Abstract: Tri-n-butylammonium-p-toluenesulfonate was prepared and its solution in dichloromethane was applied statically to silica capillary column (i.d.0.53 mm×30 m) with 1.2 μm in liquid membrane thickness,which was used as stationary phase in gas chromatography.As shown by the results of performance test,relatively strong polarity and specific capability for separation of benzoyl peroxide from wheat flour were manifested by this stationary phase.In its application to the GC-determination of benzoyl peroxide in wheat flour,precision was tested on 3 different concentration levels,giving values of RSD′s (n=5) in the range of 1.1%-5.0%.Linear relationship between the peak area and concentration of benzoic acid was found in the range of 10 to 100 mg·L-1 (r=0.994),with a detection limit of 2.0 mg·kg-1.Recovery test was made and the results obtained were in the range of 94.3%-96.6%.