British Columbia Mine Reclamation Symposia

Development of a field-portable x-ray fluorescence system for on-site hazardous waste screening Raab, Gregory Alan; Faber, Marianne L.; Simon, S. J.; Eccles, Lawrence A. 1989

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th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  137  DEVELOPMENT OF A FIELD-PORTABLE X-RAY FLUORESCENCE SYSTEM FOR ON-SITE HAZARDOUS WASTE SCREENING  by G. A. Raab, M. L. Faber, S. J. Simon, Lockheed Engineering and Management Services Company, Inc. Las Vegas, Nevada 89119 and L. A. Eccles Advanced Monitoring Systems Division Environmental Monitoring Systems Laboratory Las Vegas, Nevada 89193  Contract Number 68-03-3249 Project Officer L. A. Eccles Advanced Monitoring Systems Division Environmental Monitoring Systems Laboratory Las Vegas, Nevada 89193  ENVIRONMENTAL MONITORING SYSTEMS LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT O.S. ENVIRONMENTAL PROTECTION AGENCY LAS VEGAS, NEVADA 89193  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  138  CONTENTS  Notice  Abstract  ........................................................  ...............................................  List of Figures ................................................. List of Tables ................................................. SECTION  1  Introduction ..................................... Background Information ..........................  Data Quality Considerations ........................ Principles of X-Ray Fluorescence. ............... .... Field Application ............. ...................  2  3 4  Project Objectives ............................. Primary Objectives .......................... Specific Objectives .............. . ......... Evaluation of Field-Portable Systems .......... . ...... System Development ................................ Evaluation of Prototype and Commercial Instruments. . . Standard Reference Sample Development ............. Software Evaluation and Development .............. Field Method Development......................... Incorporation of Telemetry System ................ Technology Transfer ........................... Project Report ................................ Development of CLP XRF Laboratory Method ................. Commercializing the Federally Funded Prototype............  Future Applications ............................... References .......................................  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  139  NOTICE The information in this document has been funded wholly or in part by the United States Environmental Protection Agency under contract 6803-3249 to Lockheed-BMSCO. It has been subject to the Agency's peer and administrative review, and it has been approved for publication as an BPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  140  LIST OP FIGURES FIGURE  1 Comparison of general requirements (all parameters, all methods) and specific requirements (inorganic constituents, XRF method) for analytical data quality................... 2 Excitation of a traditional Bohr atom to produce characteristic radiation. A: Incident photon bombards sample, produces photoelectron, and creates vacancy in inner shell of atom. B: Outer electron seeks stability and falls into vacancy, producing characteristic radiation (fluorescence). . . 3 Traditional pathway for sampling and analysis. Elapsed time from sample collection to receipt of data by site manager is 21 days ............................................ 4 Hazardous waste site screening with field-portable XRF methodology provides data acquisition, transfer, processsing, and plotting capability in real time, on site ........ 5 Future capability for field-portable XRF screening and analysis of inorganic contamimmts at Superfund sites ...... 6 Work station for on-site processing of XRF data ........... 7 Simulation of a coordinate and concentration map generated by an idealized field-portable XRF system. Zinc values (in parts per million) are plotted above the location symbols, and lead values (in parts per million) are plotted below the symbols .................................... 8 Simulation of concentration isopleth maps generated by the field-portable XRF system. A: Original concentrations of lead (in parts per million), corresponding to lead values shown in Figure 7. B: Concentrations recorded after firstpass site 'cleanup. C: Concentrations recorded after secondpass site cleanup. Screened areas show concentrations above remedial action level .................................  