DualSeal (Double Cap) Sealability Test: Moisture Analysis

In order to evaluate the sealability of DualSeal, we periodically measure and monitor the moisture increment by Karl Fischer method after piercing the septum of 500 mL bottle by a needle.

Measurement condition

500 mL anhydrous tetrahydrofuran (TCI product number: T2394) was compared with competitor’s 500 mL anhydrous tetrahydrofuran.
The septum moiety was pierced using a 18 gauge needle at 4 different positions every week (total 20 different positions pierced in 5 weeks).
After piercing, the sample solvent was taken and the water content was measured by Karl Fischer method.
After sampling, the septum was sealed by an over-cap with 1.5 Nm torque and the sealed bottle was stored in a closed environment at ca. 24 ℃, ca. 75 % RH.

Periodical measurement to monitor moisture increment every week (totally 5 weeks) showed a remarkable difference in the water content (in ppm) between TCI and the competitor’s samples. This result indicates that the PTFE sheet inside the over-cap can tightly seal the septum and the over cap.

Eventually use of the DualSeal can maintain the quality of product in sealed bottle for a long time.

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