MSD Quad Disassembly Procedure?

[fomalhaut]

Please advise on 5971/5972 MSD quad disassembly procedure; may need to clean rods but can't see enough of the surfaces to tell; have disassembled ion traps many times but never rod quad.

[Ron]

In these instruments there are no classical quadrupole rods, there is a monolithic quartz piece that is metallized in precise areas to function as the quadrupole. This is not designed to be cleaned, but to be replaced if it becomes contaminated. I am not sure that this can be cleaned without damaging it.

[fomalhaut]

Thanks for your reply. I have read other posts from the archives which indicate the rods from the HP 5971 MSD quadrupole are indeed polished metal rods so your reply confuses me somewhat. From all apppearances they look visually like approximately 1/4" diameter solid steel rods separated from each other by gold colored or plated thin metal curved plates as far as I can see without actual disassembly. I am most concerned about getting them realigned after disassembly. I will await further replies to make a decision.

[Ron]

Here is a description I found of the standard 5971, There were kits to allow a person to replace the quartz mass analyzer with a true quadrupole rod array, but I have never actually seen one.

HP 5971A Mass Selective Detector General description:
The HP 5971A Mass Selective Detector (MSD) is a stand-alone capillary GC detector designed for use with the HP 5890A gas chromatograph. i is compact and portable (mainframe weighs 21 kg), requires no cooling water or compressed air, and operates on 110/120 volts or 220/240 volts power. The MSD mainframe includes the GC interface, electron impact ion source, monolithic quartz hyperbolic quadrupole mass filter, electron multiplier detector, power supply, drive electronics, and analyzer vacuum system. The MSD is configured for a right-side sample inlet.

[CE Instruments]

I think you may be mistaken. The 5970 MSD did have true metal quadrupole rods but the later 5971, 5972, 5973 and current 5975 all use a Monolithic Quartz quadrupole. If you have solid rods you have a 5970 not the later "shoebox " 5971

[AICMM]

With the old 70's, I left the quads assembled and dipped the whole assembly into a grad cylinder of methylene chloride. That was relatively straight forward. I do not know if the same is possible of the 71's, 72's, etc... but you should be able to ask Agilent. I would vigorously argue against trying to disassemble the quads in any other way.

By the way, cleaning did almost nothing. Ended up dipping that same set of quads (after long argument with HP service engineer, long ago) and they worked much better after that. Much easier to dip quads than clean quads....

Best regards.

[Rick]

Hi!
You can clean your quad if it is Monolithic Quartz quadrupole.
You clean it with dichloromethane
Don't forget, it is very important.....don't use Ultrasonic bath.
and you must replace the quad exactly in the same position.
After reinstallation, you need to redip your quad

Before to do that, try to bake-out your quad....often, bake-out resolve some problem....verify what is the max temperature you can use.