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- Posts: 6
- Joined: Sun Mar 20, 2011 10:33 am
I noticed that Agilent chemstation has a BFB.u tune file. Can the instrument be tuned automatically by just clicking "BFB tune"?
I tried the following procedures provided by a GCMS practical handbook by Wiley interscience, but I got stucked halfway. These are the instructions from the handbook:
To run a bromofluorobenzene tune for volatile organics analysis, set you GC oven to 230 degrees. Open the cal gas valve and run a target tune or ramp your entrance lens so that 131 and 219 are nearly equal, but slightly favouring 131. Ideal conditions are 69 (100%), 131(35%), 219 ( 30%), 414 (1-2%), and 502 ( 0.8%). Tweak the last two masses with your amu offset and the EM emission. Save tune parameters. Close the cal gas valve.
Shoot 50ng of BFB solution. You should get a single peak at about 17.5 min on the chromatographic display shows a spectrum and a pass/fail tune report for BFB.
What I did was I set my GC oven at 230 degrees Celsius. After autotuning, I open the manual tune window, go to more parameters, change the masses to 69, 131 and 219. I close that window and was at the manual tune window with all the different parameter values again. I click on entrance lens value and changed it, click ramp on the manual tune window. After doing so, I do a scan to see if my 131 and 219 are about the same abundance. They could not reach the ideal percentage as stated. But roughly around 47% for both. I tried to vary amu offset and EM volts, but the percentage for 414 and 502 did not vary much, constantly around 3%, so I just took the autotune value for both. I close gas valve and save the tune parameters as a new file. I manually inject 50ng of BFB, but then I realise that the system did not automatically generate the BFB tune report with the target masses, rel. to mass, lower limit %, upper limit %, Rel abundance, Raw abundance, Result pass/fail. What I don't understand is how can the BFB peak be shown on the chromatographic display when I am not even doing a run. Do I need to run BFB using an temperature gradient? How do I generate a BFB tune report??
I don't know if I am doing this correctly or not. Please correct me. Thank you!!
