When coupled to a time-of-flight (TOF) mass analyzer which provides a high transmission, quasi-simultaneous detection of secondary ions, and theoretically unlimited mass range, secondary ion mass spectrometry (SIMS) is well suited for submonolayer molecular analysis of solid surfaces. Additionally, molecular ion images may be obtained by using a focused primary ion beam rastered on the sample surface to provide lateral distributions of chemical species.TOF-SIMS has been shown effective at characterizing low level polymer additives such as UV absorbers, thermal stabilizers, anti-oxidants, and slip agents in polymer extracts deposited on roughened Ag substrates. Additionally, in-situ analysis of linear low density polyethylene (LLDPE) samples using TOF-SIMS has provided information on surface segregation and surface oxidation. The polymer extract analysis has the advantage of both preconcentrating the polymer additives, as well as providing enhanced ion yields through Ag canonization. However, the in-situ analysis is also a valuable approach since it alleviates the time consuming extraction procedure and provides information on additive surface segregation and oxidation.