Preparation, certification and interlaboratory analysis of workplace air filters spiked with high-fired beryllium oxide

Abstract

Occupational sampling and analysis for multiple elements is generally approached using various approved methods from authoritative government sources such as the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), as well as consensus standards bodies such as ASTM International. The constituents of a sample can exist as unidentified compounds requiring sample preparation to be chosen appropriately, as in the case of beryllium in the form of beryllium oxide (BeO). An interlaboratory study was performed to collect analytical data from volunteer laboratories to examine the effectiveness of methods currently in use for preparation and analysis of samples containing calcined BeO powder. NIST SRM(®) 1877 high-fired BeO powder (1100 to 1200 °C calcining temperature; count median primary particle diameter 0.12 μm) was used to spike air filter media as a representative form of beryllium particulate matter present in workplace sampling that is known to be resistant to dissolution. The BeO powder standard reference material was gravimetrically prepared in a suspension and deposited onto 37 mm mixed cellulose ester air filters at five different levels between 0.5 μg and 25 μg of Be (as BeO). Sample sets consisting of five BeO-spiked filters (in duplicate) and two blank filters, for a total of twelve unique air filter samples per set, were submitted as blind samples to each of 27 participating laboratories. Participants were instructed to follow their current process for sample preparation and utilize their normal analytical methods for processing samples containing substances of this nature. Laboratories using more than one sample preparation and analysis method were provided with more than one sample set. Results from 34 data sets ultimately received from the 27 volunteer laboratories were subjected to applicable statistical analyses. The observed performance data show that sample preparations using nitric acid alone, or combinations of nitric and hydrochloric acids, are not effective for complete extraction of Be from the SRM 1877 refractory BeO particulate matter spiked on air filters; but that effective recovery can be achieved by using sample preparation procedures utilizing either sulfuric or hydrofluoric acid, or by using methodologies involving ammonium bifluoride with heating. Laboratories responsible for quantitative determination of Be in workplace samples that may contain high-fired BeO should use quality assurance schemes that include BeO-spiked sampling media, rather than solely media spiked with soluble Be compounds, and should ensure that methods capable of quantitative digestion of Be from the actual material present are used.

Differences in metal concentration by particle size in house dust and soil

“…17, 18 However, nitric acid is not as efficient as stronger acids (i.e., hydrofluoric acid) at yielding a higher proportion of the metals encapsulated in crystalline minerals. 42 These minerals, like feldspar and quartz contribute more to the larger particle size fractions. Some of the previous studies obtained total metal concentration via instrumental neutron activation analysis from outdoor dust samples and also observed that smaller size fractions have higher concentrations of metals.…”

Optical molecular fluorescence determination of ultra-trace beryllium in occupational and environmental samples using highly alkaline conditions

“…Typically, MCE filters are used for air sampling and Whatman filters have been used for surface sampling. Certified MCE filters 21 spiked with known quantities of aqueous beryllium standards (diluted from 1000 μg ml −1 standard solution) and National Institute of Standards and Technology Standard Reference Material (NIST SRM ® ) 1877 beryllium oxide (NIST, Gaithersburg, MD, USA) were provided by High-Purity Standards (North Charleston, SC, USA). Certified reference material (CRM) soils with established beryllium contents were obtained from NIST and from the Canadian Certified Reference Materials Project (CCRMP, Ottawa, ON, Canada).…”

Evaluation of historical beryllium abundance in soils, airborne particulates and facilities at Lawrence Livermore National Laboratory

“…Our measurement of Be in SRM 2587 was high by about 50 %; this result may be due to uncertainty in the "information" Be concentration. A recent beryllium oxide powder standard (NIST SRM 1877) may be used in future analyses to determine recovery of beryllium oxide, particularly in matrix-matched samples (Winchester et al, 2009 andOatts et al, 2012). The high-fired beryllium oxide standard is more representative of the process-induced contamination that is likely to be found in beryllium handling and machining facilities.…”