What are active compounds and not active compounds

[Analisis]

Hello,
I have many years working in gas and liquid chromatography, however I have many basic questions because I have not clear many concepts. Can someone clarify what are active compounds and inacitive compounds in chromatography? I have searched in internet and have read some books but have not yet a definition of what are an active compound and a non active compound.
Thank you for your answers.
Análisis

[James_Ball]

I would guess if working in pharmaceutical laboratory it would be the difference between the active ingredient and the excipient filler ingredients in a drug. This is something like 100mg of Acetaminophen (active) in a tablet that weighs 500mg, the extra 400mg being not active compounds.

If talking only about chromatography, it is usually whether a compound is degraded by the system. Active compounds such as DDT, will break down into other compounds such as DDE and DDD when the GC inlet is dirty. Pentachlorophenol will also break down in a dirty GC inlet or will make a long tailing peak if there are many active sites present in the system.

[Peter Apps]

In chromatography an active compound is one that interacts with active sites and causes a tail on the back of the peak. Depending on compound and system "activity" can be caused by almost anything. If you see a tial on thepeak, you have activity.