Zeptomole-sensitivity electrospray ionization--Fourier transform ion cyclotron resonance mass spectrometry of proteins.

摘要: Methods are being developed for ultrasensitive protein characterization based upon electrospray ionization (ESI) with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The sensitivity of a FTICR spectrometer equipped an ESI source depends on the overall transmission, which combines probability ionization, transmission efficiency, and trapping in cell. Our developments implemented 3.5 tesla include introduction optimization newly designed electrodynamic funnel interface, improving beam characteristics quadrupole-electrostatic guide modification electrostatic guide. These provide detection limit approximately 30 zmol (∼18 000 molecules) proteins molecular weights ranging from 8 to 20 kDa.