Abstract: Solid phase extraction (SPE) and gas chromatographic/negative chemical ionization-mass spectrometric （GC/NCI-MS） method was developed for the determination of 3-monochloropropane-1,2-diol (3-MCPD) in hydrolyzed vegetable proteins (HVP) and soy. The optimized conditions for the extraction and cleanup of 3-MCPD on an Aoisa-HBL column were investigated. The extract with hexane-ethyl acetate was evaporated to nearly dry by N2 at 40 ℃ and derivatization was performed with 1-(heptafluorobutyryl) imidazole at 70 ℃ for 30 min. The mixture was then injected into a gas chromatograph with a DB-5MS capillary column, detected by a mass spectrometer in negative chemical ionization and selected ion monitoring mode (NCI/SIM) and quantified with external standard calibration. The limit of quantitation (LOQ) for 3-MCPD was 0.5 μg/kg. The average recovery was in a range of 92.2%-97.4% with a relative standard deviation range of 3.6%-10.9%. The results indicated that the method could be used for the sensitive and accurate determination of 3-MCPD in foods and agriculture products.

Key words: 3-monochloropropane-1,2-diol, hydrolyzed vegetable proteins, negative chemical ionization （NCI）, selected ion monitoring （SIM）, solid phase extraction （SPE）, soy , gas chromatography/mass spectrometry （GC/MS）