TY - CONF A1 - Bierstedt, Andreas A1 - Bräkling, S. A1 - Rieger, J. A1 - Kersten, H. A1 - Glaus, Reto A1 - Gornushkin, Igor B. A1 - Riedel, Jens T1 - Development and characterization of an airborne laser-spark ion source for ambient desorption / ionization mass spectrometry N2 - A novel direct sampling ionization scheme for ambient mass spectrometry is presented. Desorption and ionization is achieved by a quasi-continuous laser induced plasma in air. Since there are no solid or liquid electrodes involved the ion source does not suffer from chemical interferences or fatigue originating from erosive burning or from electrode consumption. A laser plasma was ignited under ambient conditions in front of a modified TOF MS atmospheric pressure interface, using a high repetition rate DPSS laser operating at 532 nm and 26 kHz and an aspherical lens with a focal length of 8 mm. Emission spectroscopy (40-1100 nm) and time resolved studies on specific plasma parameters revealed insight into the physical and chemical plasma properties. Plasma ignition can be performed in rare gases and under ambient conditions. The hot plasma zone was kept at a certain distance from the sample region. Thus, effective collisional cooling seemed to prevent thermal fragmentation. Every single spark generates a shockwave, providing new reactive species, which expands concentrically from the hot region. Under ambient conditions primary charge carriers (ions and electrons) as well as VUV radiation initialize reaction cascades equivalent to other ambient ionization methods, such as DART or DBD. Mass spectra of polar/nonpolar hydrocarbons, sugars, pharmaceuticals and natural biomolecules in food were observed. Comprehensive emission spectroscopic measurements and time resolved electron current studies revealed insight into some plasma properties, such as the emitted high energetic radiation and the time evolution of the expanding plume. T2 - International Mass Spectrometry Conference 2016 CY - Toronto, ON, Canada DA - 20.08.2016 KW - laser-spark KW - laser-induced plasma KW - ambient mass spectrometry KW - emission spectroscopy PY - 2016 AN - OPUS4-37281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -