Berlin 2005 – wissenschaftliches Programm
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AKFH: Fachhochschulen
AKFH 1: Postersitzung: Forschung an Fachhochschulen
AKFH 1.7: Poster
Freitag, 4. März 2005, 14:00–15:30, Poster TU C
Detection of Manganese in Solution in Cavitation Bubbles using the LIBS Technique — •Sandra Koch1, Robert Court1, Walter Garen1, Walter Neu1, and Rainer Reuter2 — 1Fachhochschule Oldenburg/Ostfriesland/Wilhelmshaven, Photonics, Constantiaplatz 4, 26723 Emden, Germany — 2Carl von Ossietzky Universität Oldenburg, Institute of Physics, 26111 Oldenburg, Germany
Levels of dissolved manganese in water samples down to 80 ppb are measured using fluorescence spectroscopy. As optical emission spectroscopic methods tend to be insensitive due to strong quenching processes in liquids, using laser induced breakdown spectroscopy (LIBS) within a cavitation bubble overcomes this restriction. The output of a double pulsed Q-switched Nd:YAG laser system (wavelength @ 532 nm) is coupled into an optical fibre. The fibre guides the laser pulses to a silicon target immersed in a water sample contaminated with manganese. The cavitation process is initiated at the first laser pulse. At maximum bubble expansion, the second laser pulse ignites the plasma generated in the vapour/gas filled cavitation bubble. Fluorescence emission is collected by a further optical fibre in the bubble. Characteristic spectral line intensities of manganese are recorded and correlated to an internal calibration standard. Spectral analysis and data acquisition is carried out using an intensified optical multi-channel analyser.