Optical detection methods for mass spectrometry of macroions.
Detection of macroions has been a challenge in the field of mass spectrometry. Conventional ionization-based detectors, relying on production and multiplication of secondary electrons, are restricted to detection for charged particles of m/z < 1 x 10(6). While both energy-sensitive and charge-sensitive detectors have been developed recently to overcome the limitation, they are not yet in common use. Photon-sensitive detectors are suggested to be an alternative, with which detection of macroions (or charged particles) by either elastic light scattering (ELS) or laser-induced fluorescence (LIF) has been possible. In this article, we provide a critical review on the developments of novel optical detection methods for mass spectrometry of macroions, including both micron-sized and nano-sized synthetic polymers as well as high-mass biomolecules. Design and development of new spectrometers making possible observations of the mass spectra of macroions with sizes in the range of 10-10(3) nm or masses in the range of 1-10(6) MDa are illustrated. The potential and promise of this optical approach toward macroion detection with high efficiency are discussed in practical aspects.
Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, Taiwan 106.
Wen-Ping
WP
Peng
Yong
Y
Cai
Huan-Cheng
HC
Chang
D004867:Equipment Design; D007477:Ions / Q000032:analysis*; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods*; D008832:Microchemistry / Q000379:methods*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D043942:Nanotubes / Q000032:analysis*; D055095:Optics and Photonics; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
D007477:Ions