Direct infusion ESI–MS analysis for metabolite profiling of human plasma using various fractionation techniques

Background: Metabolomics is a real challenge owing to the complexity and chemical heterogeneity of biological samples. In this study, a comparative analysis of metabolite profiling using ten metabolite extraction techniques were investigated on a pooled plasma sample followed by direct infusion ESI–MS analysis on both positive and negative modes. Methodology & Results: Metabolites from a pooled sample of 50 healthy volunteers were separated one- and two-dimensionally utilizing solvent precipitation, solid-phase extraction and molecular weight fractionation. Numbers of unique metabolites that are specific to a particular sample preparation approach were also identified by online available database, Metlin. The 1H NMR study...