Employing target modifications for the investigation of liquid infrared matrix-assisted laser desorption/ionization mass spectrometry.

We present a new target modification for commercial ion sources to facilitate the use of liquid matrices such as glycerol and lactic acid in infrared matrix-assisted laser desorption/ionization (IR-MALDI). Benefits of this modification include increased sensitivity compared with the unmodified commercial target, mass resolution comparable to the best achievable with conventional IR-MALDI or UV-MALDI, and decreased sample volatility leading to an analysis time extended up to fivefold compared with using conventional target designs (up to 1 hour using volumes of only 250 nL).