This Information Applies To: Agilent 6000 Series LC/MS systems.
Efficient electrospray ionization (ESI) in your LC/MS ion source requires a properly adjusted nebulizer needle in good condition. The nebulizer needle is a consumable item in your ion source that may need to be replaced when the following signs are observed:
This article describes how to replace the nebulizer needle in the ion source of your Agilent LC/MS system.
Steps to follow
Put on clean powder free nitrile gloves
Determine the nebulizer holder type by comparing your nebulizer to Figure 1.
Caution: When inserting the nebulizer into the nebulizer adjustment fixture, ensure that the nebulizer tip does not contact the fixture, or the nebulizer needle tip may be damaged.
Mount the nebulizer assembly into the nebulizer adjustment fixture as shown in Figure 2.
Slide the heads of the two spring loaded socket head cap screws through the mounting holes of the nebulizer.
Twist the nebulizer clockwise to hold the nebulizer assembly firmly in the fixture.
Gently tighten these screws further to hold the nebulizer firmly in the holder.
Loosen the locknut next to the zero-dead-volume (ZDV) union and then remove the union from the nebulizer needle holder, as show in Figure 3.
Remove the union locknut from the nebulizer.
Loosen the fastener (locknut, 1.5 mm hex screw, or T6 Torx screw that secures the needle holder in place. (See Figure 1)
Loosen the needle holder and pull it out of the nebulizer body.
Dispose of the used needle safely according to your laboratory disposal protocols. See Figure 4.
For a more thorough cleaning, remove the nebulizer body from the adjustment fixture block, then sonicate the nebulizer body in LC/MS-grade isopropanol (IPA) or methanol for a least 15 minutes.
You can also pour the cleaning solvent through inside the nebulizer shaft.
Dry the nebulizer body completely and then reinstall on the adjustment fixture block.
Caution: Do not bend the needle in the next steps as you slide the needle into the ferrule. The needle is fragile, and a bent needle results in poor alignment with the nebulizer body.
Carefully remove the new needle from the shipping tube and identify the sharp and blunt end of the needle. See Figure 5.
Slide the blunt end of the needle through the needle holder and into a new black ferrule until 1 cm of the blunt end of the needle sticks out of the ferrule. Then push the needle back into the needle holder until the blunt end of the needle is flush with the end of the ferrule. See Figure 5 for more detail.
Reinstall the locknut and the union, then hand tighten the union onto the end of the needle holder.
Hold the needle holder steady on a clean surface with either a 3 mm open-end wrench or 1/4-inch x 5/16-inch open-end wrench (depends on your nebulizer holder style),
Tighten the union 1/2 to 3/4 of a turn, or until an audible squeak is heard. The ferrule is now compressed onto the needle, see Figure 6.
With clean gloves, pull carefully on the needle to ensure that the needle is held firmly in place by the compressed ferrule.
Take care of the sharp end of the needle when performing this check.
Insert the needle and needle holder into the nebulizer body and turn the needle holder to engage the thread in the nebulizer body, see Figure 7.
Adjust the new nebulizer needle to the correct position by following these instructions: How to Check and Adjust the Nebulizer Needle on Agilent LC/MS Systems
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