This paper reports the results from studies conducted to determine if Ion Mobility Spectrometry (IMS) could be used to find small amounts of plastic in a matrix of heated seedcotton.  Modified versions of commercial IMS analyzers equipped with membrane inlets sampled air in a commercial gin drying system as seedcotton and seedcotton containing plastic passed through the system.  Vapors from plastics associated with cotton contamination were detected with IMS in negative polarity; different plastics were distinctive.