I have been using MALDI-TOF to calculate the proportions of different polymers from my polymerisation. I am having difficulties trying to confirm the mass of the end groups using the relationship of Mi = Mmon*n + (Meg + Mna+)
by plotting the molecular mono isotropic mass v's degree of polymerisation. Degree of pol calculated by dividing the mono isotropic mass by the mass of the monomer unit. However when I perform the linear regression, my regression line passes pretty much through the origin and my Y-intercept (end group mass + cation mass) is a very tiny number i.e. 625E-06, when it should be around 127.
My only idea why this is going wrong is because the end group mass is bigger than monomer mass and as a result when I try and work out he degree of polymerisation it is one higher than it should be.
Also after I ran the MALDI i smoothed the results? would this effect the results?
Any help is appreciated