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  141  ABSTRACT  Identifying, characterizing, and monitoring the large number of hazardous waste sites in the United States is a difficult, complex task. Development of a field-portable x-ray fluorescence system and of the associated sampling and analytical protocols may simplify one aspect of this task: the screening of hazardous waste sites for inorganic contaminants. Ve are investigating the capabilities of commercial systems that are in the design, prototype, and commercial stages of development, and we are providing input into the development of a federally funded prototype. By using off-the-shelf and prototype instruments in the field, we are able to compare their capabilities, refine instrument performance requirements, develop standard reference samples and standardized field methodology, and provide real-world assistance to regional personnel, A planned market survey will help us identify the range of usefulness of the technique with the aim of advancing the federally funded prototype to production through a contract with a commercial manufacturer. We have already produced tangible results in many of these areas; additional funding must be approved to advance some aspects of the project. In tandem with the effort to develop this technology for use in sampling soils at hazardous waste sites, we are exploring the applicability of the technique to identifying contaminants in wastewater, ground water, living plant tissues, and building materials; and to determining the length of time that must pass before zeolite-amended contaminated soils Can safely be vegetated.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  142  LIST OP TABLES TABLE  PAGE  1  Framework Activities for the Field Portable X-Ray Fluorescence Project ....................................... 14  2  Availability of Field-Portable X-Ray Fluorescence Systems . . . 18  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  147 please note - the gap of four pages is in the original camera-ready copy and is not a product of digitalization - Mainstay Computing -  SECTION 1  INTRODUCTION  BACKGROUND INFORMATION Identifying, characterizing, and monitoring the large number of hazardous waste sites in the United States is a formidable task. The difficulty of the task is compounded by (1) the large number of organic and inorganic contaminants that may be present, (2) the complexity and limitations of the analytical methods used, and (3) the ultimate application of the data, i.e., litigation and regulatory enforcement, exposure assessment, or site screening. The Environmental Monitoring Systems Laboratory, Las Vegas, Nevada (EMSL-LV), with major assistance from Lockheed Engineering and Management Services Company, Inc. (Lockheed-EMSCO) has recently initiated a project designed to expedite one aspect of the site characterization and monitoring process: the screening of hazardous waste sites for inorganic contaminants. Project participants are developing, testing, and employing field-portable analytical instruments that apply the x-ray fluorescence (XRF) technique. In contrast to traditional laboratory atomic absorption spectroscopy (AAS) and inductively coupled plasma atomic emission spectroscopy (ICP), a fully portable XRF system can analyze soil samples on site. This capability allows the on-site analyst to determine immediately the location and constituents of the contamination as well as the necessity for additional remedial work beyond the screening level.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  148  DATA QUALITY CONSIDERATIONS The suitability of data for different remedial investigation (RI) and feasibility study (FS) applications is of major concern. Suitability is determined by data quality, which, in turn, is expressed as a measure of the accuracy, precision, and sensitivity of the analytical method employed. To guide site researchers and workers in evaluating the potential quality of the data they collect and interpret, EPA has defined general requirements for the types of analytical data and the levels of analytical data quality that are suitable for different RI and PS applications. EPA (1987) specifies five levels of analytical data quality (see Pig. 1). Level I is applicable to field screening or analysis by using portable instruments. Level I data may not necessarily be quantitative or compound-specific, but results often can be produced in real time-Level II data are obtained by using more sophisticated portable analytical instruments. The instruments may be incorporated into an on-site mobile laboratory, and results can be obtained in real time or within a few hours. The quality of the data may range widely; the use of standards, appropriate calibration technique», and sufficient training of operators and analysts are some major determining factors. Level III data are obtained from analyses performed at an off-site analytical laboratory. The analytical laboratory will use quality assurance procedures that follow requirements for the higher analytical levels (IV and V), but the laboratory may not be one recognized by the EPA Contract Laboratory Program (CLP). Level IV analyses are those routine analyses performed in an off-site CLP laboratory. All analyses are conducted under strict adherence to CLP procedures; quality assurance and quality control protocols are rigorous. Level V analyses are nonstandard analyses or methods that must be employed to meet unusual or site-specific needs. The analytical laboratory may or may not be CLP-approved. Generally, Level I and II analyses can provide data on site, whereas Levels III, IV, and V concern data produced at an offsite analytical laboratory and over a longer time frame. For the application described in this report, specific analytical data quality requirements for XRF analysis of inorganic constituents have been derived from the EPA general requirements and from previously published literature on XRF analysis of inorganic constituents (Raab et al., 1987). A