This Information Applies To: Agilent 6000 series LC/MS instruments
Cleaning the ion transfer capillary as part of regular maintenance or as part of troubleshooting when a loss of sensitivity in the instrument occurs.
Steps to follow
Cleaning the ion capillary is a part of regular maintenance of your LC/MS instrument and can also help to regain instrument sensitivity. There are two recommended methods for cleaning the ion capillary.
Either one of these methods can be used to clean the ion capillary depending on the equipment and materials available.
Caution: To maintain proper cleanliness, always handle the ion transport capillaries with clean gloves.
1. Put on clean gloves.
2. Dissolve 1 g of Alconox cleaner in 100 mL of de-ionized (18 MΩ-cm) water. This is the recommended concentration for both syringe and ultrasonic cleaning.
3. Cut a small length (approx. 15-20cm) of the flexible tubing and insert the syringe adapter into one side of the tubing.
4. Carefully slide the capillary into the other end of the flexible tubing. See Figure 1.
Figure 1: Inserting tubing and syringe adapter onto the ion capillary
5. Fill the syringe with an Alconox cleaning solution and connect the syringe to the syringe adapter.
Caution: In the next steps, hold the capillary securely to prevent ion capillary damage. Also take care not to push the syringe plunger too hard to avoid forcing the tubing off the syringe adapter or capillary, especially if the capillary is partially or fully blocked.
6. Hold the outlet of the ion capillary over a waste container and use the syringe to push 20 mL of cleaning solution through the capillary. See Figure 2.
Figure 2: Pushing Alconox cleaning solution through the syringe with a syringe connected to the syringe adapter
7. Repeat this process at least three times using MillQ (18 MΩ-cm) or LC/MS-grade water until the ion capillary is thoroughly rinsed. It is important that all cleaning solution is rinsed from the capillary to allow for efficient ion transmission.
8. Remove the tubing from the capillary and blow out excess water from the ion transport capillary bore using an air sprayer or oil-free pressurized gas.
9. Record this procedure in the Maintenance Logbook.
1. Cut the tips off two 1 mL micropipette tips and place one on each end of the ion capillary. The micropipette tips will protect the delicate ends of the ion capillary during sonication, see Figure 3. If the appropriate sized clean polypropylene graduated cylinders are available, then this step can be skipped. The polypropylene cylinders will not damage the delicate metal plated ends of the ion capillary.
Figure 3: Cut pipette tips on each end of the ion capillary.
2. Carefully place the ion capillary in the clean graduated cylinder and fill the cylinder with Alconox cleaning solution. See Figure 4.
Figure 4: Fill the cylinder with Alconox solution so the capillary is completely covered.
Warning: Sonication of the ion capillary should be done under a fume hood or other suitable extraction device.
3. Sonicate the graduated cylinder containing the capillary for 10–15 mins. Do not sonicate for more than 15 mins as this can risk damaging the metal coating of the capillary ends.
4. Remove the ion transport capillary and rinse both the cylinder and the capillary several times with de-ionized (18 MΩ-cm) water.
5. Repeat this ultrasonic cleaning step a minimum of three times using de-ionized (18 MΩ-cm) water in the graduated cylinder. It is important that all cleaning solution is removed from the capillary to allow for efficient ion transmission.
6. Remove the cut pipette tips from each end of the capillary and blow out excess water from the ion transport capillary bore using an air sprayer or oil-free pressurized gas.
7. Record this procedure in the Maintenance Logbook.
Learn Essential Housekeeping Tasks and Best Practices for Agilent 6400 Series LC/TQ
LCMS-6400-1201s - Essential Housekeeping Tasks and Best Practices for Agilent 6400 Series LC/TQ e-learning course available from Agilent Education