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injector temperature
Posted: Thu Apr 14, 2005 3:37 pm
by mike
Should my injector be hotter than the maximum column temperature?
Im using a J&W DB 624 column with a maximum usable recommended column temp of 260C, weve been hammering it at 275C for over month now!
Im sure its affecting my results!
Posted: Thu Apr 14, 2005 8:09 pm
by Ron
It is not generally a good idea to heat a column above the maximum temperature for extended periods of time. 275 is pretty hot for that column, but it is a relatively thick phase and will take longer to burn off the phase and get down to bare column, which is a very bad thing in many cases. I would reduce the injector temperature. If you have to exceed the recommended maximum temperature limit to vaporize the compound it probably will not travel through the column well and deposit heavy residues which will affect column performance. I would clip off a foot of the column and lower the injector temperature.
Posted: Thu Apr 14, 2005 9:15 pm
by Answer Man
I agree with Ron. However, if for some reason you need to have your injection port above the column's max temp, you should consider using a short piece of guard column, which typically has a max temp of ~325C.