With the increasing sensitivity of GC's and HPLC's there is an increased need for low bleed septum material to reduce the potential for sample error and to improve overall reliability. The pigmentation in colored septum material can be a source of contaminant and tests show that the ms-PureSeptum is over 60 % cleaner than the standard white/red versions on the market. The ms-Pure Septum is a non-pigmented silicone elastomer of the highest quality characterized by its low bleed, the excellent re-seal ability, it resists coring, is intended for multiple injections, and its low compression makes it suitable for storage reliability.