How the Merlin Microseal Works

A Better Solution to a Complex Problem

A GC injection port septum performs 2 discrete functions. It seals the port while the syringe needle is inserted and during analysis after the needle is removed. The Merlin Microseal is distinct from traditional septa in that the Microseal has two independent sealing mechanisms to perform these functions. A set of O-rings seal the syringe needle during sample injection. A duckbill valve seals the injection port during analysis but allows the needle to slide through it without damage. In contrast, a conventional septum is repeatedly pierced by the syringe needle and eventually leaks or sheds septum particles into the injection port liner. These particles can cause sample adsorption and decomposition and can contribute ghost peaks to a temperature programmed chromatogram.

Microseal Eliminates the Coring and Crumbling of Traditional Silicone Rubber Septa

Because the two seals perform separate, individual functions and are only slightly distorted in operation rather than being pierced, the Microseal septum can be made from a high-temperature, very wear-resistant fluorocarbon elastomer.  In combination with the blunt needle, this means the Microseal septum will not shed pieces into the injection port, even after thousands of injections.

Microseal Step by Step
 Microseal Operation Step-by-Step
  1. Pressure in the injection port, aided by the spring, squeezes the duckbill closed and maintains a tight seal on the port. Higher pressures seal it more tightly.
  2. As the syringe needle enters the Microseal, the wiper rib removes any particles adhering to the needle.
  3. The O-rings of the syringe seal then make a sliding seal around the needle.
  4. As the needle penetrates further, the tip pushes the duckbill valve open and slides into the injection port. The syringe seal maintains the seal around the needle.
  5. After sample injection and as the needle is withdrawn from the Microseal, the spring pushes the duckbill valve closed before the needle leaves the syringe seal. The port remains sealed during the injection process.