Detector Response(Empower/OpenLab)

Basic questions from students; resources for projects and reports.

6 posts Page 1 of 1
Hello,

Recently I had a problem with the detector response, in the company where I work, we usually operate Empower and OpenLab, but the parameters on the response are different, while in Empower the unit is points / sec in OpenLab it is peakwidht minimum/Hz. My question is how can I optimize this parameter for my peak (in some cases I realized that in given response time my peak had 1200 of theoretical plates and just changing that value rose to 3000) and how can I relate the units of the two systems to not have problems in methodologies developed in different software / equipment?

Excuse my English, I'm Brazilian and I'm still studying the language. Thank you.
Hello.
Plates number depends on peak time and width not on response… Of course instrument, mobile and stationary phases etc influence on plates number.
Best regards,
Dmitriy Perlow
as a rule of thumb collect at least 20 data points across a single, well resolved peak.
So if your peak width (@baseline) is 10 sec, your data rate should be at least 2 Hz (points/sec).

If you have peaks which are not baseline separated, the data rate should be increased.
Some oversampling usually doesn't hurt, nowadays, the PC storage space often isn't too limited. So I would go for >50 points per peak in complex mixtures.

Also make sure, not to have some wrong data filtering (smoothing) conditions set in the instrument method of your detector.

Best way to learn about your systems and software is to try different settings as you already did. Test other data rates as well. After some point, your plate count should stay +/- constant.
In Empower there is also a field called "points across peak" (normally it's hidden), which shows you how many data points were collected over a certain peak.
Hollow wrote:
Hello.
Plates number depends on peak time and width not on response… Of course instrument, mobile and stationary phases etc influence on plates number.


Yes, you are right but the detector response is very important too, because this parameter, when used improperly, can cause the peaks to widen and sometimes until they are not detected.

Hollow wrote:
as a rule of thumb collect at least 20 data points across a single, well resolved peak.
So if your peak width (@baseline) is 10 sec, your data rate should be at least 2 Hz (points/sec).

If you have peaks which are not baseline separated, the data rate should be increased.
Some oversampling usually doesn't hurt, nowadays, the PC storage space often isn't too limited. So I would go for >50 points per peak in complex mixtures.

Also make sure, not to have some wrong data filtering (smoothing) conditions set in the instrument method of your detector.

Best way to learn about your systems and software is to try different settings as you already did. Test other data rates as well. After some point, your plate count should stay +/- constant.
In Empower there is also a field called "points across peak" (normally it's hidden), which shows you how many data points were collected over a certain peak.



Hey, you helped a lot, I researched the term "points across peak" on google and found articles on the Agilent and Waters detector response, now I'm reading and understanding much more clearly, including in the Agilent article they describe which you wrote here, very cool.

Thank you all for the answers.
Sorry…
Best regards,
Dmitriy Perlow
dap wrote:
Sorry…

No problem, until recently I didnt know either. But the forum is important for this. I really appreciate your answer.

Thank you.
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