TY - JOUR A1 - Bierstedt, Andreas A1 - Panne, Ulrich A1 - Riedel, Jens T1 - Confinement and enhancement of an airborne atmospheric laser-induced plasma using an ultrasonic acoustic resonator T2 - Journal of analytical atomic spectrometry N2 - Optical elemental analysis in the gas phase typically relies on electrically driven plasmas. As an alternative approach, laser-induced plasmas (LIPs) have been suggested but have so far been only scarcely used. Here, a novel signal enhancement strategy for laser-based airborne plasma optical Emission spectroscopy for gas phase analytics is presented. In contrast to an electrically driven plasma, in the laser-induced analogue dynamic matter transport equilibrium builds up. The latter results in a rarefied density regime in the plasma core itself, surrounded by an area of compressed matter. The central rarefaction leads to a decrease in plasma intensity and analyte number density, both of which are detrimental for analytical purposes. Since the repetitive ignition of LIPs is a transient process, a restoration of the former gaseous medium by other dynamically equilibrated diffusion processes would be favourable. The presented combination of an airborne LIP and an ultrasonic acoustic resonator yields a fourfold signal enhancement while the Background contribution of ubiquitous air is at the same time effectively suppressed. Since the entire enhancement effect occurs without contact, no additional sources for abrasive sample contamination are introduced. PB - Royal Society of Chemistry CY - London KW - DPSS laser KW - Laser-induced plasma KW - High repetition rate KW - Ultrasonic acoustic resonator KW - Optical emission spectroscopy PY - 2018 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/43619 AN - OPUS4-43619 SN - 0267-9477 SN - 1364-5544 VL - 33 IS - 1 SP - 135 EP - 140 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany