Real-Time Broad Spectrum Characterization of Hazardous Mixed Waste by Membrane Introduction Mass Spectrometry
The goal of this project was to expand the range of chemical species that may be detected by membrane introduction mass spectrometry (MIMS) in environmental, and specifically in Mixed Waste, monitoring and characterization applications. Membrane introduction mass spectrometry (MIMS) functions as a near real-time monitor: there is little to no sample preparation and t analysis time is seconds to minutes. MIMS can be implemented as a flow injection technique, where samples, standards, and method blanks can be sequentially analyzed in a continuous fashion. The membrane acts as an interface between the sample (air or water) and the vacuum of the mass spectrometer. Transport of the analyte through the membrane occurs by the process of pervaporation. This process is described by adsorption to the outer surface of the membrane, diffusion through the membrane, and desorption from the inner membrane surface into a helium gas flow or into vacuum. The driving force for this work is the need for a rapid, sensitive, and broadly applicable tool for characterizing organic and metal-containing contaminants in a variety of DOE (and other) waste streams. In all characterization scenarios, a balance must be struck between evaluation of the hazards and their extent at a waste site, and the resources available for the overall mitigation of that risk. In the case of chemically, physically, and geometrically homogeneous waste, the situation is aided by the ability to reasonably assume that any sample collected is representative of the overall site constituents. However, few real environmental challenges are homogeneous. As a result, detailed sampling plans must be prepared, and chemical analyses must be performed on a number of samples in order to identify areas of contamination and assess further options. For many years, the chemical analysis part of this process has been accomplished by delivering the samples to a (typically) physically remote laboratory, where very detailed, and concomitantly expensive (both in time and money), procedures have been applied to the samples to determine their content; Environmental Protection Agency (EPA) methods for analyzing wastes for hazardous chemicals are 3 time-tested and very reliable. However, in many cases both time and resources may be conserved by being able to make survey analyses at the waste site to determine if any or all samples need to be exhaustively characterized by laboratory-based EPA analytical methods. A variety of groups worldwide are working on MIMS as a rapid screening tool for a variety of I applications; please see our review paper for a detailed overview of these efforts. Our primary innovations, developed during this project, have been the optimization of the ion source for environmental analyses and the study of chemically tailored pervaporation membranes for enhanced selectivity and sensitivity.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Management (EM) (US)
- OSTI ID:
- 828429
- Report Number(s):
- EMSP-59981; R&D Project: EMSP 59981; TRN: US200427%%377
- Resource Relation:
- Other Information: PBD: 31 Dec 2000
- Country of Publication:
- United States
- Language:
- English
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