Small injection volumes, non-linear results

Applies to

Autosampler AS 100/110

Summary

Decreasing the injection volume results in non-linear behavior.

Cause

Leakage over the valve rotor seal results in loss of sample. Especially when using partial loop fill for small sample volumes this will result in unexpected loss of signal.

Diagnosis

Although difficult to see, droplets may be visible coming out of the sampling needle in resting position. Injecting small samples (1-2 µL) with partial loopfill does result in unexpected loss of signal.

Remedy

Replace valve rotor seal. Read how in AS 100/110 user manual (document 181_0010 or 191_0010).