GC/MS IONTRAP EJECTION OF IONS
Posted: Mon Jan 11, 2010 5:14 pm
by sundaresan
HI,
I am working on varian 450gc coupled with 240ms. But still i am not clear about the dc and rf potentials used in ion trap .How this helps in trapping and ejection of ions from the trap.
The ions eject from the trap once its unstable.But i wonder how this happens.
Can anyone tell me the theory of this?
Cheers
Posted: Mon Jan 11, 2010 7:27 pm
by yanner
Hi… I am thinking about to buy a Varian 240-MS/450-GC Ion trap system. I wonder if you had the possibility to compare this apparatus with a single quadrupole GC/MS system. And the most important… can you use libraries (NIST, PMW, Wiley) without any problems? Are the proportions of the signals for the substances in the MS spectrum similar with the signals in the libraries?
varian 450GC/240MS
Posted: Mon Jan 11, 2010 8:21 pm
by sundaresan
Hello yaneer,
My 240 MS system is equiped with,
Ion trap, scanning range upto 1000, with both electron and chemical ionization, it uses internal ionization.
But i would suggest you to get MS/MS too its nothing but small chip embedded to your system even it doesn't cost much, It will be very usefull.
In single quadrupole you cant perform MS/MS ,This should be considered.
The instrument is very straight forward,robust and simple to use. Even MS workstation software is good enough.
They gave me NIST and WILEY library.The library has more than 100,000 compounds and its match with mass spectra is excellen,Library provides lot of information like retention index of the compound,GC methods,synoms etc.
And wiley library 50,000 compounds its mainly used for pesticide compounds.
NIST has MS/MS option.
Overall instrument performance is efficient and good
good luck
cheers