US EPA

1379832 

Technical Report 

Quantitative Analysis of the Detection Limits for Heavy Metal-Contaminated Soils by Laser-Induced Breakdown Spectroscopy 

Alexander, DR; Poulain, DE 

1997 

NTIS/02999083 

GRA and I 

GRA and I 

Laser-induced breakdown spectroscopy (LIBS) is a rapid remote measurement method for detection of metals in the environment. A major factor in the quantitative use of this technique involves the minimum detection limits under both laboratory and field operations. Research on limits of detection of heavy metals in different types of soils under various conditions using LIBS has been carried out under Contract DACA39-95-K-0053. Pulses from a Nd:YAG laser operating at 125 mJ at lambda = 1.06 micrometers are focused on sample surfaces to produce laser sparks (plasmas). Atomic emissions from the plasmas are recorded using an optical multichannel analyzer after delays of a few microseconds when interference from broad-band emissions is reduced. Research has been performed on the detection limits of arsenic, cadmium, chromium, mercury, lead, and zinc in soil matrices. Results are reported on the lower detection limits of these six elements in sand, silt, clay, and kaolin matrices. Detection limits are significantly lower for heavy metals in sand matrices than silt and clay matrices due to differences between surface and volume contamination. 

Yag lasers; *Spectroscopy; *Soils; *Laser applications; *Heavy metals; *Neodymium lasers; Emission; Metals; Measurement; Optical equipment; Quantitative analysis; Detection; Plasmas(Physics); Sand; Broadband; Interference; Clay; Mercury; Zinc; Cadmium; Sparks; Chromium; Soil pollution; Contamination; Analyzers; Arsenic; Atomic properties; Remote systems; Multichannel; Silt; Lead(Metal); Laser induced breakdown spectroscopy; Libs(Laser induced breakdown spectroscopy)