This standard specifies the gas chromatograph/mass spectrometry method for the determination of monobutyltin, dibutyltin, tributyltin, monophenyltin, diphenyltin, triphenyltin, tricyclohexyltin, and dioctyltin in Coatings. It is suitable for the determination of 8 kinds of organotin in Coatings. The summary of the method includes that the sample is purified by strong cation exchange solid phase extraction column, derived from sodium tetraethylboride, and then determined and confirmed by gas chromatograph/Mass Spectrometry (MS), and finally quantified by external standard method. The reagents and materials include sodium tetraethylboride, ethyl acetate, methanol, n-hexane, ammonium chloride, glacial acetic acid, sodium acetate, sodiumhydrate, and organotin standards.