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Quadrupole MS cleaning

Posted: Wed Oct 11, 2006 11:19 pm
by NG
I would appreciate if anyone can suggest me how to clean Quadrupole metal rods and how to take them apart. I have Unicam's Nermag Automass (610/615) instrument and I don't have its manual. If anyone has manual for this/similar model that will be very helpful.

Thanks.

Posted: Thu Oct 12, 2006 9:32 am
by gcguy
With the Agilent system if you take apart the quad rods I believe you then have scrap!
The alignment of the rods is crytical to the operation of instrument so I would be tempted to get in touch with the manufacturer to gain some guidance.
The gcms systems I use have never had the rods cleaned and they work ok, the source however does require cleaning and this is a relatively simple task.

GCguy

Posted: Mon Oct 23, 2006 12:53 am
by james little
Some of our instruments never need the quadrupoles cleaned under normal circumstances.

Some have prequads that are cleaned.

However, the Finnigan TSQ70/700 which we purchased in 1988 needs the quads cleaned every one to two years. We take the quads apart and clean lightly with an abrasive such as 3m paper or Ajax with a Qtip. Then wash them very well with water, then methanol or acetone. Then blow off with nitrogen or some other clean/nontoxic gas.

Then usually hold up to light at different angles to make sure they are clean of all residue. Finnigan supplies a jig to allign the quadrupole. However, you need to be very careful in how much you tighten the screws in the insulating collars on the quadrupoles. Think you tighten all the way then loosen a 1/2 turn? or something like that.

For the very first years on the Finnigan, we just cleaned the ends of the quads closer to the source with an abrasive with either the Q-tip cotton tip or by breaking the Q-tip stick and using abrasive on the end of the stick. Most of the burn noted on end of quad since no prequad with this system. We had very long Q-tips which we used I think with methanol to wash the rest of the Quad. Then backflush the quadrupole assembly thoroughly with water from the faucet. Hold up in light and make sure no abrasive film noted, then wash with methanol or acetone to dry the rod. Think we put in the GC oven 1t 50 C lighly wrapped in tinfoil for 5-10 minutes to dry, then blow off with gas.

Either method seemed to work fine, the latter probably involves much less risk. Have probably done the former procedure about 10 times and the latter one about 4 times.

If you take the QUads apart, be sure to note which rod was in which holder, and place back exactly the same. I think our quad rods had serial numbers on the end of the rods.

Instrument still running routinely today, replacing soon with another instrument, but work reasonably well doing routine GCMS EI and CI.

Dan Gartiez use to have some Nermag instrumentation, maybe you could contact him for some tips..

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