Portable Laser Induced Breakdown Spectrometer for Toxic Metals. Phase 1

摘要

A compact, portable laser induced breakdown spectroscopy (LIBS) system for thedetection of lead in soils and paints has been designed and evaluated in the laboratory. Fundamental studies of the temporal, spatial and spectral evolution of the LIB plasma have resulted in an optimized instrument. The system consists of a compact Nd:YAG laser operating at 1 Hz with a 21 mJ output at 1064 nanometers. The laser produces a reliable, reproducible breakdown on all materials that were investigated (soils, painted surfaces, metals, and air). Evaluations were conducted with an ungated portable spectrometer and a gated 0.5 m focal length laboratory spectrometer. The laboratory spectrometer which is gated and has a resolution similar to the proposed portable spectrometer (0.08 nm) yields excellent results. A limit of detection of Pb in paint was 60 micro-g/g for a single shot.