Chromatography Forum

Hello,

My Name is Craig Quackenbush, I am new to the Forum, so please bare with me if this has been covered before.

At my company we run HP 5890 and 6890 GC's, but we use Totalchrom as our chromatographic data system. For the most part this works fine, but we can not seem to run the GC's in splittless mode. I was told by our IT group that the only way to do this was to set a timed event for the split valve at time=0.00min. Unfortunatley the instrument configuration in Totalchrom seems to be set up wrong, and the timed event effects absolutly nothing.

So my questions are; Is there a way to set up the 6890 in true splittless mode using Totalchrom; Or how do I configure the valves so I can at least us timed events to close the split vent?

Craig

Have you tried a timed event at a time other than 0.00 ? Not familiar with the Totalchom software nor control of a 6890 by timed events however for Splitless you must set a time in the splitless control on the GC. If your data system does not control this parameter could you set the splitless time to 1 minute or does the downloaded method over ride it ? Timed events usually need both an on and an off command. If the data system sends a "splitless" on command to set the GC to Splitless this may need to be at the end of the previous method. Most data system will not accept a timed event at 0.00 seconds only at 0.01 seconds. Does the data system drive the GC or the GC start the data system ? If the latter, 0.01 seconds will be after injection and will not work. You would in either case need to reset your timed event to open the split valve at the end of the splitless time and to prepare the GC for the next run.
Hope this helps

Thanks for the reply. I have tried timed events other than 0.00min, and the instrument will not respond to any timed events, and that leads me to believe that it may be configured wrong, but I am not sure what config change to make or if anything can be done at all. The instrument is controlled by the software, (But not very well in my opinion). I am stuck with Totalchrom software, and Agilent hardware. I know PerkinElmer says it is compatible, but I am beginning to wonder what level of compatibility they are talking about.

Craig