TiO2/SiO2 Core–Shell Composite-Based Sample Preparation Method for Selective Extraction of Phospholipids from Shrimp Waste Followed by Hydrophilic Interaction Chromatography Coupled with Quadrupole Time-of-Flight/Mass Spectrometry Analysis

A solid-phase extraction (SPE) procedure, using titania-coated silica (TiO2/SiO2) core–shell composites as the sorbent, combined with a liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for extraction, visualization, and quantification of phospholipids in shrimp waste (Litopenaeus vannamei). The SPE protocol was optimized, and the best conditions were pH 5 of the loading solvent, 10% aqueous methanol as the washing solvent, and 1.0 mL of chloroform/methanol (1:2, v/v) as eluting solvents. Afterward, the eluate was separated on a diol hydrophilic interaction chromatography (HILIC) column. A total of 69 phospholipid species were identified and determined. The results indicated that, in comparison to previously published methods, this strategy was cost-effective and efficient in extraction, characterization, and determination of phospholipids. Meanwhile, phospholipids were abundant in shrimp waste, most of which contained unsaturated fatty acyl chains, such as 18:3 [α-linolenic acid (ALA)], 20:5 [eicosapentaenoic acid (EPA)], and 22:6 [docosahexaenoic acid (DHA)]. The successful application of this strategy paves the way for full use of traditionally discarded shrimp wastes.