Continuous-flow liquid microjunction surface sampling probe connected on-line with high-performance liquid chromatography/mass spectrometry for spatially resolved analysis of small molecules and proteins.

摘要: Rationale A continuous-flow liquid microjunction surface sampling probe extracts soluble material from surfaces for direct ionization and detection by mass spectrometry. Demonstrated here is the on-line coupling of such a with high-performance chromatography/mass spectrometry (HPLC/MS) enabling extraction, separation small molecules proteins in spatially resolved (~0.5 mm diameter spots) manner. Methods was connected to six-port, two-position valve extract collection injection an HPLC column. QTRAP® 5500 hybrid triple quadrupole linear ion trap equipped Turbo V™ source operated positive electrospray (ESI) mode used all experiments. The system operation tested propranolol associated metabolites drug dosed tissues, caffeine coffee bean, cocaine paper currency, dried sheep blood spots on paper. Results Confirmed tissue were parent two different hydroxypropranolol glucuronides. spectrometric response these compounds locations liver showed increase increasing extraction time (5, 20 40 s). For detection/identification extracted spots, major protein peaks dominated chromatogram could be correlated expected masses hemoglobin α β chains. Conclusions Spatially sampling, separation, can accomplished using coupled HPLC/MS detection.