Since the U. S. Department of Energy (DOE) published the DOE Beryllium Rule (10 CFR 850) in 1999, DOE sites have been required to measure beryllium in air filter and surface wipe samples for purposes of worker protection and for release of materials from beryllium-controlled areas. Measurements in the nanogram range on a filter or wipe are typically required. Industrial hygiene laboratories have applied methods from various analytical compendia, and a number of issues have emerged concerning sampling and analysis practices. As a result, a committee of analytical chemists, industrial hygienists, and laboratory managers was formed in November 2003 to address the issues. The committee developed a baseline questionnaire and distributed it to DOE sites and other agencies in the U.S., Canada, and the U.K. The results of the questionnaire are presented in this paper. These results confirmed that a wide variety of practices was in use in the areas of sampling, sample preparation, and analysis. Additionally, although these laboratories are generally accredited by the American Industrial Hygiene Association (AIHA), there are inconsistencies in execution among accredited laboratories. As a result, there are significant opportunities for development of standard methods that could improve consistency. The current availabilities and needs for standard methods are further discussed in a companion paper.

No abstract

Beryllium metal and beryllium oxide are important industrial materials used in a variety of applications in the electronics, nuclear energy, and aerospace industries. These materials are highly toxic, they must be disposed of with care, and exposed workers need to be protected. Recently, a new analytical method was developed that uses dilute ammonium bifluoride for extraction of beryllium and a high quantum yield optical fluorescence reagent to determine trace amounts of beryllium in airborne and surface samples. The sample preparation and analysis procedure was published by both ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The main advantages of this method are its sensitivity, simplicity, use of lower toxicity materials, and low capital costs. Use of the technique for analyzing soils has been initiated to help meet a need at several of the U.S. Department of Energy legacy sites. So far this work has mainly concentrated on developing a dissolution protocol for effectively extracting beryllium from a variety of soils and sediments so that these can be analyzed by optical fluorescence. Certified reference materials (CRM) of crushed rock and soils were analyzed for beryllium content using fluorescence, and results agree quantitatively with reference values.

Researchers at Los Alamos National Laboratory (LANL) developed a field-portable fluorescence method for the measurement of trace beryllium in workplace samples such as surface dust and air filters. The technology has been privately licensed and is commercially available. In cooperation with the Analytical Subcommittee of the Beryllium Health and Safety Committee, we have carried out a collaborative interlaboratory evaluation of the LANL field-portable fluorescence method. The interlaboratory study was conducted for the purpose of providing performance data that can be used to support standard methods. Mixed cellulose ester (MCE) membrane filters and Whatman 541 filters were spiked with beryllium standard solutions so that the filters spanned the range ≈0.05 − ≈0.5 µg Be per sample. Sets of these filters were then coded (to ensure blind analysis) and sent to participating laboratories, where they were analyzed. Analysis consisted of the following steps: 1. Removal of the filters from transport cassettes and placement of them into 15-mL centrifuge tubes; 2. mechanically-assisted extraction of the filters in 5 mL of 1% ammonium bifluoride solution (aqueous) for 30 min; 3.–4. filtration and transfer of sample extract aliquots (100 µL) into fluorescence cuvettes; 5. introduction of 1.9 mL of detection solution (to effect reaction of the fluorescence reagent with beryllium in the extracted sample); and 6. measurement of fluorescence at ≈475 nm using a portable fluorometer. This work presents performance data in support of a procedure that is targeted for publication as a National Institute for Occupational Safety and Health (NIOSH) method and as an ASTM International standard.

A collaborative interlaboratory evaluation of a newly standardized inductively coupled plasma mass spectrometry (ICP-MS) method for determining trace beryllium in workplace air samples was carried out toward fulfillment of method validation requirements for ASTM International voluntary consensus standard test methods. The interlaboratory study (ILS) was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Uncertainty was also estimated in accordance with ASTM D7440, which applies the International Organization for Standardization Guide to the Expression of Uncertainty in Measurement to air quality measurements. Performance evaluation materials (PEMs) used consisted of 37 mm diameter mixed cellulose ester filters that were spiked with beryllium at levels of 0.025 (low loading), 0.5 (medium loading), and 10 (high loading) microg Be/filter; these spiked filters were prepared by a contract laboratory. Participating laboratories were recruited from a pool of over 50 invitees; ultimately, 20 laboratories from Europe, North America, and Asia submitted ILS results. Triplicates of each PEM (blanks plus the three different loading levels) were conveyed to each volunteer laboratory, along with a copy of the draft standard test method that each participant was asked to follow; spiking levels were unknown to the participants. The laboratories were requested to prepare the PEMs by one of three sample preparation procedures (hotplate or microwave digestion or hotblock extraction) that were described in the draft standard. Participants were then asked to analyze aliquots of the prepared samples by ICP-MS and to report their data in units of mu g Be/filter sample. Interlaboratory precision estimates from participating laboratories, computed in accordance with ASTM E691, were 0.165, 0.108, and 0.151 (relative standard deviation) for the PEMs spiked at 0.025, 0.5, and 10 microg Be/filter, respectively. Overall recoveries were 93.2%, 102%, and 80.6% for the low, medium, and high beryllium loadings, respectively. Expanded uncertainty estimates for interlaboratory analysis of low, medium, and high beryllium loadings, calculated in accordance with ASTM D7440, were 18.8%, 19.8%, and 24.4%, respectively. These figures of merit support promulgation of the analytical procedure as an ASTM International standard test method, ASTM D7439.