Chromatography Forum

If I use Flitz auto polish to clean MSD parts and only sonicate in Meoh.....What problems could I see? Thanks Ken

If you read the MSDS for the flitz auto polish, you will see that you are putting more than just alumina and a volitile solvent on your source parts. Y0u will include hydrocarbons, fattay acids and other stuff. These are not going to be removed well by methanol - and are likely to be retained on the surface of the source parts.

To properly clean the source, you must use a sufficiently fine grade of grit to provide suitalble polish on the metal surfaces. The grade of grit is not indicated in the MSDS for the auto polish.

Using only methanol for sonication: you will only remove compunds that come off easily in methanol. There is a reason the other solvents are used -- to clean off all kinds of other stuff.

I suggest following manufacturer's directions. They have been shown to work well. On MSDs I've used, these basic instructions have stood the test of time for over 25 years. I am trying to remember if there were some modifications (by the vendor) before that - if so, they were minor.

I would recommend against. The alumina powder is a pain to use but the results speak for themselves.

I've used Autosol polish for years to clean my sources. I rinse parts regularly with hexane duing cleaning to prevent a buildup of polish and sonicate a number of times in hexane until it remains clear, then sonicate in acetone and methanol and bake parts before reassembly.

If you use someone's pet recipe for cleaning, you know it works for ever application they carry out on their instrument. It may, however, leave the MSD contaminated with something (particularly components of Jim's Patent Beetle Polish) that happens to interfere with something you decide to measure, if you are unlucky. If you use the manufacturer's recipe for cleaning, you know it's a recipe that works for all their customers. That probably makes it a very reliable recipe, although possibly over-the-top for your individual applications.

Alumina Powder, methylene chloride, acetone, methanol, do it.

For a more relevant less jerky response, It could leave your source contaminated with hydrocarbons which I have seen interfere with the tuning solution making tuning a nightmare until you re-clean the source

If you use someone's pet recipe for cleaning, you know it works for ever application they carry out on their instrument. It may, however, leave the MSD contaminated with something (particularly components of Jim's Patent Beetle Polish) that happens to interfere with something you decide to measure, if you are unlucky. If you use the manufacturer's recipe for cleaning, you know it's a recipe that works for all their customers. That probably makes it a very reliable recipe, although possibly over-the-top for your individual applications.

Not my pet recipe, it was recommended by the HP engineer who installed our first HP GCMS about 10 years ago. According to a colleague who was there at the time, the engineer suggested he throw away the alumina powder! As far as I know, the method is still used by HP/Agilent engineers (maybe not in the US but certainly in the UK and Ireland).

So far, I've only had one issue with contamination after a source clean (my own fault for trying to take shortcuts). However,as you rightly suggest, just because it works for me does not mean it's the right method for everyone

Yes, when I started in MS ( so long ago I don't want to remember) my HP CE used Wenol polish . They then transitioned to the green paper. Now they recommend the alumina. I was resisting using it due to thhe ease of the green paper. The powder works fine if you rinse, rinse ,and rinse some more. After scrubbing I run hot tap water into the beaker for a while. Then sonicate in 3 each of the following. Tap water, 18 meg water, acetone, methanol. Then bake at <70 ( don't want to oxidize my clean parts). Seems like an excess of rinses but why hurry.

I always clean my sources with a metal polish one knowledgeable field engineer from Agilent (then HP)suggested to me. I always sonicate the cleaned parts with dichloromethane, acetone and methanol. And I must say it works just fine. For what it is worth I recollect seeing some time ago an Agilent presentation on MS tips stating that cleaning with alumina powder was to be avoided. I should say, though, that all Agilent guys that have come to clean my sources recently have tried to con me into using the alumina powder (with no luck so far)

I tend to stick with the alumina powder and the green sand paper, if only because that stuff tends to be available. Its actually somewhat too abrasive, a finer grit is likely better.

I used Wenol for a few years and was quite happy with the nice shiny parts, but I got tired of ensuring the wax was rinsed off.

I have seen people use peanut shells and Comet. Any mild abrasive will do the trick I guess - toothpaste is probably great.

The biggest issue after years of this seems to be cleaning off what ever abrasive you used, and not sanding a divot into your parts .

Most of my colleagues don't seem to get around to telling the new folks that alumina turns black under pressure - I see some kids killing themselves cause the powder never comes off clean.

Any mild abrasive will do the trick I guess - toothpaste is probably great.

I have seen a service technician using toothpaste to clean our 5975C. Wish I could remember the brand...

I always clean my sources with a metal polish one knowledgeable field engineer from Agilent (then HP)suggested to me. I always sonicate the cleaned parts with dichloromethane, acetone and methanol. And I must say it works just fine. For what it is worth I recollect seeing some time ago an Agilent presentation on MS tips stating that cleaning with alumina powder was to be avoided. I should say, though, that all Agilent guys that have come to clean my sources recently have tried to con me into using the alumina powder (with no luck so far)

Jeweler's rouge is also an option (the kind that is synthetic sapphire dust) although I don't see what is wrong with the alumina powder. Make a slurry, keep things moist. You won't scratch anything, and it removes stuff easily. You can also stick a q-tip in a dremel for hard to remove stuff, just again make sure to keep it covered in slurry and moist.

I've cleaned hundreds of sources with alumina powder .

I have heard toothpaste recommended too, LabChick! At least it leaves your source in Mint condition...

Alumina Powder, methylene chloride, acetone, methanol, do it.

Do this. No need to get exotic with your materials. You can even eliminate methylene chloride if you don't need to have it around.

Alumina slurry in methanol or water to scrub then 3 sonicating rinses in solvent with the last one being methanol. No need to oven dry. Blow off parts with canned air if desired then air dry for 10 minutes. Done.