1. Microfluidic water-assisted trap focusing method for ultra-large volume injection in reversed-phase nano-liquid chromatography coupled to electron ionization tandem-mass spectrometry
- Author
-
Veronica Termopoli, Gian Luca Morini, Pierangela Palma, Mohammad Saeed, Achille Cappiello, Giorgio Famiglini, Pamela Vocale, Priscilla Rocío-Bautista, Simon J. Perry, Termopoli, V, Famiglini, G, Vocale, P, Morini, G, Palma, P, Rocío-Bautista, P, Saeed, M, Perry, S, Cappiello, A, Termopoli V., Famiglini G., Vocale P., Morini G.L., Palma P., Rocio-Bautista P., Saeed M., Perry S., and Cappiello A.
- Subjects
Acetonitriles ,Microfluidics ,Ultra-large-volume injection ,Micromixer ,Electrons ,010402 general chemistry ,Tandem mass spectrometry ,01 natural sciences ,Biochemistry ,Analytical Chemistry ,Matrix (chemical analysis) ,Diffusion ,CHIM/01 - CHIMICA ANALITICA ,Limit of Detection ,Tandem Mass Spectrometry ,Nano-LC ,Microfluidic devices, LC-MS, LEI-MS ,Pesticides ,Liquid electron ionization (LEI)-tandem mass spectrometry ,Electron ionization ,Detection limit ,Chromatography, Reverse-Phase ,Chromatography ,Chemistry ,010401 analytical chemistry ,Organic Chemistry ,Selected reaction monitoring ,Reproducibility of Results ,Water ,General Medicine ,Water-assisted trap focusing ,0104 chemical sciences ,Dilution ,Triple quadrupole mass spectrometer ,Pesticide ,Microfluidic ,Solvents ,Nanoparticles - Abstract
Herein 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%.
- Published
- 2020