Integrator Options justyna zakaria  2021-03-15 15:56
 

For certain samples I run, I have extremely long tailing. This is not due to a contaminating peak. Typically I include the whole peak from baseline to baseline (Skyline usually finds this and I don't often need to manually adjust peaks), but in some samples when the tailing takes a very long time to come to baseline this ends up seemingly increasing the noise in the sample. Does Skyline have integrator options like a threshold setting than can be adjusted which is computed from the 2nd derivative which approaches zero as the tail becomes horizontal?
Attached is a photo of such a troublesome sample showing the 3 precursors, but if you look at individual transitions, the same tailing trend is evident across the board.

 
 
Nick Shulman responded:  2021-03-15 20:35
Skyline does not have any sort of options for controlling peak detection.

The peak detection algorithm that Skyline uses first finds the largest peak along the entire chromatogram. Then, based on the width of that largest peak, the algorithm decides how long of a time interval in terms of calculating the second derivative.

When the tail is as small as in your screenshot, the exact placement of the integration boundaries has a very small effect on the peak area. People usually do not worry about where Skyline puts the boundaries in these cases because it has such a small effect on the final numbers.

-- Nick