Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1021/acs.analchem.0c04426
Document author version
Title (Primary) Online counter gradient LC-FT-ICR-MS enables detection of highly polar natural organic matter fractions
Author Han, L.; Kaesler, J.; Peng, C.; Reemtsma, T.; Lechtenfeld, O.J. ORCID logo
Source Titel Analytical Chemistry
Year 2021
Department ANA
Volume 93
Issue 3
Page From 1740
Page To 1748
Language englisch
Topic T9 Healthy Planet
UFZ wide themes ProVIS
Abstract Natural organic matter (NOM) is a highly complex mixture of natural organic molecules. The recent developments in NOM molecular characterization methods have shown that ESI-FT-ICR hyphenated with liquid chromatography (LC) is a promising approach to also obtain chemical information (such as polarity and molecular size) about NOM molecules. However, due to changing solvent composition during gradient elution in LC-FT-ICR-MS, ionization conditions also change throughout the chromatographic separation process. In this study, we applied a post-LC column counter gradient (CG) to ensure stable solvent conditions for transient ESI-MS signals. Suwanee River Fulvic Acid (SRFA) standard and a peat pore water were used as representative dissolved NOM samples for method development and validation. Our results show that in polar NOM fractions (which elute with <50% methanol) the TIC intensity and number of assigned molecular formulas were increased by 48% and 20%, as compared to the standard gradient (SG) method. Further application of a Q-isolation and selective ion accumulation for low abundance fractions revealed over 3 times more molecular formulas (especially for CHNO, CHOS, CHNOS formula classes) than in full scan mode. The number of detected highly polar NOM compounds (with elemental ratios H/C < 1, O/C > 0.6) were more than 20 times larger for CG-LC mode as compared to direct infusion (DI) (5715 vs 266 MF). We conclude that the application of a postcolumn counter gradient in LC-FT-ICR-MS analyses of NOM offers novel insight into the most polar fractions of NOM which are inaccessible in conventional DI measurements.
Persistent UFZ Identifier
Han, L., Kaesler, J., Peng, C., Reemtsma, T., Lechtenfeld, O.J. (2021):
Online counter gradient LC-FT-ICR-MS enables detection of highly polar natural organic matter fractions
Anal. Chem. 93 (3), 1740 - 1748 10.1021/acs.analchem.0c04426