Quantification evaluation of real time beryllium air monitoring using laser-induced breakdown spectroscopy
- Lawrence Livermore Lab., CA (United States)
- Inhalation Toxicology Research Institute, Albuquerque, NM (United States); and others
Beryllium particles in air can represent a significant inhalation health hazard. The OSHA permissible Exposure Limits for beryllium are 2 ug/m3 for Time-Weighted Average (TWA), 5 ug/m3 for Short Term Exposure Limit (STEL), and a maximum concentration (ceiling) of 25 ug/m3. The traditional methods of monitoring beryllium particles in air involve passing a known volume of air through a filter, chemically dissolving the collected material and determining the beryllium concentration of the solution using flame atomization atomic absorption spectrometry or inductively coupled plasma analysis. The process is time- consuming, requiring 6 to 8 hours. In this paper we discuss the use of laser-induced breakdown spectroscopy (LIBS) for real-time beryllium air monitoring. A small transportable Beryllium Air Monitor System based on the LIBS technique was developed at the Los Alamos National Laboratory. The instrument consists of a high power Q-switched Nd:YAG laser, optics for focusing the output of the laser, and systems for air sampling, emission detection, and instrument control. Beryllium particles in the air sample entering the ionization chamber of the instrument are vaporized and ionized. Light emitted from the plasma is used to identify and quantify the airborne beryllium concentrations. The instrument was tested in a series of calibration experiments using two different modes of operation. In the first mode, beryllium particles were deposited on filters, and laser sparks were formed at randomly selected locations on the filter surface and the average spectrum recorded. In the second mode, direct (real time) air monitoring was performed. Data were collected for several beryllium particle size ranges, and concentrations in air. If a particle is completely vaporized by the spark, one would expect the signal received from the LIBS instrument to be proportional to the mass of the particle.
- OSTI ID:
- 166555
- Report Number(s):
- CONF-9510126-; TRN: 95:008181-0046
- Resource Relation:
- Conference: Annual meeting of the American Association for Aerosol Research, Pittsburgh, PA (United States), 9-13 Oct 1995; Other Information: PBD: 1995; Related Information: Is Part Of American Association for Aerosol Research (AAAR) `95; PB: 464 p.
- Country of Publication:
- United States
- Language:
- English
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