Abstract
The rapidly growing interest in matrix-assisted laser desorption-ionization
(MALDI) mass spectrometry (MS) using infrared lasers is rooted in the possibility
of mass-analyzing proteins and nucleotides in pH-neutral matrix materials.
We have used a picosecond tunable mid-infrared free-electron laser to explore
the mechanisms of infrared desorption and ionization of both large and
small biological molecules from a solid and liquid matrix materials.
The mass spectra have excellent resolution, often with less matrix background
than more conventional measurements; in addition, the infrared laser pulses
seem to produce a great many more multiply charged ion species than one
might first expect. We also find that the conventional model of infrared
MALDI for nanosecond laser pulses does not hold up well, since ion desorption
times appear to be governed by laser intensity and not fluence. The
apparently high efficiency of picosecond vs nanosecond pulses appears to
be well grounded from other studies made of desorption, ionization and
ablation mechanisms in molecular crystals in this wavelength range.
The potential implications of these findings for the future of mass spectroscopy
with mid-infrared lasers will be discussed.
Background
Richard Haglund was educated at Wesleyan University and the University
of North Carolina at Chapel Hill where he completed a Ph.D. in nuclear
structure physics using spin-polarized beams. After postdoctoral
research at the Los Alamos National Laboratory, he joined the staff of
a laser-fusion project there, serving eventually as both section and group
leader. In 1984, he moved to Vanderbilt University, where he pursues
research on laser-induced desorption and ablation with pico- and femtosecond
mid-infrared lasers, ultrafast nonlinear optics in metal quantum dots,
and laser-assisted synthesis of nanostructured materials. He is a
member of the Committee on Atomic, Molecular and Optical Sciences of the
National Research Council, chaired the Gordon Research Conference on "Laser
Interactions with Materials" in 1998, and was an Alexander von Humboldt
Fellow in 1982-83.
Meeting details
| Date: | Thursday | April 15, 1999 |
| Time: | 6:00 pm | Social hour, registration (no-host cocktails) |
| 7:00 pm | Dinner ($25 includes wine) | |
| 8:15 pm | Lecture (free, no reservations required) | |
| Dinner: | Szechuen Spicy Prawns, Ming's Beef with Broccoli, Lichee Sweet &
Sour Pork, Sauteed Water Chestnuts w/ Fresh Sno Peas, all served with Yang Chow Fried Rice. |
|
| includes | salad, desert, wine, coffee | |
| Cost: | $25.00 | Reservations required (by 12:00 noon Monday, April 12, 1999) for dinner |
| $10.00 | Students only |
The San Francisco Bay Area Mass Spectrometry discussion group was formed
in 1980 to provide a regular gathering for people interested in mass spectrometry
and allied topics. BAMS currently has a membership of about 280 individual
and 20 corporate members, and meets 8-10 times per year for a midweek dinner
and lecture. Meetings attract between 30 and 90 people, and are held
at a restaurant or hotel in the bay area convenient for our speaker.
We usually convene at 6:00pm for cocktails, dinner at 7:00pm, and lecture
at 8:15pm.
If you have suggestions for a meeting topic, or know of a prominent
mass spectroscopist who will be visiting the bay area, please contact our
program chair.
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BAMS has been fortunate to have had many excellent
speakers in our short history.
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me at hugh-gregg@llnl.gov
Last update: 4/7/99.