If the baseline is noisy (> 3 nS with hydroxide or MSA eluents, > 10 nS with borate eluents, > 7 nS with carbonate or carbonate/bicarbonate eluents and the Dionex ADRS 600 or Dionex AERS 500e, > 2 nS with carbonate or carbonate/bicarbonate eluents and the Dionex AERS 500 Carbonate), it could be caused by trapped air bubbles in the cell or tubing.

Procedure

  1. Burp or release the trapped bubbles by gently tapping on the cell while the fittings are slightly loosened or bleeding the tubing.

In the following figure, a bubble is released from ELUENT IN line by loosening and tightening the fitting at 56.6 minutes into the run.

Noise:

  • ~2.5 nS before
  • < 0.5 nS after
Effect of Air Bubbles on Baseline Dionex ADRS 600 (4 mm), Recycle Eluent Mode
Effect of Air Bubbles on Baseline Dionex ADRS 600 (4 mm), Recycle Eluent Mode