Hello, we are using a 7693 autosampler and 7890B GC/MS with MassHunter 10.2.489 acquisition software. When running a batch some vials do not collect as expected. We only get a baseline through the injection. If the same vial is re-injected the expected chromatography is captured. This is very random... sometimes only one or two out of a batch of 30. Thank you for any input.