PEG contamination in LCQ

[dolphin]

My Mass spec(LCQ) is contaminated with PEG. I have replaced columns,tubing and cleaned the auto sampler. But still the peptide count is low-100, and still seeing PEG. Could anybody suggest a solution for this?

[StevieWonder]

Originally Posted by dolphin

My Mass spec(LCQ) is contaminated with PEG. I have replaced columns,tubing and cleaned the auto sampler. But still the peptide count is low-100, and still seeing PEG. Could anybody suggest a solution for this?

A long washing step with high concentration of ACN? otherwise, think from where it could come... Some new kit used? aceton in eppendorfs? ....

[ylu]

Or if you try to clean the ion transfer capillary? I'm using Thermo Finnigan LCQ Advantage and seems have to clean the ion transfer capillary from time to time as a routine. besides, between the runs of each biological sample, immediate cleaning is important, sometime take time to get the normal background back. I agree, high ACN and MeOH in eppendorfs will bring some high backgr.