Condensed Phase Membrane Introduction Mass Spectrometry (CP-MIMS) for Direct, Trace, On-Line Monitoring of Biomolecules and Environmental Contaminants in Complex Samples

摘要

Membrane introduction mass spectrometry (MIMS) uses a membrane to transfer analytes from a sample to a mass spectrometer. For most MIMS systems, hydrophobic analytes are transferred to a vacuum or gaseous acceptor phase (e.g. Helium), and are subsequently measured via EI-MS (e.g., modified GC/MS systems). Volatile/semivolatile analytes are readily measured, but for low volatility, polar and/or charged analytes the gaseous transfer step limits the technique. We present an improved version of a capillary hollow fibre membrane based MIMS system using a condensed acceptor phase (e.g. methanol) to facilitate the transfer of analytes from the membrane to an ESI-MS/MS system. We report parametric studies, potential applications for bioanalytical/environmental measurements, and a comparison with direct infusion ESI-MS for complex samples with high salt content (e.g. artificial urine).