comparison of the EPA general analytical requirements and the derived XRF-specific requirements is given in Figure 1. The EPA general requirements for level IV and V analyses correspond to the XRF-specific requirements for analytical degree 1: data of very high quality, suitable for litigatory, regulatory, and remediation applications. Degree 1 data are obtained by off-site laboratory analysis of aqueous samples. EPA general requirements for level II and  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  149  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  150  III analyses correspond to XRP-specific requirements for analytical degree 2: data of moderately high quality, suitable for evaluation and assessment of average pollutant exposure to humans and animals. Degree 2 data are obtained by off-site laboratory analysis of aqueous or solid samples. EPA general requirements for level I analyses correspond to XRP-specific requirements for analytical degree 3: screening, preliminary evaluation, and on-site decision making. It is analytical degree 3 (EPA analytical Level I), for which data are obtained by field laboratory and in situ analyses, that is moat applicable to the data derived by using the field-portable XRF analyses procedures described in this report. PRINCIPLES OP X-RAY FLUORESCENCE Traditionally, one application of energy-dispersive XRF has been as a laboratory method for detecting and quantifying the elements present in soil samples. The method works on the principle that incident photons bombard the sample to produce fluorescence. The incident photon impinges on the electron clouds in the atom. Among other events, this process creates vacancies in one or more of the inner shells (see Fig. 2a). Vacancies occur in the K shell and sometimes in the L shell. The vacancies cause an instability within the atom, below the outer-shell electrons. As the outer electrons seek stability by falling into the vacancies in an inner shell, the atom emits energy as an x-ray photon (Pig. 2b). The emitted energy (fluorescence) is characteristic of the atom in which it was produced and is equal to the difference between the higher energy state and the lower energy state. Most elements under the photon bombardment fluoresce simultaneously to produce a spectrum of characteristic radiation. It is this spectrum that the detector senses and counts. FIELD APPLICATION The field-portable XRF system is anticipated to be an effective, on-site complement to the traditional CLP-approved wet chemistry methods such as ICP and AAS, as well as to the laboratory XRP methods. The field-portable XRF method packages traditional XRP capability in an instrument that can be carried by one person and that can be operated in the field by a two-person team. The portability of the instrument has major advantages: During an initial (screening) visit to a hazardous waste site, project personnel can analyze soil samples in situ and review the computer-processed results immediately, identify and verify the areal distribution of contamination, and determine whether contamination levels are high enough to warrant further remedial work. The application of such a field-portable system for  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  151  Figure 2. Excitation of a traditional Bohr atom to produce characteristic radiation. A: Incident photon bombards sample, produces photoelectron, and creates vacancy in inner shell of atom. B: Outer electron seeks stability and falls into vacancy, producing characteristic radiation (fluorescence).  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  152  hazardous waste site investigations can net an overall decrease in the time and cost of analyses for the metals detected because it can provide data in real time, on site. During the initial screening of a hazardous waste site, sample data produced by the field-portable XRF system can be processed immediately by a computer. The field crew then can use the processed data to: • • • •  identify the contaminated areas restrict the investigation to these areas determine approximate contaminant concentrations and choose samples on the basis of those determinations determine whether or not investigation or remediation beyond the screening level is necessary  For exposure assessment (Levels II and III, Degree 2) analysis, samples must undergo more rigorous sample preparation than is required for screening (Level I, Degree 3) analysis. If field-portable XRF is used during screening, contaminated areas and areas that register as "background" (noncontaminated) are identified before the Degree 2 analysis. As a result, samples collected from noncontaminated areas can be excluded from the rigorous preparation required for Degree 2 analysis. Consequently, the intensified effort can be restricted to the known areas of contamination, and the number of samples that must be analyzed will be reduced. PROJRCT OBJECTIVES Primary Objective Fielding a fully developed system at Superfund sites is the primary goal of the field-portable XRF program. Traditionally, samples have been collected at the site, packaged, and shipped via overnight courier to a CLP laboratory for analysis (see Fig. 3). This process routinely takes 21 days to complete. The field-portable XRF methodology provides significant time and cost savings over the traditional pathway for sampling and analysis. We can now acquire, transfer, process (via computer) and plot data on site (see Fig. 4). Our ultimate goal is to equip a two-person field team with an instrument that will measure the concentrations of the inorganic contaminants and transmit the data, including the coordinates of the in situ analysis, to a portable computer at a work station near the enclosed area under study (see figs. 5 and 6.)  