Atmospheric pressure ionization mass spectrometry (APIMS) was used to detect hydrocarbons; e.g., methane, ethane, and propane, and organic cleaning solvents; e.g., isopropyl alcohol (IPA) and acetone in nitrogen. The technique of collision-induced dissociation (CID) was used to fragment parent molecular ions by acceelerating them through the declustering region of the APIMS source in an effort to detect the hydrocarbon impurities at a single m/e. Using high declustering voltages it is possible to detect all the compounds studied, except IPA, at m/e 12 (C+). At moderate declustering voltage fragments characteristic of the compounds of interest can be used for monitoring and identification purposes.