New inlet, same method, poor phenol chromatography
Posted: Thu Nov 26, 2009 9:24 pm
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I have just installed a JAS UNIS programmable PTV inlet. I ran a hot splitless PAH/Phenol method that was identical to the one we have been running on the old agilent inlet and my phenols have gone nuts (some are splitting, all are tailing/smearing and some have disappeared altogether).
I suspect it is a liner issue as the column has been clipped and is fairly new, (although it was starting to lose phenol performance, it was not as bad as it is now) . I have tried multiple methods of cleaning the liners and tried different glass wool configurations to no avail.
Would you expect a method like this to be transferable between different inlets or are there some parameters (e.g. start temp) that are specific to the inlet?
A brief summary of the method;
6890/5973
inlet temp 280c constant
splitless with 50ml split purge after 1 min, 20ml/min gas saver after 5min
col flow 1.2 (constant pressure)
DB5.625 column with de-activated silica pre-column, quartz column connector
de-activated glass liner, tapered splitless end, de-activated glass wool in situ
oven start temp 60c (can't remember ramp - I will check tomorrow)
injection speed 'fast' (agilent default)
2ul injection
sample: 50% DCM extract/50%toluene PAHs/phenols at 2ng/ul
Before this I tried pulsed splitless, 1ul injection, and 90%DCM extract/10%toluene with no luck
any ideas?