qShot MALDI analysis: A rapid, simple, convenient, and reliable quantitative phospholipidomics approach using...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Mass Spectrometry

Background:

• Matrix-assisted laser desorption/ionization mass spectrometry (MALDI/MS) is useful for phospholipid (PL) analysis.
• Quantitative PL analysis using MALDI/MS is hindered by the lack of affordable isotope-labeled internal standards (interSTDs).

Purpose of the Study:

• To investigate and validate the use of only two PL interSTDs for normalizing entire PL species in complex bio-lipid backgrounds.
• To develop a cost-effective, reliable quantitative method for PL analysis using MALDI/MS.

Main Methods:

• Utilized two phospholipid interSTDs to normalize PL species in urinary lipid extracts.
• Compared the performance of the novel normalization method (ionSTD) against traditional methods like total ion current and matrix-peak normalization.
• Evaluated linear regressions, intra-day, and inter-day precision for various PL subcategories.

Main Results:

• Normalized intensities using ionSTDs showed superior linear regressions (R² > 0.984) compared to traditional methods.
• The ionSTD method demonstrated superior intra-day precision for all analyte concentrations.
• Inter-day precision for negatively charged analytes was statistically better with the ionSTD method, while positive analytes showed comparable precision.

Conclusions:

• Developed a cost-effective, fast, simple, and reliable quantitative method termed "qShot MALDI analysis" for PLs.
• The qShot MALDI analysis, especially in negative mode, shows potential for clinical biomarker screening.
• The use of minimal interSTDs offers a practical solution for quantitative MALDI/MS analysis of phospholipids.