This standard describes the method for the determination of toluene, acetone and butanone in Coatings by top air phase chromatograph mass spectrometry. It is suitable for the determination of toluene, acetone and butanone in Coatings and Miscellaneous samples containing nonvolatile components. The principle of the method is to dissolve the sample in ethyl acetate, then use top air phase chromatograph-mass spectrometry for one-time analysis and detection, and finally use external standard method for quantification. The required instrumentation and reagents include gas phase chromatograph Mass Spectrometry (MS), headspace Sample injector, Balance, volumetricflask, pipette, top empty bottles, etc., as well as toluene, acetone, butanone, ethyl acetate and other chemicals. In the analysis step, the sample is first prepared into ethyl acetate solution, then headspace injection is carried out, and finally the operating conditions of the instrument are set.