Abstract:Rapid evaporative ionization mass spectrometry (REIMS) is a recently developed ambient mass spectrometric technique without any sample preparation. In this study, a real-time lipidomics detection method was developed for fast profiling of Antarctic krill oil on the basis of REIMS. The Antarctic krill oil was extracted using 95% ethanol from freeze dried Antarctic krill. The compounds inside were evaporated by a heating probe at 500 ℃, and the aerosol generated was transferred into the interface of mass spectrometer by a Venturi pump with nitrogen at 2 bar. In the interface, a coil of Kanthal A1 wire (1.1 Ω, 3 V) was set for ion collision. A syringe pump was used to inject the matrix solvent at a flow rate of 0.1 mL/min throughout experiments. The propan-2-ol, together with the aerosol, entered the mass spectrometer via a stainless steel MS inlet capillary. The results showed that the lipid ion peaks were generally produced in the m/z range of 200-900. There are generally two clusters, including the cluster of fatty acid ions at m/z 200-500 and the cluster of phospholipid ions at m/z 600-900. After statistic analysis and lipid identification, a total of 20 fatty acid molecular species and 26 phospholipid molecular species were found. [EPA-H]- (m/z, 21.59%) and [DHA-H]- (m/z 327, 14.44%) were the most abundant fatty acid ions, while [PG 36:7-H]- (m/z 763, 11.67%) and [PC O-38:3-choline]-/[PE O-38:3-NH3]- (m/z 737, 11.46%) were the major phospholipid ions. After method validation, it indicated that the proposed REIMS method was sensitive and precise for high-throughput lipidomics profiling of Antarctic krill oil, which could provide important theoretical basis for mass spectrometry workers and technical support for related enterprise and functional departments.