Comprehensive profiling and sensitive quantification of gangliosides in mouse brain based on boron-doped TiO2 composites coupled with UPLC-cIM-MS/UPLC-QQQ-MS/MS

Boron-doped TiO 2 enabled dual-mode enrichment of gangliosides from mouse brain. • Optimal conditions gave >98% elution efficiency and stable reuse over 6 adsorption–elution cycles. • UPLC-QQQ-MS/MS validation showed 2.5 enrichment factor, 44.5–116.9% recovery, and low LOD/LOQ. • UPLC-cIM-MS identified 33 gangliosides (8 subclasses), including 3 novel species. Gangliosides (GGs) play a crucial role in the development of the mammalian nervous system. However, due to their low content and significant matrix interference, the detection of these substance poses substantial challenges. In this study, considering that gangliosides contain a glycan headgroup with sialic acid residues, boron-doped titanium dioxide composites were prepared to enrich the GGs from mouse brain tissue by utilizing the specific affinity of boric acid for cis-diols of glycan and electrostatic attraction between TiO 2 and sialic acid ion. To optimize the extraction and elution parameters, a method of UPLC-QQQ-MS/MS was developed using the GGs standards, and then the extracts were analyzed by this method. The results showed that the boron-doped TiO 2 material significantly reduced matrix interference, with an average enrichment factor of 2.5 and recovery ranging from 44.5% to 116.9%. The limit of detection (LOD) was 0.5–20 μg/L, and the limit of quantification is 2–70 μg/L. To discover additional and novel GGs, the extracts underwent UPLC-cIM-MS to get the comprehensive profiles of GGs. Finally, 8 subclasses and 33 molecular structures of GGs were identified, and three new substances were discovered, which showed that boron-doped titanium dioxide composites coupled with LC-cIM-MS provide an effective strategy for the highly sensitive detection of GGs. Furthermore, this approach holds a great promise for expanding studies on GGs profiles in other complex biological samples.