posted on 2022-01-13, 19:04authored byHarald Schoeny, Evelyn Rampler, Dinh Binh Chu, Anna Schoeberl, Luis Galvez, Markus Blaukopf, Paul Kosma, Gunda Koellensperger
Standardization is
essential in lipidomics and part of a huge community
effort. However, with the still ongoing lack of reference materials,
benchmarking quantification is hampered. Here, we propose traceable
lipid class quantification as an important layer for the validation
of quantitative lipidomics workflows. 31P nuclear magnetic
resonance (NMR) and inductively coupled plasma (ICP)–mass spectrometry
(MS) can use certified species-unspecific standards to validate shotgun
or liquid chromatography (LC)-MS-based lipidomics approaches. We further
introduce a novel lipid class quantification strategy based on lipid
class separation and mass spectrometry using an all ion fragmentation
(AIF) approach. Class-specific fragments, measured over a mass range
typical for the lipid classes, are integrated to assess the lipid
class concentration. The concept proved particularly interesting as
low absolute limits of detection in the fmol range were achieved and
LC-MS platforms are widely used in the field of lipidomics, while
the accessibility of NMR and ICP-MS is limited. Using completely independent
calibration strategies, the introduced validation scheme comprised
the quantitative assessment of the complete phospholipid sub-ome,
next to the individual lipid classes. Komagataella
phaffii served as a prime example, showcasing mass
balances and supporting the value of benchmarks for quantification
at the lipid species level.