Harmonization of FT-ICR-MS Instruments for Interoperable Multi-Laboratory Comprehensive Compositional Profiling

Abstract

Given the long hardware lifespan, fixed installation, and comparatively high investment required to procure them, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) instruments tend to have a long operational life. The field is constantly evolving with rapidly advancing instrumental developments, and FT-ICR research groups work with a range of instrument designs from different generations. Consequently, compositional spectra comparability between instruments is a critical concern in FT-ICR-MS, particularly due to the variability introduced by commonly used direct infusion methods. This study demonstrates interlaboratory comparability of FT-ICR-MS molecular profiles using a 12 T solariX with an Infinity Cell and a 7 T scimaX with a ParaCell, with closely matched sample introduction and ion guide systems. Using analytically challenging pet food samples, we achieved similar instrument performance metrics, including resolving power, mass error, feature count, signal-to-noise ratios, and m/z distribution. The improved field homogeneity and sensitivity of the ParaCell reduced ICR cell space-charge interferences, making specialized calibration methods beyond linear calibration obsolete. We observed up to 78% overlap in annotated signals of the spectra increasing to 95%, when higher-intensity features are considered. Relative abundances showed great similarity, despite sample-dependent fluctuations (median coefficient of variation 23.4% to 49.2% and 15.5% to 29.5%, respectively). Unsupervised multivariate analysis (PCA) revealed consistent sample profiles with no systematic bias. Our study demonstrates that with careful instrument adjustment, molecular profile comparability can be achieved, ensuring the continued relevance of extensive databases and large chemical data sets acquired in long-term and collaborative projects measured on different instrumentation.