IMPLEMENTED - Peak Identification Option in Time Windows

[stuart]

It would be really useful to be able to identify peaks in time windows with the option of choosing the first peak in the window, the biggest peak in the window or the nearest to the retention time.

Internal issue tracking ID: 30184

[Ivan Vins]

In Clarity the ordinary peaks are identified as the closest to the expected RT, while the reference peaks are identified as the biggest peak (referred to area or height selected for quantification) in its identification window. The request to detect the first peak is rather uncommon - some reason for it?

[stuart]

Identifying peaks by "Closes to Retention time" only works if you have narrow windos and rock solid retention times. If the lab temperature changes (and hence the eluent temperature changes, so do retention times, from one day to the next. If a user makes up frsh eluent every day, there will be some (hopefully small) variations. The solution is to open up the windows a bit and identify as the "biggest peak". Customers using some other data systems are used to this and expect it. Selecting the "first peak" is less commonly requested, but still useful. For example if the peak is the first in a group, we really don't want to get the next one just because it is nearer to the RT sometimes.

Not everyone will want these options, although some people feel very uncompfortable when they find it isn't there. Not many of our customers use the reference peak option, yet that is almost the only way to be sure not to get incorrect peak ID if the only option aavailable is " Closest to RT". The danger with relying on a reference peak is that the peak areas can change with retention time, so if a customer sets the reference peak window too wide, it finds the peaks but gives the wrong results.

I don't know how hard it would be to add this function. but in my experience, if a customer asks for it, we don't get the sale.

[Ivan Vins]

I am not really understanding your last comment about reference peak and wrong areas - in fact I do not see any difference to the required Identify by biggest peak option and existing Reference peak type behaviour in respect to peak identification. The difference is, that the identification windows for ordinary peaks will be shifted according to the found reference peaks. If you will set all peaks as Reference, the behaviour will be exactly the same.

[Daniel Mentlik]

The issue was implemented in Clarity version 3.0.2.244