Infrared multiphoton dissociation with a hollow fiber waveguide.
A novel scheme for performing infrared multiphoton dissociation (IRMPD) is presented in which a hollow fiber waveguide (HFWG) is used to transmit IR radiation into the ion storage region of a mass spectrometer. Efficient dissociation of oligonucleotide and protein ions is demonstrated on an ESI-FTICR instrument in which IRMPD is performed in the external ion reservoir and on a quadrupole ion trap. Using a simple optical scheme consisting of a single focusing lens and an x, y translator, the 10.6-microm IR laser beam, initially 3.5 mm in diameter, is focused into the vacuum-sealed HFWG. The small internal diameter and the high transfer efficiency of the waveguide allow IR radiation of high power density to be employed for IRMPD. In studies performed on a quadrupole ion trap, a 500-microm-i.d. waveguide was used as a medium to transmit IR radiation directly through a 700-microm orifice in the ring electrode. Efficient IRMPD of both a 12-mer oligonucleotide and the protein melittin were performed at laser powers of 0.5 and 3.2 W, respectively.
Ibis Therapeutics, Isis Pharmaceuticals, 2292 Faraday Avenue, Carlsbad, California 92008, USA.
Jared J
JJ
Drader
James C
JC
Hannis
Steven A
SA
Hofstadler
D000818:Animals; D001483:Base Sequence; D001514:Bee Venoms / Q000737:chemistry; D004566:Electrodes; D007259:Infrared Rays; D007477:Ions; D007834:Lasers; D008555:Melitten / Q000032:analysis / Q000737:chemistry; D009841:Oligonucleotides / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D017785:Photons; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation* / Q000379:methods*
D001514:Bee Venoms; D007477:Ions; D009841:Oligonucleotides; D008555:Melitten