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  153  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  154  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  155  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  156  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  157  As the crew traverses the site and collects in situ measurements, the data base will expand. As the crew finishes the traverse and leaves the site, the computer will process the data, generate a coordinate and concentration map (Pig. 7), and generate concentration isopleth (contour) maps of the elements on the site (Fig. 8). The site will be mapped for each element, and the data will be provided to the site manager. As the remedial action progresses, the site manager can have the site screened to test the effectiveness of the remediation. If contaminants are present in concentrations sufficient to warrant further remedial work, the site manager can continue to use the procedures to monitor concentration levels until they are below the designated action levels (see Pig. 8). The final map can also be used to verify that the contractor has completed the soil removal or soil amendment task.  Specific Objectives The specific objectives of the field-portable XRP project are to evaluate prototype and commercially available field-portable XRP systems through field and laboratory testing, to investigate the applicability of XRF and field-portable XRF as alternatives to CLP analytical methods now in use for hazardous waste site studies, to encourage commercial production of the federally funded prototype instrument, and to define and investigate other uses of the field-portable XRF technique. The framework activities supporting these objectives are listed in Table 1. Tasks related to the application of XRP to hazardous waste site screening are described in Section 2, and tasks related to other applications are described in Section 3.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  158  ‘  Figure 7.  Simulation of a coordinate and concentration map generated by an idealized field-portable XRF system. Zinc values (in parts per million) are plotted above the location symbols, and lead values fin parts per million) are plotted below the symbols.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  159  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  160  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  161  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  162  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  163  SECTION 2 EVALUATION OF FIELD PORTABLE SYSTEMS SYSTEM DEVELOPMENT Evaluation of Prototype and Commerical Instruments A major framework activity within this project is to evaluate prototype and commercially available field-portable XRF systems and their applicability to hazardous waste screenings. We are surveying companies that manufacture XRF equipment, and we are compiling information on companies that (1) make field-portable systems, (2) have technology for field-portable systems available or under development, or (3) are interested in commercial development of a federally funded prototype. Survey results for information collected to date are summarized in Table 2. After the survey has been completed, EMSL-LV will request that interested companies make their instruments available for evaluation. For each XRF system, it is possible that EMSL-LV will arrange for the instrument manufacturer to supply the system for evaluation at EMSL-LV, that Lockheed-EMSCO will lease the system, or that selected standards will be sent to the manufacturer for comparative analyses. The evaluation will consist of analyzing soil samples for all 24 metals that must be analyzed under CLP requirements. We will use the prototype and commercially available field-portable XRF instruments to analyze soil samples of known composition (standards and spiked standards), and we will validate these analyses by using CLP analytical methods (AAS and ICP). For each instrument, we will evaluate minimum detection limits, analytical range, precision and accuracy of data, sophistication of interference corrections, portability, and operation of the external probe that permits in situ measurement. The analyses will follow CLP protocols because these protocols require rigorous, well-documented quality assurance and quality control methods and because CLP data have been used successfully in litigation. Evaluation will deviate from the CLP protocols only in the method of sample preparation: Because XRF analysis measures the total elemental concentration, the acid-leach sample preparation procedure specified for the CLP methods is inadequate for comparison. Therefore, the preparation method we will use in the field-portable XRF evaluation will