The sealing property of the headspace vial is better than that of the threaded vial, and the rubber or silica gel has good re-sealing after the puncture, so it is ideal to preserve the reagents. If some of the organic solvents in use will corrode the silicone or rubber bottle pad, the bottle pad with PTFE coating is required, if in use, the reagent is not used up once, but stay in the headspace...