Replacing and Adjusting the Agilent ICP-MS System Peristaltic Pump Tubing

Answer

This Information Applies To: Agilent ICP-MS 7700, 7800, 7850, 7900, 8800, and 8900 systems

Issue

Peristaltic pump tubing that has lost its elasticity will not deliver the sample to the nebulizer correctly. When the pump tubing appears limp or flattened or does not require stretching to fit over the pump rollers, it should be replaced with new pump tubing.

Background

Agilent pump tubing, PVC tubing and connector barb sizes vary with application. Some sized tubing will not require a connector barb. Always ensure that the drain tubing has a greater internal diameter than the sample tubing.

To reduce the dead volume and maximize sample throughput, cut and remove excess pump and PVC tubing. Leave at least 10 mm outside the tags on ends of the pump tubing.

Use the Agilent tubing cutter (p/n 8710-1930) for a clean cut with no damage to the tubing end. Damage may cause flow rate problems. 

Figure 1. Peristaltic Pump Components
1. Sample uptake tubing, 2. Internal standard uptake tubing, 3. Waste uptake tubing for drain, 4. Knob to adjust the clamp tension, 5. Clamps, 6. Spray chamber drain tubing, 7. To nebulizer, 8. To drain vessel.

Warning: The peristaltic pump has moving parts that can damage hands or fingers caught underneath the clamps during operation. Keep hands away from the peristaltic pump while it is rotating.

Steps to Follow

1. Installing the drain tubing

1. Check the direction of rotation as indicated by the arrow on the peri-pump
2. Note the installed position of the tubings.
   • Drain tubing is on the right, sample tubing is on the left, and internal standard tubing is in the middle.
3. Hang the downstream drain tubing stopper over the top of the peri-pump.
4. Stretch the tubing over the rollers and hang the upstream stopper underneath the peri-pump
5. Recheck the direction of the peri-pump rotation and confirm that the drain flows toward the drain vessel
6. Clamp the tubing by engaging the adjustment arms

Figure 2. Installing the drain tubing

2. Installing the internal standard tubing

1. Hang the downstream internal standard tubing stopper over the top of the peri-pump.
2. Stretch the tubing over the rollers and hang the upstream stopper underneath the peri-pump
3. Recheck the direction of the peri-pump rotation and confirm that the internal standard flows toward the nebulizer.
4. Clamp the tubing by engaging the adjustment arms

Figure 3. Installing the internal standard tubing

3. Installing the sample tubing

1. Hang the downstream sample tubing stopper over the top of the peri-pump.
2. Stretch the tubing over the rollers and hang the upstream stopper underneath the peri-pump
3. Recheck the direction of the peri-pump rotation and confirm that the sample flows toward the nebulizer.
4. Clamp the tubing by engaging the adjustment arms

Figure 4. Installing the sample tubing

4. Adjusting the clamp tension

1. Place the end of the sample and internal standard tubing into pure water.
2. Set the peri-pump speed to 0.1 rps or Normal and gas flow to 0 L/min in the Mass Hunter software.
3. In analysis mode, check that the pure water is reaching the nebulizer and the spray chamber is draining properly.
4. Loosen the clamp tension until the water flow stops.
5. Slowly tighten the sample clamp until the pump draws up the water again. (Introduce an air bubble to better visualize the flow)
6. Repeat with the internal standard clamp.
7. Once water is moving smoothly in both the sample and internal standard lines, add 1–2 extra turns to the tension rods.

Figure 5. Adjusting the clamp tension

Learn how to effectively maintain your Agilent 7800/7850/7900 ICP-MS with MassHunter:  Agilent 7800/7850/7900 ICP-MS with MassHunter eLearning path available from Agilent education