require total dissolution of the sample, but will demand the same  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  164  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  165  rigor as the CLP digestion procedure. After the sample is in solution, the instrumental analysis will be conducted according to the CLP requirements for ICP or AAS. Standard Reference Sample Development To date, there has not been a demand for field-portable XRP systems in hazardous vaste screening, hence standards for use in establishing calibration curves are not commercially available. To provide appropriate calibration standards for the instrument evaluation, we will prepare preliminary standards for each site analyzed. We will verify each set of standards by laboratory XRF and by ICP or AAS. For each of the 23 metals that can be detected by XRF, we will also prepare soil standards spiked at 5 and 10 times the instrumental detection limits. These spiked standards will be used to test the precision, accuracy, and instrumental detection limit for each fieldportable XRF system. We will split the spiked soils, then pelletize one split of each sample to qualify them as standards. We will analyze each pellet (standard) by XRF, analyze every tenth pellet by ICP, and evaluate the recoveries. We also intend to develop pure-element standards and multielement calibration standards in a variety of concentration ranges. Once developed, these standards can be presented to the National Bureau of Standards (NBS) for certification as standard reference materials (SRMs). NBS takes as long as 2 years to certify SRMs, thus standards could be available to industry within that time frame. Software Evaluation and Development Software requirements for a field-portable XRF system that would meet hazardous waste screening needs are three-fold: machine-language software, geostatistical software, and contouring software. Criss Software, Inc., has developed prototype machine-language software designed to optimize peak deconvolution. BMSL-LV will evaluate the prototype software as well as commercially available software. We have acquired the geostatistics software package under development by B. Englund (BPA EMSL-LV) and A. Sparks (Computer Science Corporation). When completed, the Englund-Sparks system will meet all specifications for the XRF field work application except that it will not supply non-kriging interpolators. Completion of the geostatistics  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  166  software is expected by December 1988; however, review copies of the software are now available from the authors. EMSL-LV hag purchased a graphics package (CPS/PC, produced by Radian Corporation), for use in conjunction with the Englund-Sparks geostatistics package. CPS/PC would supply the non-kriging interpolators and would provide versatile capabilities for generating report-quality maps and graphics. The Englund-Sparks package could be modified to produce external grid files in the CPS/PC format; CPS/PC then would be used to perform mapping and contouring. Furthermore, CPS/PC has an interface system which would enable a graphic output file to be enhanced with an automatic drafting system (AUTOCAD, procued by Autodesk, Inc.). The coordinate and concentration map in Figure 3 and the concentration isopleth maps in Figure 4 are examples of the CPS/PC software capability. Field Method Development We have developed a preliminary method for preparing samples in the field. As the project progresses, we will expand the method to include analytical protocols, field test the method, revise it, update and submit it for peer review.  Incorporation of Telemetry System Martin Marietta, under contract to the Oak Ridge National Laboratory, has built a telemetry system that allows a hazardous waste site field analyst to identify surveyor's coordinates for each area analyzed. These coordinates, along with the concentrations of the elements identified, are transmitted to a PC at a nearby field station. The computer at the field station then uses the geostatiatical software to krig the data. The data then are mapped by the CPS/PC contouring software. During a recent field excursion, we used an X-Met 840 (see Table 2) to screen a Superfund site. The total time for screening and data logging was 6 1/2 hours; 5 of those hours were dedicated to identifying in situ analysis site coordinates. Berven et al. (1987) suggest that 25 percent of any surveying process is dedicated to data recording and formatting. For field-portable XRF applications, this time expenditure could be eliminated by implementing the telemetry system.