Abstract: A pre-treatment method of nitrobenzene was studied by solid phase extraction in grain. According to characteristic of different kinds of grain, nitrobenzene in low fatty grain was directly extracted by n-hexane, and high fatty grain was extracted with acetonitrile in pre-treatment procedures, then extraction of acetonitrile was transferred into n-hexane by liquid extraction method. Aluminum oxide was used as main stuffing in solid phase extraction, and weaker polar impurity was washed with n-hexane and stronger polar particulate was washed with reagent of ethyl acetate-hexane (6+4) respectively. Elution of stronger polar reagent that 5 ml ethyl acetate was used because of concentration demand, and the effect was perfect. Concentration and purity of the determination method of nitrobenzene were isochronous and the loss problem was resolved in pre-treatment procedures of concentration. The pre-treatment method was also confirmed by gas chromatographic-mass spectrometry. A simple, available and economic pre-treatment method was established with the characteristics of low disturbance, convenience and high sensitivity in this study.

Key words: nitrobenzene, solid phase extraction, pre-treatment, grain