Implementation of laser-induced breakdown spectroscopy as a continuous emissions monitor for toxic metals

Laser-induced breakdown spectroscopy (LIBS) has been considered for some ti me as a potential CEM method for toxic metals. Recently, improvements in sa mpling methodology and signal processing have allowed LIES to achieve detec tion limits below the proposed MACT limits for 5 out of 6 of the RCRA metal s. This paper discusses performance improved by nearly 2 orders of magnitud e of this in situ monitoring technique following implementation of conditio nal analysis. Results from trial burns at two incinerators and at a DoD con tained burn facility are highlighted. At the incinerators, implementation o f conditional analysis yielded much lower detection limits than previously reported using the LIBS technique. At the contained burn facility, reproduc ible, transient Pb measurements were recorded in real-time for concentratio n values that varied by more than two orders of magnitude. Method detection limits of between 2 and 100 mu g/dscm are reported for toxic metals Be, Cd , Cr, He, and Pb. (C) 2000 Elsevier Science Ltd. All rights reserved.