I have my raw data and a basic processing method develop by someone who is not longer in the lab. When I am checking my standard for serotonin and dopamine, the RT from the basic method changed and now I see two peaks with the mass I am looking for, how do I choose?

Also in serotonin/Serotonin D4 the spectrum plot:
doesnt show me the mass I am looking for
it is but there are more mass peaks
it seems cut off

What can I do to verify the peaks? because right now the calibration curve it is a mess