Although the trends in the LSPR shifts imply differences in electron concentration, to assess the number of electrons transferred and discover their spatial distribution within the NCs, we need to analyze the LSPR spectra quantitatively. Specifically, considering changes in the extinction, peak energy, and lineshape during the course of the chemical reduction we can track changes in depletion width and electron concentration in the plasmonic core. In previous reports, 'extra' electrons added by chemical or photochemical reduction have been counted by titrating with an oxidizing agent such as [FeCp * 2] + , but this does not account for the distribution of those electrons within each NC, nor among the ensemble. Polydispersity in the NC diameter and doping percentages, and surface depletion all can significantly affect the LSPR peak energy. Calculating changes in electron concentration while ignoring depletion, in particular, can lead to an underestimation of the electron concentration change due to the assumption that electrons occupy the total volume of the NC. Further, there exists the possibility of oxidized electrons being lost to the very trap states that form the depletion layer, which could hinder the accuracy of this method. To overcome these limitations, we fit the LSPR spectra of our NCs with a recently developed generalization of the Drude model that takes into account heterogeneity in size and doping percentage, as well as surface depletion effects in NCs. The heterogeneous ensemble Drude approximation (HEDA) model takes in fixed input values from experimental data including mean NC radius, NC radius standard deviation, and NC volume fraction in dispersion. The model then fits the LSPR peak for electronic parameters including the electron concentration (ne), standard deviation in the electron concentration (σne), the electron accessible volume fraction (fe) and, the mean free path of the electron (lMFP) (see experimental section for more details on HEDA modeling). While employing spectra from an ensemble measurement, the HEDA model yields a more microscopic view of electron transfer events happening at a single NC level while deconvoluting the effects of heterogeneous peak broadening. Further, this model allows us to track depletion layer charging as a function of added reducing agent by fitting for fe throughout the titration, a critical aspect in correlating depletion layer volume fraction with LSPR modulation. In the development of the HEDA model, results were compared with Mie Scattering theory and physical trends with size and dopant concentration were consistent with expectations for the depletion effects. Given that the HEDA model also determines standard deviation in electron density, it is possible to verify that trends in electron density are not due to wide standard deviation or significant changes in electronic heterogeneity. We expect the HEDA model to be a reliable method for fitting the LSPR of chemically doped samples because the redox agents should modify the electron population in the NCs without substantively changing the fundamental physics governing mean free path, or other parameters built into the model.