[Determination of 15 lipid regulators in fish meat by QuEChERS-ultra performance liquid chromatography-quadrupole/...

An analytical method was established for the determination of 15 lipid regulators in fish meat by QuEChERS combined with ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap mass spectrometry (UPLC-Q/Orbitrap-MS). The samples were purified by optimized QuEChERS methods. The amounts of the adsorbent materials (primary secondary amine (PSA) (20, 60, 100, 140 and 180 mg), C18 (40, 100, 160, 220 and 280 mg) and sodium acetate (0.2, 0.6, 1.0, 1.4 and 1.8 g)) were optimized by the response surface method to obtain the best purification effect. The target compounds were separated on an XBridge-C18 column (100 mm×2.1 mm, 3.5 μm) using acetonitrile-0.1% (v/v) formic acid aqueous solution (containing 1.5 mmol/L ammonium acetate) as the mobile phases by a gradient elution program. Qualitative and quantitative analysis of the target compounds were performed in the full scan and secondary mass spectrometry scan (dd-MS²) modes with positive and negative ionization. The target compounds showed good linear relationships in their respective ranges, with correlation coefficients (R²) greater than 0.99. The limits of detection (LOD, S/N=3) and limits of quantification (LOQ, S/N=10) were in the range of 0.2-1.0 μg/kg and 0.3-3.1 μg/kg, respectively. The average recoveries were 76.4%-116.0% at LOQ, 2-fold LOQ, and 10-fold LOQ levels. The intra-day relative standard deviations (RSDs) were 1.0%-7.9%, and the inter-day RSDs were 1.7%-18.4%. The method is simple, sensitive and accurate, and it is suitable for the determination and quantification of lipid regulators in fish meat.