all areas previously exposed to
corrosive solutions.
Attach pressurised gas to the side-arm to expel the liquid.
Inject more rinse solution into the liquid input while the gas is flowing and allow
venture suction to draw it through the capillary.
The final rinse should use isopropyl alcohol to speed the drying process.
Repeat the treatment if you think it is necessary.
After the rinse is complete, dry the nebuliser completely
10.5.2 Particles
These operations are ranked in order of increasing aggressiveness. We recommend that
you start with the gentlest procedure and continue with more aggressive procedures as
.
required
Tap the liquid input line of the nebuliser gently against a wooden surface (or a
surface of comparable hardness) to shake the particle loose. This helps the particle
to move in the direction of increasing inner diameter. Repeat the tapping as
necessary to work the particle toward the appropriate exit orifice. Avoid extremely
.
harsh tapping
Apply compressed gas (15-30 psi) to the nozzle, forcing the gas backwards through
the annulus and the capillary (back flushing).
Note: Make sure the nebuliser is held securely during this operation.
Gently tap or flick the shell soundly with your fingernail a few times. If this fails to
dislodge the particle, close off the liquid and gas input tubes with your fingertips.
When the pressure builds up, move your fingertip quickly off the appropriate orifice
(if something is wedged in the gas annulus, "pop" your finger off the gas input; if in
the capillary). The sudden expansion of gas should help jar the particle loose in the
direction of increasing inner diameter. Try to orient the nebuliser so that gravity
assists you.
Force isopropyl alcohol backwards through the nozzle in an attempt to float the
particle out through the larger gas and liquid input tubes. Use a squeeze bottle or
plastic dropper with a tip that will form a good seal over the nebuliser nozzle. After
the particle has been removed, remove the alcohol through the input tubes using
compressed gas, or drain onto lint-free tissue. A variation of this procedure involves
the use of a solvent that is known to dissolve the particle (this variation works best if
you know which passage the particle is in and your nebuliser is a type C or K with a
recessed capillary. In this procedure, inject a slug of 1/4" to 1/2" of solvent into the
shell through the nozzle or the gas input tube and close off the nozzle with a
fingertip. Apply pressurised gas to the passage that does not contain the particle.
Pressurised solvent will force its way out the other channel in the direction of
increasing diameter, hopefully carrying the particle along with it).
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