1. Direct Coupling of Bio-SPME to Liquid Electron Ionization-MS/MS via a Modified Microfluidic Open Interface
- Author
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Veronica Termopoli, Janusz Pawliszyn, Priscilla Rocío-Bautista, Pierangela Palma, Giorgio Famiglini, Emir Nazdrajić, Achille Cappiello, Rocío-Bautista, P, Famiglini, G, Termopoli, V, Palma, P, Nazdrajić, E, Pawliszyn, J, and Cappiello, A
- Subjects
electron ionization ,SPME ,Microfluidics ,liquid−EI interface ,010402 general chemistry ,Mass spectrometry ,fentanyl ,01 natural sciences ,CHIM/01 - CHIMICA ANALITICA ,Structural Biology ,Desorption ,MOI ,Fiber ,matrix effect ,Spectroscopy ,Electron ionization ,Chromatography ,LEI ,liquid-EI interface ,Chemistry ,010401 analytical chemistry ,matrix effects ,Plasma ,nano-LC-MS/MS ,0104 chemical sciences ,Volumetric flow rate ,microfluidic open interface ,Direct coupling ,Research Article - Abstract
We present a modified microfluidic open interface (MOI) for the direct coupling of Bio-SPME to a liquid electron ionization-tandem mass spectrometry (LEI-MS/MS) system as a sensitive technique that can directly analyze biological samples without the need for sample cleanup or chromatographic separations as well as without measurable matrix effects (ME). We selected fentanyl as test compound. The method uses a C18 Bio-SPME fiber by direct immersion (DI) in urine and plasma and the subsequent quick desorption (1 min) in a flow-isolated volume (2.5 μL) filled with an internal standard−acetonitrile solution. The sample is then transferred to an EI source of a triple-quadrupole mass spectrometer via a LEI interface at a nanoscale flow rate. The desorption and analysis procedure requires less than 10 min. Up to 150 samples can be analyzed without observing a performance decline, with fentanyl quantitation at microgram-per-liter levels. The method workflow is extremely dependable, relatively fast, sustainable, and leads to reproducible results that enable the high-throughput screening of various biological samples.
- Published
- 2020