GC baseline problem

[wl_yang]

Hi, I run a mixture of alkanes in ethyl acetate in my GC 6890, and found baseline rise after 220 C. I tried the ethyl acetate blank just now and the same. I haven't used this instrument since last Dec and it was fine untill the last run for pesticide in hexane.

What is wrong with my GC? Inlet or column problem? Also, see three big peaks of cyclosiloxane.... at low temperature.

Thanks!

[along]

When is your last change of GC Column, may be you can flush your column for sometime before you injecting again.

[shalash]

Hi, I run a mixture of alkanes in ethyl acetate in my GC 6890, and found baseline rise after 220 C. I tried the ethyl acetate blank just now and the same. I haven't used this instrument since last Dec and it was fine untill the last run for pesticide in hexane.

What is wrong with my GC? Inlet or column problem? Also, see three big peaks of cyclosiloxane.... at low temperature.

Thanks!

hi
im shalash

i think you have to conditioning the column for 16 hr with out connect to detector then i think u can have good base line