Abstract A highly sensitive and accurate gas chromatography-mass spectrometry method for rapidly quantitative analysis of dioxane in water samples is described. Dioxane in water sample was extracted by hexane-methylene chloride (80:20, v/v) then transferred to a C 18 solid-phase extraction (SPE) cartridge and eluted by acetonitrile. An aliquot of this solution was analyzed by gas chromatography-mass spectrometry with electron impact ionization and selected ion monitoring (dioxane m/z 88) mode. The quantitative limit was set to be 0.05 μg/ml with an injection volume of 2 μl and a sample volume of 1 ml. The isotopically labelles [ 2H 8]dioxane ( m/z 96) was used as internal standard. Analysis time is approximately 6 min. The results for various kindsd of SPE cartridges in this method are also dicussed.