Caps, Screw Top, with Red Rubber / Mylar Septa, fitted in "knurled", polypropylene, Blue Caps. For use with 9-425mm thread, 12x32mm autosampler vials. BASIK Brand. 100/PK.
Additional Info:
The 9502S‑E‑40C‑B screw caps are a specialty yet economical autosampler cap option, utilizing a red rubber septa laminated with Mylar rather than PTFE. This construction offers unique mechanical and chemical properties that are well suited for specific routine chromatography applications.
Unique Septa Construction and Benefits
Red rubber core provides excellent elasticity and resealing characteristics, allowing the septa to recover quickly after needle penetration.
Mylar facing acts as a chemical‑resistant barrier, protecting the rubber from swelling or degradation while improving durability during repeated injections.
The Mylar layer also offers enhanced needle wiping, helping remove residue from the needle exterior as it penetrates the septa—an advantage in applications where instrument washing steps are limited.
Typical Uses and Applications
These caps are commonly used in routine HPLC and GC workflows where:
Ultra‑low extractables or LC‑MS cleanliness is not required
Mechanical durability and resealing are more important than maximum chemical inertness
Cost efficiency is a priority
They are particularly well suited for:
Method development and training labs
Quality control laboratories
General‑purpose GC and HPLC assays
Applications using robust solvents where PTFE‑level inertness is unnecessary
Cap Design and Handling
The knurled polypropylene cap body allows secure gripping and consistent torque application, reducing the risk of overtightening or slippage during manual capping. The fitted septa design provides reliable performance for standard autosampler injection forces.
The 9502S‑E‑40C‑B caps offer a practical balance of performance, durability, and economy, making them a valuable option in laboratories that do not require PTFE‑based septa but still demand dependable autosampler sealing.