No peaks on Agilent Headspace sampler 7697A


I am new to GC work and am having trouble getting peaks. We have the Agilent headspace sampler 7697A connected to the 7890B to measure methane. I was able to get peaks under very specific conditions but now am unable to reproduce these. I’ve tried changing pressures, temperatures, etc settings on both devices to no avail, as well as adding salt to the water solvent in my standards. 

The conditions I was able to observe peaks was strange as well. I could not get any peaks with a gas mixture of methane but I was able to get peaks on multiple occasions with the gas mixture in a vial of saltwater. Both sample types were ran under the same conditions and both started with the similar initial vial pressures. 

I am unsure if there is an internal problem with the machine or if I need to adjust my methods more. Any thoughts/suggestions? 

Thank you, 

Mark Ryan 

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