Triazole Hydrophilic Interaction Chromatography Mass Spectrometry–Based Method for Studying the Lipidomic Composition of Largemouth Bass (Micropterus salmoides) with Different Feeds

A triazole hydrophilic interaction chromatography mass spectrometry (HILIC-MS) method was developed for lipidomics studying the largemouth bass (Micropterus salmoides). The effect of feeds, especially the frozen trash fish and artificially formulated feed, on the phospholipid composition was evaluated. The results showed that the phospholipids could be well separated in the order of phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol and phosphatidylserine. Under negative-ion mode, all the phospholipids were ionized by deprotonating as [M-H]− or adducting as [M + HCOO]−. The mass spectrum for each phospholipid class was inspected and a total of 34 phospholipid molecular species (PMS) was identified. Each PMS was extracted by its ion chromatography and quantified using a linear regression model. The calibration curves were linear ranging from 2.00 to 200 μg mL−1 (R2 0.9988–0.9991) with the limit of detection (LOD) and limit of quantitation (LOQ) of 0.15–0.52 μg mL−1 and 0.80–1.80 μg mL−1, respectively. The results indicated that the HILIC-MS method was efficient and reliable in lipidomics analyzing largemouth bass. After orthogonal partial least squares discriminant analysis (OPLS-DA), the major contributors to the difference of largemouth bass samples with different feeds were revealed as PE 760.8, PC 842.8, etc. and validated by permutation test with the intercepts of R2 = (0.0, 0.876) and Q2 = (0.0, − 1.21).