I recently removed the cones on our 7900 ICP-MS for maintenance, and saw that the skimmer base seems to be seriously corroded (see picture). There is no apparent effect on the performance of the instrument, but since it has been shut down for a long time, it is hard to make a direct comparison. And visually it looks like it could be a problem.
We have also been puzzled by the cause of the corrosion. Since it has previously been connected to a LC, our theory is that there has been a solvent flow on while the plasma was turned off, which led to accumulation of solvent in the interface region. This is also supported by traces of drips from the sampler cone (not in the picture). However, I have not heard of any other experiences with similar problems.
Do you have any suggestions
1) As to what can have caused the corrosion?
2) Whether it will pose a problem for instrument performance?