broken SPME fiber

[mezek]

what are the possible reasons for breaking the SPME fiber?

[Schmitty]

Typically, I will break them if I am working too fast and forget to retract the fiber before pulling the assembly back through a septa.

Also, forgetting to retract the fiber BEFORE going through the septa is a sure-fire way to wreck it

At what point are you noticing that your fibers are not the original length? Is the coating cracking off the substraight, or is the whole substraight missing?

[Thunderbunny]

You should be using pre-drilled septa or preferably a microseal with SPME. Using normal septa will damage the fibres.

[Radish]

Regular (non-pre-drilled) septa will not damage a spme fiber unless you forget to retract it before insertion or removal as Schmitty has pointed out. I have used both types of septa for thousands of spme injections with no problems.

I have in the past received fibers with cracked coating from the supplier (Supelco). This does not seem to affect the performance of the fiber, but I think it is more likely for some of the coating to slide off the support in this condition should you inadvertantly bump the fiber. For example, the fiber might touch the side of the inlet liner as you are exposing it.