I use(d) a method of polishing cones after extended use, specially after
samples with high Ca (I do see a deposit on the outside of the cone which is
most likely a CaO layer)
The way I polish:
Take a Dremel or something similar (small held held drill for hobby
purposes), use a wooden toothpick (in the Netherlands we have someting
called a "cocktailprikker" which is a nice round wooden stick with a sharp
point) and while it is turning wind a piece of cottonwool around the tip.
Make a paste of very fine alumina powder and apply on the cottonwool and
carefully start polishing the outside of the cone using almost no pressure:
CHECK CONTINEOUSLY USING A 10-40X MICROSCOPE). When the cottonwool becomes
black, you start start polishing the Ni.
To finish I apply a new stick to the drill, put a drop of past inside the
tip of the cone and gently polish the inside with the wooden tip only.
Then clean with DI-water, and or sonicate for a short while to make sure you
loose all the Al-powder.
Try with an old conew first, (I have been able to boost the sensitivity
polishing the cone, the smoother the surface, the longer it takes to get
Bert (A.A.) van der Hoeff
4902 TT Oosterhout
Phone +31 (0) 162 462 666
Fax +31 (0) 162 462 669
E-mail [log in to unmask]
----- Original Message -----
From: "Adam Subhas" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, January 13, 2010 12:19 AM
Subject: Cone Cleaning (again...)
> Hey all,
> After running a high concentration carbonate sample on our ICP-MS, it has
> come time to clean the cones. I've followed the advice in the previous
> cleaning thread on citranox, and did a 30-minute citranox solution (pH 3)
> sonication followed by a 30-minute DIW sonication. Quite a bit of the
> matrix was removed; however, under the microscope it looks like there is
> still a fair amount of buildup on the sample cone, and noticeable buildup
> the skimmer cone as well. I've heard success stories with EDTA, but am
> wondering about the concentrations - I'm sure EDTA acid would be too
> to use on its own; perhaps a mixture of EDTA acid and the EDTA salt?
> have any experience using EDTA as a cone-cleaning agent? What's a
> pH to shoot for with the mixture? I'm afraid to resort to straight
> acid...Thanks in advance for any advice!
> Adam Subhas
> Research Technician
> Division of Geological and Planetary Sciences
> California Institute of Technology
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