Sinusoidal baseline.

Hi ccbarnes5,

I have updated the tags for better visibility. Have you tried a new jet in the FID? It could be restricted with carbon. Also when you reply, it would be helpful if you could reply with your method parameters .

Regards

James

Oops.  The HS conditions are:

Curtis [Personal information removed by moderator]

At first glance I don't see much to be concerned about here with method parameters other than the gas saver flow is 15ml/min, 5ml below the suggested of 20ml/min. Has there been any maintenance done to the FID, jet change etc?

James

No.  There has NOT been any change with the detector; yet.  We’re going to try changing the FID.  I’ll take a look at the collector when the jet is changed.  The issue that’s really throwing us off is that it only happens AFTER the elution of the solvent (Dimethyl acetamide), when the oven temperature gets over 160°C.  AND it’s so consistent.  Subsequent chromatograms can be overlaid and that baseline will look EXACTLY the same over that time period (about 15.5 minutes – 20.0 minutes).

Curtis [Personal information removed by moderator.]

No.  There has NOT been any change with the detector; yet.  We’re going to try changing the FID.  I’ll take a look at the collector when the jet is changed.  The issue that’s really throwing us off is that it only happens AFTER the elution of the solvent (Dimethyl acetamide), when the oven temperature gets over 160°C.  AND it’s so consistent.  Subsequent chromatograms can be overlaid and that baseline will look EXACTLY the same over that time period (about 15.5 minutes – 20.0 minutes).

Curtis [Personal information removed by moderator.]