A method was developed for the determination of 3-chloro-1,2-propanediol dipalmitate(3-MCPD-DP) in oil by solid phase extraction/liquid chromatography-tandem mass spectrometry.Oils sample was directly dissolved with acetonitrile-isopropanol(1∶1,by volume),and purified with manual-filled PSA+C18 solid phase extraction column.Separation of the analyte was performed on a ThermoFisher Accucore C18 column by gradient elution,using 10 mmol/L formic acid methanol solution and 10 mmol/L ammonium isopropanol solution as mobile phases.The detection was performed by LC-MS/MS in positive electrospray ionization(ESI+) mode under multiple reaction monitoring(MRM) mode,and the quantitative analysis was carried out by the internal standard method.Effects of ionization,content of solid phase extraction(SPE) filler,elution and solution with constant volume were investigated.Under the optimal conditions,the calibration curve for 3-MCPD-DP was linear in the range of 0.5-1 000 ng/mL with a correlation coefficient(r2) more than 0.999.The limit of detection(LOD,S/N≥3) and the limit of quantitation(LOQ,S/N≥10) were 0.025 mg/kg and 0.050 mg/kg,respectively.Average recoveries for 3-MCPD-DP at spiked levels of 0.1-0.5 mg/kg varied from 90.8% to 102% with relative standard deviations(RSD,n=6) of 1.1%-3.0%.The method is simple and sensitive,and is suitable for the detection of 3-MCPD-DP in oils.