We use a GC-MS-FID system in combination with a thermal desorber. I wonder what the FID is good for? One argument I have read is that the FID is probably suitable for higher concentrations. But that is not a good argument in our case, because we can repeat the sample after re-collecting with a higher split. Another argument I heard is that the FID is better at quantifying unknown substances or non-calibrated substances using a semi-quantitative evaluation. In a test with around 20 different substances with the same concentration, however, I noticed that the chromatograms of the TIC of the MS are more uniform than those of the FID. The semi-quantitative evaluation of these substances is also much better with MS. As soon as halogen compounds are involved, there is much less signal. In my opinion, the biggest disadvantage of FID in combination with MS is that the splitter makes it more complicated and makes troubleshooting more difficult. In addition, helium consumption is higher. Can anyone tell me why you might need a FID in addition to the MS?
