Abstract: GC and MS in hyphenation was applied to the determination of impurities in butylacrylate (BAT).It was confirmed that among the impurities,aminobenzene was a pollutant introduced during transportation,and that the aminobenzene was the source of red coloration of BAT upon addition of acrylic acid in its usage.Under optimized conditions of temperature (25 ℃) and time (2 h) of extraction,SPME was used for enrichment of the pollutant,and it was further studied by GC-MS.As shown by the analytical results,the red coloration was produced by the reaction product of aminobenzene and acrylic acid.Based on the mass spectra of the red colored compound,mechanism of the reaction was discussed.