Two Complementary Reversed-Phase Separations for Comprehensive Coverage of the Semipolar and Nonpolar Metabolome

Naser, F.J.; Mahieu, N.G.; Wang, L.; et al.

Described here by Patti and colleagues is an improved LC-MS strategy for untargeted profiling of semi-polar (logP -2 to 1.5) and non-polar (logP 1.5 to 35) metabolites present in the neurotransmitter and lipid metabolism pathways. In their evaluations, method benchmarking was facilitated by authentic standards and E. coli cell extracts used together with the credentialing algorithm. The results revealed a tandem RP-LC approach (CORTECS T3 and C8 columns) to be superior for moderate-to-low polarity metabolites (e.g., phospholipids, triacylglycerols, nucleotides, nucleobases) relative to reference methods often used in metabolomics, delivering a 5-fold increase in the credentialed coverage over this molecular range. Complementing this approach with HILIC-MS extended the breadth for comprehensive metabolite profiling.