When required
When, during APCI operation, you observe decrease sensitivity, decreased signal stability, and increase corona voltage.
Tools required
Abrasive paper, 8000 grit, 8660-0852
Cloths, Clean, lint-free, 05980-60051
Gloves, clean
Isopropanol, reagent grade or better
Parts required
None

  1. Pull the corona needle assembly out of the spray chamber.
  2. The needle and related parts get very hot during operation. Make sure they have cooled before proceeding.
  3. Fold a piece of abrasive paper over the base of the needle.
  4. Pull and twist the abrasive paper along the needle and off the tip of the needle.
  5. Do not bend or blunt the tip of the needle; it will decrease system performance. Sharpening the needle is not necessary.
  6. Repeat steps 2 and 3 several times.
  7. Starting at the base of the needle, wipe the needle with a clean cloth. The cloth can be dry or dampened with isopropanol.
  8. Reinstall the corona needle assembly in the spray chamber.
  9. Do not hit the tip of the needle against anything. It will bend the tip which will decrease system performance.
  10. If this procedure fails to restore system performance, replace the corona needle.