Seal failure is a mass transfer problem, not a “leak” in the plumbing sense
A 96-vial sequence ran overnight at 4°C. By morning, the first 12 sample positions showed a 7.3% average drop in peak area relative to the calibration check at the end of the run. The solvent was acetonitrile with 0.1% formic acid. The vials were 9 mm screw top with PTFE/silicone septa. Nothing in the audit trail flagged a pressure error, a needle fault, or a temperature excursion. The loss was in the vial, not the instrument. This is autosampler vial seal failure, evaporation and sample lo...
