Ammonium Fluoride as Suitable Additive for HILIC-Based LC-HRMS Metabolomics
Abstract
Hydrophilic Interaction Liquid Chromatography (HILIC) chromatography is widely applied
in metabolomics as a complementary strategy to reverse phase chromatography. Nevertheless, it
still faces several issues in terms of peak shape and compounds ionization, limiting the automatic
de-convolution and data semi-quantification performed through dedicated software. A way to
improve the chromatographic and ionization performance of a HILIC method is to modify the
electrostatic interactions of the analytes with both mobile and stationary phases. In this study, using
a ZIC-HILIC chromatographic phase, we evaluated the performance of ammonium fluoride (AF)
as additive salt, comparing its performance to ammonium acetate (AA). Three comparative criteria
were selected: (1) identification and peak quality of 34 standards following a metabolomics-specific
evaluation approach, (2) an intraday repeatability test with real samples and (3) performing two real
metabolomics fingerprints with the AF method to evaluate its inter-day repeatability. The AF method
showed not only higher ionization efficiency and signal-to-noise ratio but also better repeatability
and robustness than the AA approach. A tips and tricks section is then added, aiming at improving
method replicability for further users. In conclusion, ammonium fluoride as additive salt presents
several advantages and might be considered as a step forward in the application of robust HILIC
methods in metabolomics.
Origin | Publication funded by an institution |
---|