Chromatography Forum

If you read my earlier post about reproducability of headspace blood alc. , it's starting to look as if there is a design flaw with this unit. We changed multiple parameters, rebuilt GC inlet and detector to no avail. No matter what there was a 40-50% drop in areas between our first and second injectios. This pattern repeats if unit is idle for 2 hours. Injections 2-n have good precission for all the compounds.
We gave up and sent our unit back to Tekmar for testing.
We do not accept that we need to run a blank or two before we do anything.

Anyone else seeing this patterd using the HT3?

Thanks
Bear