Enhancing coverage in LC-MS-based untargeted metabolomics by a new sample preparation procedure using mixed-mode solid-phase extraction and two derivatizations.

Enhancing coverage in LC-MS-based untargeted metabolomics by a new sample preparation procedure using mixed-mode solid-phase extraction and two derivatizations. Anal Bioanal Chem. 2019 Aug 14;: Authors: Wu Q, Xu Y, Ji H, Wang Y, Zhang Z, Lu H Abstract It is a challenge to expand the metabolome coverage of liquid chromatography (LC)-electrospray ionization (ESI) mass spectrometry (MS) based untargeted metabolomics analysis. The limited coverage is attributed to the weak signal of hydroxyl and carboxyl groups in ESI-MS and the limited capacity of LC separation for metabolites with a wide range of polarities. Here a new sample preparation procedure is proposed to solve these problems. Mixed-mode (reversed-phase and anion-exchange) solid-phase extraction sorbents were used to separate metabolites into hydrophilic amine, hydrophobic amine/alcohol, and organic acid groups. Then, alcohols and carboxylic acids in separated groups were tagged with pyridine with use of two derivatization systems for signal enhancement. Finally, hydrophilic amines were analyzed by LC-MS with a hydrophilic interaction LC column, and the two hydrophobic compound groups were analyzed by LC-MS with a C18 column. From the results for standard samples, the detection limits of the new method are lower than those of the classic solvent extraction-protein precipitation method by 3.3-70 times for five amino acids and by 65-1141 times for five fatty acids. Moreover, the d...
Source: Analytical and Bioanalytical Chemistry - Category: Chemistry Authors: Tags: Anal Bioanal Chem Source Type: research