A container is provided for the storage and sampling of aqueous samples, such as deionized water samples. The container comprises an enclosure with an open mouth portion that is sealed via a needle penetratable septa. The septa overlies the mouth and seals the enclosure from the outside atmosphere. The septa comprises a foil layer adjacent the mouth that provides a border between the enclosure and the outside atmosphere and a Teflon layer adjacent the sample. A silicone containing layer of the septa is provided intermediate the foil layer and Teflon layer. A cap member may be provided that is detachably and sealingly engaged to the container covering the mouth. A CO2 adsorbent material may be provided in the space existing between the mouth of the enclosure and a cap member.