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  167  Technology Transfer Through the EMSL-LV Technical Support Center for Monitoring and Site Characterization, we will make available to the regions all the data pertaining to the evaluation of the field-portable XRP system and equipment. It is anticipated that EMSL-LV will also provide a training course for regional personnel on how to use the equipment and how to interpret the data. In order to display and demonstrate the capabilities of this technology at as many locations as possible, we have built a mobile field station that can be taken to the regional EPA offices, (Fig. 6). We will also provide logistical support for designated Superfund demonstrations. To date, we have conducted three site demonstrations with Region X and have aided Region VI in a site demonstration. The following examples of site applications suggest the versatility of the technology: 1. EMSL-LV designed a field analysis method for a site demonstration of X-ray fluorescence systems. This method included collecting surface soil samples, preparing and analyzing them in the field, returning them to the laboratory, analyzing them with the ICP under CLP constraints, and comparing the XRP results with those from the ICP. Sampling was performed by an EPA-designated contractor. Kevex Corporation supplied an analyst and a Delta XRF Analyst System (see Table 2). Measurements taken at the site with this system were analyzed immediately to determine the concentration of specified metals. Each sample was placed in a polyurethene weighing boat, then dried in a microwave oven. A subsample was taken, placed in a standard XRP sample cup, covered with a polypropylene film, and presented to the XRP system. After the analysis was complete, the subsample was returned to the original sample bottle and the bottle was capped. This method allowed for rapid, degree 2 analysis and evaluation. This Superfund site is under remediation that is almost completed. Because high concentrations of the contaminants should have been removed, we did not expect to find high values for the samples we collected from this site; however, 15 samples exhibited concentrations between 10,000 and 71,500 mg/kg zinc. We collected samples outside the site and assumed them to represent "normal" background conditions. The background concentration for zinc was about 166 mg/kg. For chromium, 21 samples yielded values between 1,000 mg/kg and 15,700 mg/kg; background concentration was about 55 mg/kg. For lead, 29 samples yielded values between 1000 mg/kg and 12,600 mg/kg; background concentration was about 93 mg/kg. Values for cadmium, copper, and nickel did not appear to be nearly as high. In addition, the qualitative scans showed the. high presence of zirconium in many samples.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  168  On the basis of the data collected, our minimum detection limits were calculated by a software program as follows: chromium, 5.3 mg/kg; nickel, 13-1 mg/kg; copper, U.6 mg/kg; zinc, 9-2 mg/kg; lead, 6.5 mg/kg; and cadmium, 6.3 mg/kg. The detection limits are affected by the matrix and the counting statistics. The values reported here are baaed on a calibration curve derived from the original site screening data. This calibration curve represents data from extraction procedures similar to CLP analyses rather than a total analysis, as is usually the case in XRF analyses. The Kevex data for the site, therefore, simulate the screening data (leach values) rather than a total elemental analysis. 2. At a second Superfund site, the values for chromium, manganese, iron, strontium, barium and lead were total analyses and were based on the fundamental parameters equations. All the values are high, as was expected. The values for the field duplicate samples from this site ranged from exact duplication to a maximum of 46.54 percent relative standard deviation (RSD), whereas our laboratory duplicate samples showed a range from exact duplication to a maximum of 5-7 percent RSD (for barium). This difference in ranges indicates a problem in the field homogenization and splitting techniques, 3. At another Superfund site, we responded to a request from EPA Region X to provide XRP field analysis capability. Within the necessary time frame and at no cost to EPA1 Columbia Scientific Instruments provided an X-Met 840 XRF system (see Table 2) for this site demonstration. The objective was to screen different areas to locate two sources of soil for soil-amendment studies. One source was to have high concentrations of lead and zinc, and the other was to have low or "background" concentrations. We conducted 20 in situ analyses on four sites in leas than 90 minutes. For each position at each site, we placed the probe on the soil surface and performed the analysis. We wrote the position number and the concentrations for lead and zinc on a wooden stake that was driven into the soil at the site of analysis. On the following day, we began determining the locations of the stakes by using a Brunton compass, 300-foot tape, and known benchmarks. While the coordinate positions were being determined, each position was reanalyzed. For the reanalysis, we had recalibrated the X-Met 840 with standards provided by Lockheed-EMSCO. By recalibrating, we extended the linear dynamic range of the calibration curve; some of the reanalyses were as much as 5 times higher than the original analyses as a result of scatter and particle size ranges in the matrices of the new standards.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  169  We completed the mapping and reanalysis in 5 hours. In addition, we collected six samples to be used as standards for this site. Quality Assurance, Work, and Safety Plan for Field-Portable Systems We are developing a safety plan for use with undergoing field testing revised and incorporated  generalized quality assurance, work, and field-portable XRF systems. The plan is at a Superfund site. Subsequently, it will be into the generalized field method.  