Septa

Even when a low bleed septum is used, bleeding is not totally eliminated. The type of bleeding differs according to the septum type and bleeding appears as different peaks on a chromatogram. In high-sensitivity analysis, you need to select and use a septum that does not cause bleeding at a position where interference occurs with the target compound.

When using an autosampler, it is recommended to exchange the septum after about 100 injections. If the injection is done manually or the outer diameter of the needle is thick, the septa should be replaced more often.