Hi everyone!

I am currently working on extracting quinolines from textile samples but I experience a complete lack of reproducibility when it comes to the ATD injection.

I am basically cutting out a small piece of textile and putting it in the steel tube, plugged with a metal insert to prevent it from leaving the tube. Then this is thermally desorbed but even though I run with the same parameters for different samples, I get completely different results.

These parameters gave good results before, with nice peaks from the quinolines:

Desorb temp: 180 deg
Desorb flow: 60 ml/min
Desorb time: 5 min
Purge time: 1 min
Trap low: -10
Trap high: 300
Trap hold: 10 min
T-line temp 240
Valve temp: 220
Inlet split: 0
Outlet split: 0 ml/min
Flow: 1.6 ml/min

However, when the same parameters are run again, the next chromatogram looks like a blank. It makes no sense.

I tried to inject a standard solution of quinolines (40 ng/ul), by spiking 1 ul on glass wool in a tube. This resulted in no peaks in the chromatogram.

What do you think is the problem? The cold trap looks a bit.. frayed and it has ice on it - indicating maybe a leakage?

Please help! :)