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Sensitivity Help - Chrozen Clarity

Posted: Sun Jan 22, 2023 2:02 am
by labjohnstown
I am setting up USP testing for Ethanol samples.

I have a great method developed and I can pick all of the peaks up. My issue is when I get to under 5ppm, I can see a very small rider peak where my acetone should be but i cannot integrate it.

I have played with a bunch of physical parameters on the gC but the peak seems to remain in the same condition.

I am looking now to play with the HRz but I put it up to 500 and it will not seem to help with the peak shape.

I am not sure what Sensitivity is at all or how to use it, and I am also not 100% sure about what the best settings for range are.

Is there anything else that I could do in the software to help improve the ability to pick up those very small peaks?

Thank you

Re: Sensitivity Help - Chrozen Clarity

Posted: Sun Jan 22, 2023 6:13 pm
Did you try to play around with the (Global Threshold) or (Global Peak Width)? this sometimes come in handy to make very small peaks detectable but if the chromatogram is noisy, you may find many unwanted small integrated peaks.
You can find this in (Method)-> (Integration) tab-> Select your desired detector if more than one is available, then reduce these values gradually and try each time.

Re: Sensitivity Help - Chrozen Clarity

Posted: Sun Jan 22, 2023 6:29 pm
by labjohnstown
I have tried to integrate the peak. I am going to attach a photo of the peak to show. I am very good normally at getting small peaks but it is riding on the tail of the solvent peak.

even when I use tail tangent and the lowest of the threshold and peak width is will not grab it. This is why I'm trying to get the peak to come out a little more by adjusting parameters on the GC. I am just not sure in the acquisition tab what some of the parameters refer to and there are no definitions in the help. I am trying to find out what the Sensitivity does as well at the Range. I'm not sure if it helps to zone in on peaks more. I do know how to change the sample rate and have optimized that.

Re: Sensitivity Help - Chrozen Clarity

Posted: Mon Jan 23, 2023 8:25 pm
An approach is to try to add this as a peak by selecting (Add Positive) then mark its start and end, then try the tail tangent.