Filter signal with small noise in the base line

hello,

I am looking to detect the different peaks in my signals and as I have to integrate them at the same time i need a smoth signal to detect the begining and end of my different peaks,

I thought about doing first a

findpeak

and then find the begining and the end of the peak by creating a window between each peak possition and then looking at a % of the maximum slope (and a %of the maximun negative) in that peak to find where it begings (and where it ends). my issue is that the signal is a little bit noisy (it is a measurement of GC). A signal threatment it is not my field I am looking some help here. i tryied sgolayfilt and also medfilt1 with no succes...

an immage of the what i see when i use findpeak :

note: I am doing this for positions bigger than 3624 to ignore the first part. so for y(3624:end)

i am uploading the signal fil so it is easier to understand my problem.

thanks