AICMM wrote:
Samba_zero,
I see three issues with your chromatogram and do not speak directly to your integration question (my apologies.)
First, for an FID, you seem to have a lot of noise. The pattern in front of the large peak suggests an electronic noise problem of some sort since it repeats (although I would expect it after the peak as well....?) If you are watching the FID signal, how many pA's of swing are you getting when sitting idle?
Second, it appears to me you have a peak width threshold (or slope sensitivity ) that is inappropriate since you are calling out lots and lots of peaks that are really just baseline noise.
Finally, the fronting of your peak is not really an integration issue, it is a chromatographic issue. IF this were a valve injection (I am betting it is not...) I would say you have a leaky rotor but something is certainly getting on column when it should not be...
Fix the chromatography issues first, then tackle the integration.
Best regards,
AICMM
Thank you for the suggestions, there may be something wrong with the instrument, unfortunately I can't change or even repair much on the instrument myself, I would have to discuss this with the lab manager first.
The autosampler makes the injection method via the injection port. I can't say more about this at the moment, I can't just look inside the device to check for leaks.
No manual injection!With standard
rinse
however, I had made several flushes, I can no longer say exactly between which measurement this flush was made?
Is it possible that some of the carboxylic acids absorb onto the column and gradually detach from it again on the next measurement?
Peter Apps wrote:
The plateau in front of the peak with a little spike at its leading edge is a classic solvent effect - what are you injecting, what volume and under what conditions (inlet split ratio, inlet and column temperatures)?
Don't worry about the flat top on the big peak - it is just the plot going off the top of the chart.
Peter
Thank you, its a WAX Elite column at 240 °C, split and volume I must check don't know the data at the moment.
What is a solvent effect, can tell me please more about this?
Ok I iwill first try to find someone to help me with the hardware. should i also use another column?
Best Regards