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Am I using the correct detector configuration for my 6890 GC?

Question asked by megaflorch on Aug 7, 2019
Latest reply on Dec 17, 2019 by james_jenkins




I have had a fair amount of success with posted questions in this forum, so here is another one. I am interested in knowing more about whether the flame ionization detector I have equipped on my HP/Agilent 6890 GC is the correct detector for the types of analysis that I run. Primarily, I run my GC, not to discover and name unknown compounds in a mixture, but to determine the weight percentage(w/w) of any particular analyte in a mixture. For example, in say a quality assurance capacity, I need to know the exact weight percentage of a particular analyte of a pre-mixed solvent mixture. So far, utilizing the FID, I can determine a fairly close weight percentage amount in a mixture that would have an expected result, but it is not exact. For quality assurance purposes, I desire a more precise result. This forum has assisted me in developing a method that does that. Recently, I spoke with someone who suggested that the FID detector may be creating more interference than cohesion as far as results go. I also understand that the nature of the compounds I am evaluating, (volatile, low boiling, low surface tension, azeotropic, vapor degreasing solvents)but  I am wondering if the absence of the FID detector would improve my results. I am not informed about the operations or typical methodology of detectorless GC or base model GC use. Maybe some old school analysts can weigh in on this. Any feedback I would consider helpful. Thanks!