Time-resolved surface temperature measurement of MALDI matrices under pulsed UV laser irradiation

Time-resolved examination of the surface temperature was performed for various MALDI matrices, irradiated by UV (gimel = 355 nm, tau = 5 ns) laser pulses. The temperature was measured by detecting the emitted blackbody radiation from the sample surface. The maximum surface temperature was observed to occur during the falling edge of the laser pulse, with a delay of 2 ns with respect to the laser pulse peak. Its value was found to depend on the kind of the matrix, the thickness of the sample and the laser fluence. For 2,5-dihydroxybenzoic acid, the most popular matrix, the peak temperature was found to be similar to850 and 1100 K at the lower (10 J/m(2)) and the higher (100 J/m(2)) fluences, respectively, used in this work.