This work centers on an evaluation of the impact of photo-oxidation of the porous Si (PS) surface on the ability of the triaryl derivatives of the Group 15 elements EPh(3) (E = N, P, As) to quench the photoluminescence of porous silicon. The ability of porous Si to be quenched by these Group 15 triaryl derivatives is monitored with regard to four different surface treatments : freshly prepared porous Si, (i) without and (ii) with illumination to steady-state photoluminescence intensity; porous Si aged in ambient air for one month, (iii) without and (iv) with illumination to steady-state PL conditions. We specifically employ as a criterion for such an analysis the magnitude(s) of the maximum percentage of the integrated PL which can be quenched by a given Lewis base for a particular surface, and compare the trends observed with reported gas phase proton affinities.