Abstract

Young Researchers' Sessions (Int'l)

Day 3, June 12（Wed.）　9:45-10:00　Room A (Convention Hall 300)

Lipidomics faces challenges in accurate identification due to coeluting isobars, yielding misleading MS/MS fragments. With studies focus on human plasma, scientists may overlook how variations in lipid composition across different types of biological samples can cause erroneous analytical results. Given the diverse phospholipids (PLs) composition in organisms, significant interference in phospholipidomics analysis is anticipated.
Combining RT-XLOGP3 regression with head-group specific MRM to analyze human whole blood samples revealed challenges: among 335 identified PL species, 40 isobaric pairs causing mutual interference, 49 species affected by other PL isotopes, and 52 PL species prone to erroneous identification at the fatty-acyl level. Notably, coeluting isobars of PS and PC(O-) under different RPLC conditions complicated ether-PCs analysis.
To mitigate errors and ensure broad applicability, we employed LC-MRM coupled with enhanced in-source fragmentation (LC-ISF-MRM) to address chimeric spectrum issues. PC and PS tend to undergo neutral loss of headgroup-specific fragments at lower collision energies, generating distinct m/z intermediate ions. Optimizing the method with fragmentor voltages of 290 V for PC and PS facilitated acquisition of a "clean" FA side chain spectrum. This strategy enriches the LC-MS/MS toolkit, enabling more accurate lipidomics results and enhancing understanding of PLs, with the potential to reveal novel therapeutic targets.

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