what is the most common reasons for clogging of ESI probe

[jiangds06]

i am running a LC-MS instrument. One day ESI capillary got clogged. I just wonder LC column should be very good filter for these particles. why LC column did not stop these particles?

[lmh]

anything that is soluble can get through the column; anything that is not volatile will dry out in the spray chamber and may block either the capillary linking the spray chamber to the vacuum part of the instrument, or occasionally the spray needle.

The usual suspects are salty buffers in the solvents, but repeated injections of concentrated samples can do the same thing.

[MMJ88]

Seconding what lmh said. It's probably a salt in your solvents. I have encountered this on my instrument.

[jiangds06]

But i do not salt in my buffer. only volatile buffer.

Seconding what lmh said. It's probably a salt in your solvents. I have encountered this on my instrument.