Project Report When all facets of the system development phase have been completed, we will prepare a project report on the results. DEVELOPMENT OP CLP XRP LABORATORY METHOD X-ray fluorescence is not currently an approved CLP method. To give credibility to XRP as an analytical technique, and as a parallel project to the development of field-portable systems, we will write a method that will be presented as an alternative CLP method at an upcoming CLP scientific review. Such a method, once approved, could provide laboratory workers with an economical, rapid alternative to current CLP methods. COMMERCIALIZING THE PEDERALLY PONDED PROTOTYPE As a parallel objective to system testing conducted by BMSL-LV, NASA will conduct a market survey to evaluate the opportunities for use of a field-portable XRP system. The information from this survey will provide data useful in conducting negotiations with companies interested in commercializing a prototype system. A federally funded prototype that has already been subjected to initial field testing (the MM1, see Table 2) will serve as the basic instrument from which a production instrument will be introduced commercially. Commercial production will be initiated through contract agreement between the selected manufacturer and EMSL-LV. A further project objective is to develop an advanced prototype field-portable XRF system (MM2). The technology for the proposed design changes exists off-the-shelf. With minor adaptation, these features can be incorporated into the MM2 prototype or into the  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  170  commercial version. should include:  Design considerations for the next prototype  •  Reconfiguration of the computer to include a 20 megabyte hard disk, 6.6 megabytes of RAM memory, an 1MB peak height analyzer card, a power supply that can drive the computer and the probe, and a remote keyboard and screen. The redesigned computer system also should be configured as a backpack.  •  Redesign of the probe system to incorporate the Peltier (thermal-electrically cooled) detector technology. The redesigned system should include a remote on-off switch as a function key on the computer keyboard.  •  Evaluation of new power sources and recharge capabilities.  •  Upgraded software.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  171  SECTION 3 FUTURE APPLICATIONS  The field-portable XRP technology has potential application in areas other than hazardous waste screening. Refinement and transfer of the technology, as well as manufacturer cooperation are likely to identify further uses of the technology. At present, we are exploring applications in the following areas: 1. Asbestos Identification—There is a need to identify and quantify fibrous and serpentine minerals. The prototype X-ray diffraction system built by the Naval Research Laboratories was designed to distinguish between fibrous and platy serpentine minerals only. Because new requirements and restrictions have been applied to asbestos in recent years, the prototype needs further development. By interfacing X-ray diffraction and XRF, data could be collected, analyzed, and quantified in the field. No such prototypes exist. 2. Metals Uptake in Living Plants (Region X)-Field-portable XRF systems can be used to measure the heavy metal ion uptake in flora near Superfund sites. This capability will be useful in establishing toxic levels and in measuring exposure to herbivores. 3. Zeolite Soil-Amendment Study (Region X)—Field-portable XRF systems can be used to measure concentrations of metals in soils; the length of time soils must remain fallow before planting is safe can then be determined. 4. Lead and Tin in Paint—Federal and state agencies could use field-portable XRF systems to diagnose and monitor lead and tin concentrations in the paint used in older buildings. 5. Ground-Water Monitoring—By redesigning the prototype probe to operate as a downhole probe, field portable systems could yield real-time concentration data for ground-water monitoring. The immediate feedback could reduce the costs incurred and could increase the amount of data produced during ground-water monitoring activities. 6. Water Treatment—On-line XRF system can give real-time concentration data. Field-portable systems could be used for this quality control application.  th  Proceedings of the 13 Annual British Columbia Mine Reclamation Symposium in Vernon, BC, 1989. The Technical and Research Committee on Reclamation  172  SECTION 4 REFERENCES Berven, B. A., M. S. Blair, and C. A- Little, 1987. Automation of the Radiological Survey Process: USRADS Ultrasonic Ranging and Data System. In: Proceedings of the 1987 International Decommissioning Symposium. Conf-871018-Vol.2. Richland, Washington. Raab, G. A-, D. Cardenas, and S. J. Simon, 1987- Evaluation of a Prototype Field-Portable X-Ray Fluorescence System for Hazardous Waste Screening. EPA/600/4-87/021. U.S. Environmental Protection Agency, Las Vegas, Nevada. U.S. EPA, 1987. Data Quality Objectives for Remedial Response Activities: Development Process. BPA/540/G-87/003, U.S. Environmental Protection Agency, Washington, D.C.  

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