A new method for determination of dimethyl sulfide was established. Thus dimethyl sulfide formed by heating Satsuma mandarin juices was trapped in the silica gel column and determined quantitatively by gas-liquid chromatography: The column was packed with a mixture of 0.5ml of conc. H₂SO₄ and 1.0g of silica gel. Dimethyl sulfide trapped in the column from juices (Fig. 1) was eluted with ice water and filled up to 25ml to make 2% H₂SO₄ solution. Five milliliters of the acidic solution and 8 μ1 of 5% t-butyl alcohol as an in-ternal standard were introduced into a 125ml Erlen-meyer flask and stoppered tightly, and incubated 20min at 25°C. The head space gas was injected into the gas-liquid chromatograph. The calibration curve gave a linear relationship between 30 and 150 ppb (Fig. 2).