Chromatography Forum

Dear all senior,

This is my first time posting topic in this forum and I am new user on GCMS. I have problem on my GCMS that have high mass spectra background on blank sample. I tried related topic from this forum and tried some possiblity, but still no progress . From tune report (atune), all parameter is ok, and indicate no leak, the only thing make me doubt is the amount of peak on tune file is out of normal (around 800 peak). What is the problem on my case so my mass spectra have high background? I really hope any advice from all seniors here . Thank you in advance for the answer

For the information i used agilent 7890A with 5975C inert XL EI/CI MSD with triple-axis detector, and this GCMS coupled with olfactory port.

warms regard,


dsarf - indonesia

Three is always some background noise in an instrument. When you tune the instrument, there is a fairly strong signal for the tuining compund - an dnoise is very small relative to that signal (unless you have a major problem). The question is how much noise is there and what is the nature of the noise.

Noise can result from column bleed or retained compunds eluting from the column. This requries examination of the spectrum showing for the noise. Do you see ions standing out of the noise that would correspond to ions expected in column bleed for the column you are using? (And are you running samples with tarry components, balsams, or such?)

Also acquisition parameters can have an effect on noise.

Can you find a peak for a known compound like OFN? Can you see a peak for OFN close to the concentration used for instrument checkout - with acquisition parameters used in instrument checkout?