Coupling Liquid Chromatography to Orbitrap Isotope Ratio Mass Spectrometry: Overcoming Isotope Effects of Chromatography and Amount-Dependency by Peak Homogenization.

ABSTRACT: Electrospray ionization Orbitrap mass spectrometry (ESI-Orbitrap-MS) has recently proven to be a powerful tool for compound- and position-specific stable isotope analysis, targeting isotopologues of multiple elements (H, C, N, O, S) in polar analytes. However, studies have so far mainly focused on pure analyte solutions via direct infusion. Here, we present the online coupling of liquid chromatography (LC) to ESI-Orbitrap-MS for stable isotope analysis of sulfamethoxazole (SMX), a synthetic antimicrobial, used as a model compound. Our study explored the fidelity of isotope values with two strategies for capturing and broadening chromatographic peaks after LC. When capturing the target analyte in a capillary (0.7 mm inner diameter), peak shape was retained, resulting in systematic deviation

SUBMITTER: Canavan A 

PROVIDER: S-EPMC12809655 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature