Quantitative determination of sn-positional phospholipid isomers in MS < sup > n < /sup > using silver cationization

Anal Bioanal Chem. 2022 Jun 22. doi: 10.1007/s00216-022-04173-6. Online ahead of print.ABSTRACTGlycerophospholipids are one of the fundamental building blocks for life. The acyl chain connectivity to the glycerol backbone constitutes different sn-positional isomers, which have great diversity and importance for biological function. However, to fully realize their impact on function, analytical techniques that can identify and quantify sn-positional isomers in chemically complex biological samples are needed. Here, we utilize silver ion cationization in combination with tandem mass spectrometry (MSn) to identify sn-positional isomers of phosphatidylcholine (PC) species. In particular, a labile carbocation is generated through a neutral loss (NL) of AgH, the dissociation of which provides diagnostic product ions that correspond to acyl chains at the sn-1 or sn-2 position. The method is comparable to currently available methods, has a sensitivity in the nM-µM range, and is compatible with quantitative imaging using mass spectrometry in MS4. The results reveal a large difference in isomer concentrations and the ion images show that the sn-positional isomers PC 18:1_18:0 are homogeneously distributed, whereas PC 18:1_16:0 and PC 20:1_16:0 show distinct localizations to sub-hippocampal structures.PMID:35731255 | DOI:10.1007/s00216-022-04173-6

Source: Analytical and Bioanalytical Chemistry - June 22, 2022 Category: Chemistry Authors: Johan Lillja Ingela Lanekoff Source Type: research