This work reexamines fundamental issues for the implementation of total internal reflectance fluorescence (TIRF) in quantitative studies of polymer adsorption : the utility of internal calibrations for surface excess and complications stemming from light scattering, chain labeling topography, and quantum yield changes on adsorption. Scattered photons were found to have a greater impact on the signal than documented in the literature, motivating the development of an improved universal calibration. The work then probes the history dependence of TIRF-obtained isotherms for poly(ethylene oxide) (PEO) and (hydroxyethyl)cellulose (HEC) on silica, comparing coverages to those on silica particles. With sufficient equilibration time, the TIRF-obtained isotherm shapes for PEO approached those on silica particles, suggesting linearity of TIRF signal in interfacial chain number. Also apparent for PEO (1 label/chain) was the surface selectivity for high molecular weight populations, which artificially lowered the apparent mass coverage by up to a factor of 2. TIRF-obtained isotherms for HEC were strongly history dependent in a manner that suggested solvent-induced interfacial relaxations and a sensitivity of fluorescein quantum yield to HEC chain configurations.