Approximately 5 mL of H2SO4-SO3 was drawn into the plug before emerging from the top of the plug. This was repeated 3 times, dry nitrogen was blown through the plug, and the plug was rinsed repeatedly with dichloromethane or 1,2-dichloroethane. With conventional ABS filament, the functionalized ABS plug (ABS-SO3H) was not compatible alcohols or acetone.