Termopoli, VeronicaFamiglini, GiorgioVocale, PalmaMorini, Gian LucaPalma, PierangelaRocío-Bautista, PriscillaMansoor, SaeedPerry, SimonCappiello, Achille2025-01-312025-01-312020-090021-9673doi.org/10.1016/j.chroma.2020.461421https://hdl.handle.net/10953/4599Herein we present an efficient, column-switching method that relies on a custom-made T-union passive diffusion micromixer to assist water dilution and promote trap solute focusing of a high sample volume dissolved in pure organic solvent using a 0.075 mm i.d. nano-LC column. This method allows injecting 20 μL (or higher) of sample volume, speeding up the analysis time, with a 400-fold increase of the limits of quantitation for selected compounds. Five pesticides in different media were used as model compounds, and the analyses were carried out with a triple quadrupole mass spectrometer equipped with a Liquid Electron Ionization (LEI) LC-MS interface working in multiple reaction monitoring (MRM) mode. The system microfluidics were investigated using COMSOL modeling software. Robustness of the entire system was evaluated using a post-extraction addition soil extracts with limits of detection values spanning from 0.10 to 0.45 µg/L. Reproducible results in terms of peak area, peak shape, and retention times were achieved in soil matrix. Repeatability test on peak area variations were lower than 10%.engCC0 1.0 Universalhttp://creativecommons.org/publicdomain/zero/1.0/Ultra-large-volume injectionNano-LCLiquid electron ionizationmass spectrometryPesticidesMicrofluidicsinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess