In the present study, a reliable and robust method was developed to quantify the molecular weight discrimination that can occur in grafting to reactions via indirect MALDI-TOF quantification of the molecular weights of grafted chains by comparing the characteristics of the polymeric material before the grafting reaction with those of the unreacted material recovered after grafting. Two polystyrene samples with different molecular weights and narrow molecular weight distributions were employed to prepare model blends that were grafted to silicon wafers and an analytical method was developed and validated to assess and quantify the modification of the molecular weight distribution that takes place during the grafting to process. Particular attention was paid to the standardization of the sample treatment and to find the best data collection and calibration methodologies in order to have statistically significant data even …