ICP-MS Gas Flow Errors

Answer

This Information Applies To: 7700, 7800, 7850, 7900 Agilent ICP-MS instruments 

Issue

Error messages related to gas flows can cause the plasma to shut off or disable plasma ignition.

The troubleshooting procedure in this article is applicable for the following warnings/errors:

• 1445 Error: Plasma gas flow rate is too low.
• 1446 Error: Aux gas flow rate is too low.
• 2412 Warning: Plasma gas flow rate is low.
• 2413 Warning: Aux gas flow rate is low.
• 2414 Warning: Carrier gas flow rate is low.

Background

Gas flow errors can be due to an empty argon supply, restriction along the argon supply line, a faulty argon regulator, or ICP-MS hardware fault.

Steps to Follow

1. Check the argon supply and verify it is not empty.
   
   
2. Check that all argon valves leading to the ICP-MS are open.
   
   
3. Check that the ICP-MS argon regulator pressure is set between 500 and 700 kPa (73 to 102 psi). In Figure 1, the regulator is set to 95 psi (655 kPa).

   
   
   Figure 1. Argon Regulator set to 95 psi (655 kPa)
   
   

4. Access the Sample Introduction Maintenance menu from  Dashboard > Sample Introduction > Maintenance (Figure 2).
   

   
   
   Figure 2. Sample Introduction Maintenance menu
   
   

5. Check the argon gas tank pressure measured in the software.
   1. In the Manual Control table, check the box next to Open Ar Gas Valve (Figure 3, Item 1). You will hear a click from the ICP-MS.
   2. Note the Ar Gas Tank Pressure value in the Meter and Reading Status table (Figure 3, Item 2). This is the incoming argon pressure measured by the software. This pressure should be very close to the pressure on the argon regulator in step 3.
      

      
      
      Figure 3. Sample Introduction Maintenance menu - Open Argon Gas Valve
      1. Check box to open argon gas valve 2. Argon pressure measured in the software
      
      

6. Manually turn on the gas flows.
   1. In the Manual Control table, check the box next to Open Ar Gas Valve (Figure 4, Item 1).
   2. Double click the 0.00 cell next to Plasma Gas.
   3. Type 15.00 in the cell, then press Enter on your keyboard to manually set the plasma gas flow to 15 L/min.
   4. Use the steps above to also set the auxiliary gas flow to 1.5 L/min and the nebulizer (carrier) gas flow to 0.9 L/min (Figure 4, Item 2).
   5. In the Meter Reading and Status table, note the Ar Gas Tank Pressure value and the gas flow values (Figure 4, Item 3 and 4).
      

      
      
      
      Figure 4. Manual control of gas flows
      1. Check box to open argon gas valve 2. Manually entered gas flow values 3. Argon pressure measured in the software 4. Gas flows measured in the software
      
      

7. Compare the Ar Gas Tank Pressure value from step 4 and 5. Also recheck the argon regulator from step 3. The pressure may have dropped slightly when the gas flows were manually turned on, but the pressure should not drop more than 100 kPa and should still be within 500–700 kPa. 
   If the pressure drop was substantial:
   1. Check for a restriction in the argon supply line. Is the line pinched somewhere between the argon supply and the ICP-MS?
   2. If the same argon tank/dewar supplies multiple instruments, close all other argon supply valves so argon is only being delivered to this ICP-MS and recheck. If the pressure drop is resolved, there was insufficient argon flow from the argon tank/dewar to supply all instruments at the same time. Contact your facilities team.
   3. The argon regulator could be faulty. Replace with a new regulator.
      
      
8. If the Ar Gas Tank Pressure reads -43 kPa regardless of if the Open Ar Gas Valve box is selected or cleared, power cycle the ICP-MS system and retest.
   
   
9. If the gas flows from the Meter Reading and Status table do not match what was input into the Manual Control table, power cycle the ICP-MS system and retest.
   
   
10. If the issue remains, record all values and contact Agilent Technical Support.

Learn how to effectively troubleshoot your Agilent ICP-MS System: Agilent 7800/7850/7900 ICP-MS with MassHunter Agilent 8900 Triple Quadrupole ICP-MS with MassHunter e-learning courses available from Agilent education