Laser-Induced Breakdown Spectroscopy on Solution Samples Using Surface Excitation

Laser-induced breakdown spectroscopy (LIBS) is a spectroscopic technique where output from a pulsed laser is focused onto a target in order to create an intense plasma. The optical emission is characteristic of the elements in the focal volume and can be used for elemental analysis. Research on the detection of nickel in solution in addition to solvent detection of CCl4, CHCl3, C2Cl4, and C2HCl3 has been performed. Breakdown was formed at the sample surface via a Q-switched Nd:YAG laser. Initially, operation of the laser was at 1064 nm/ repetition rate of 5 Hz. Experiments were also performed using the third harmonic (355 nm)/repetition rate of 20 Hz. Pulse energy was maintained at 60 MJ. The spark light was spectrally resolved and detected by a time-gated photodiode array. A 50 microsecond gate width/8 microsecond time delay gave detection limits of 56.1 mg/l for nickel in solution. In the UV, a 10 microsecond gate width/3 microsecond time delay lowered detection limits down to 29.4 mg/l. Concentrations spanned from 50 to 1000 mg/l. Using UV excitation (10 microsecond gate width/l microsecond time delay), saturated solvent solutions as high as 7.71 g/l were not detectable.Air Force Inst of Tech Wright-Patterson AFB OH is the author of 'Laser-Induced Breakdown Spectroscopy on Solution Samples Using Surface Excitation', published 1996 under ISBN 9781423573104 and ISBN 1423573102.