Problems with using Nitrous Oxide flame. AA240FS

Hi, I have been having problems with our AA240FS's Nitrous oxide burner.

We recently purchased a new MK7 nitrous oxide burner, I was trying to measure Vanadium with it but i get no signal at all from it, i tried up to 1000ppm solutions and not even the tiniest bit of signal. Also tested with Titanium and got the same results.

I think it might have something to do with the gas flows, i am not seeing the characteristic red cone of the nitrous oxide flame no matter how i try to change the flame stoichiometry. I am using good quality nitrous oxide and Acetylene, both fed at pressures well within the recommended ranges. What might be the problem? I have tried all i can think of: Burner positioning, Different lamps, adjusting nebulizer, adjusting sample uptake rate, even using an A/A flame. The lamps are fully functional as shown by them giving good results when installed into our GFAAS.

I am running out of ideas on what to do, anyone have anything that might solve this?

  • It could be the gas flows, in which case, you should contact your local Agilent service team to schedule a repair.

  • Hello

    Please make sure that "N20/Acetylene" Is selected as the flame type in your method. If Air/Acetylene is selected, an Air Acetylene flame will light and run on a Nitrous burner. A Nitrous flame initially lights on Air/C2H2, and then switches over to N20 after a few seconds only if it is selected in your method. It is a very noticeable switch, you should see a taller, richer flame. If N20/Acetylene is selected in your method and you're still not seeing signal, then please follow what Tina suggested. Have a good day

  • Hi, It seems to switch over to the N2O flame but it is very lean and light blue. No matter how i adjust the gas flows there is no red cone to be seen, i adjusted the Acetylene up to 8l/min as it says in the "AA Troubleshooting and Maintenance Guide" on page 8 with the N2O at 10.5l/min. There seems to be no change in the flame no matter the flow settings. I wonder if there is something wrong with the flow adjustment system?

  • I would recommend to begin the process of opening a service call. You should see a change in flame stoichiometry as the gas flows are adjusted. It could be an issue with the valves but to know for sure would require on site troubleshooting. Have a good day

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