Chemstation chromatogram scale

[kahmark]

As always, I appreciate your help. Your advice is often helpful, so I appreciate that.

I have a new 7890GC with Chemstation software, as the samples are run, the method and run control output looks wonderful, all the peaks of interest are clearly resolved. However, when I move to data analysis to check integration of those peaks, the y-axis is too large on two of the three signals. Where can I adjust this. Additionally, I'd like to change the minimum peak ht recognized for integration. Where should i look for this and what value should I consider. Our baseline is very clean.

Thanks again!
Kahmark

[QQIB]

Hi Kahmark,

For you first question, you can go to Quant/quantitation report opitions, you should see "Y Axis Scale". If you have a large solvent peak, and let's say that the slovent elutes before 3min, in the window next to "use largest peak after", type 3. then SAVE. You should see your chromatogram has changed.

Hope this helps.

[kahmark]

I think you must use GC/MS, I do not see this option in Chemstation for a standalone GC???? I called Agilent and they were not very helpful (yet). Currently, I have full scale marked which allows me to see two signals clearly but not the third. In this ECD signal, I have a strong air peak followed by a small ppb range N2O peak. I'd like to see this better in the data analysis layout.

Also, I don't use calibration tables per say. I run standards as samples and then use Excel to manipulate the sample concentrations based on a curve build by the std conc vs areas.

[QQIB]

It doesnt matter its GC/MS or standalone, its the software problem. What data analysis software do you use?

I assume you are using the "environmental data analysis" software.

For this software, there are different versions .... I am talking the old version. New version should have this option too..I just dont know where you can find it.....

I would like to post some pictures for you, but not sure how to do it.

[kahmark]

I don't have any add-on software to Chemstation. So, I analyze this data in the offline data analysis mode of Chemstation. The only potential I found so far is in the grahics drop down menu, where I selected full scale for multi signals. This corrected the problem for two signals but not the third. The third signal has a large air peak that the software adjusts to, not the trace gas I wish to show.

I still haven't found the fix yet. Any further ideas? Agilent told me I don't have the quantitation tab in this software.

Thanks again,
Kevin

[QQIB]

No, sorry, that's all I know...

Good luck!

[AICMM]

kahmark,

Under data analysis, report, specify report, should be a button on signal options where you can fix the x-axis printed and the y-axis printed. Not sure how that works for multiple channels (have not worked that way in a while) but if this does not work I will look into it at a local lab I work with.

Best regards.