Bypassing the AVS for the 5000 Series ICP-OES

Answer

This Information Applies To: 5000 series ICP-OES (5100,5110,5800,5900), AVS 4/6/7

Issue

Steps to bypass the AVS to troubleshoot poor performance on the ICP-OES

Tip: These steps should be completed after the Subsystem Communication, Air Flow, Water Flow, Gas Flows, RF Generator, Camera, and Optics Tests have been completed with a status of ‘Done’ or ‘Pass’

Bypass (or skip) the AVS to run a worksheet and troubleshoot instrument performance issues such as sensitivity and precision. The root cause may be related to an AVS component, the method application, or an instrument fault and bypassing the AVS helps identify the root cause.

With the AVS 6/7 installed on the 5000 series ICP-OES, the sample introduction area will look like Figure 1 (AVS 6) or Figure 2 (AVS 7). The setup difference between the AVS 6 and AVS 7 is the seventh port on the AVS 7 valve for the internal standard. An internal standard tube must be installed on the peristaltic pump.

Figure 1. AV6 connections
1 To Autosampler, 2 To carrier, 3 To waste

Figure 2. AVS 7 connections
1 To AVS, 2 To waste

Steps to follow

1. Disconnect the UniFit sample connector from the nebulizer. Unscrew the threaded flangeless fitting from port 2 of the AVS, remove, and set this fitting aside. It will not be used when bypassing the AVS (Figure 3):

   
   Figure 3. UniFit sample connected to the nebulizer and Port 2 of the AVS

2. Disconnect the barbed end (labeled “Peri Pump Rinse”) of the T-piece from the rinse tubing on the peristaltic pump (Figure 4):

   
   Figure 4. Peri-Pump rinse connector 

3. If an internal standard line is installed on the AVS 7, unscrew the threaded internal standard fitting from port 7 of the AVS and remove the tubing from the peristaltic pump. Set the internal standard tubing and connection aside. It will not be used when bypassing the AVS (Figure 5):

   
   Figure 5. Internal Standard Line connector

4.  Locate the UniFit sample connector, 0.75 mm id, for U-Series SeaSpray concentric nebulizer. This connector is included with a new nebulizer (Figure 6):

    

   Tip: This connector is also available to order as a pack of 10 (Agilent part number G8010-80035).

   
   Figure 6. UniFit connector

5. Attach the UniFit sample connector to the nebulizer and insert the capillary tube end into the rinse tubing on the peristaltic pump (Figure 7):

   
   Figure 7. Connector and Rinse Tubing connected

6. Remove the autosampler threaded fitting from port 5 on the AVS that connects the autosampler probe tubing to the valve (Figure 8):

   
   Figure 8. Port 5 of the AVS

7. Locate the ICP-OES connection kit, Autosampler to Peristaltic Pump (p/n G8010-60348). Find the small rectangular block with a barb on one end and a threaded port on the other end. If you:
   
   1. Have this block: Attach the autosampler threaded fitting into the threaded port of the small rectangular block and insert the barb into the free end of the rinse tubing on the peristaltic pump. This peristaltic pump tubing will no longer act as a rinse line but will now be the sample line and will deliver the solution to the nebulizer, bypassing the AVS valve.
   2. Do not have this block: Pull the threaded autosampler connection fitting off the autosampler capillary and insert the autosampler capillary end into the free end of the rinse tubing on the peristaltic pump. This peristaltic pump tubing will now be the sample line and will deliver the solution straight to the nebulizer, bypassing the AVS valve. It is recommended to have spare autosampler connection fittings available (p/n G8010-60306).

8. Clamp the peri-pump tubing, send the autosampler to a vial containing DI or rinse, turn on the peristaltic pump, and confirm that the solution is being delivered to the nebulizer at a smooth steady rate. Confirm that the spray chamber is draining. Adjust the roller arm tension for the sample and drain if needed. Turn off the peristaltic pump when completed.

9. Perform an ICP-OES ICP-OES Detector and Instrument Calibration 

Learn how to effectively troubleshoot your Agilent AVS7 on the 5000 Series ICP-OES: Agilent 5000 Series ICP-OES Maintenance and Tips for Optimal Performance e-learning course available from Agilent education