Short thread polypropylene caps fit short thread vials. Caps are available in different colors, septum materials, and open or closed configurations to suit your application. UltraBond cap and septum form a one-piece unit using a bonding process without adhesives for contamination-free results. Pre-slit septa prevent vacuum forming inside the vial.

All MS applications require extremely clean vials and closures, as this method of analysis is very sensitive to any kind of contamination. Therefore it is common to only use Silicone/PTFE septa in this field of chromatography as the purest available liner material. However, most end users still experience problems with even the highest grades of Silicone/PTFE septa due to ghost peaks arising from volatile siloxanes. Various treatments of the septa can reduce the level of these volatiles, but not eliminate the basic problem. The MS Cap was therefore developed as a one component 9mm Short Thread Cap that doesn’t require a septa. This cap is inert and shows a similar chemical resistance to PTFE. Thus it can be used for sealing vials with all kinds of samples without loosing inertness. Furthermore the cap is made out of a special material that is pierceable with all common types of HPLC and GC needles, as it has a thinned penetration area with a diaphragm. Although it has no septa, evaporation tests have shown that it is liquid- and gas-tight. Each manufactured batch is LC/MS and GC/MS controlled and supplied with an appropriate certificate. The certificate states instrument, column and other method conditions being used for the test.