Two designs are leading to online, IR matrix-assisted laser desorption/ionization mass spectroscopy of biomolecules. Kermit K. Murray, an assistant professor of chemistry at Emory University in Atlanta, and colleagues from Odense University in Denmark added a rotating ball inlet to a UV matrix-assisted laser desorption/ionization mass spectrometer, eliminating the clogging associated with an earlier, frit-based online technique.

Murray has developed an IR system, but its 3-µm Nd:YAG-pumped optical parametric oscillator from Continuum of Santa Clara, Calif., suffered damage to a KTP crystal before the demonstration of the ball inlet. He said the researchers plan to investigate the use of ice as a matrix in an infrared system with the new inlet design. The IR version of this technique offers better ablation of a sample and the choice of more liquid matrices.