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.

Analytical methods for the determination of trace beryllium in soils are needed so that anthropogenic sources of this element can be distinguished from native (background) levels of beryllium. In this work, a collaborative interlaboratory evaluation of a new extraction and fluorescence-based procedure for determining beryllium in soil samples was carried out to fulfil method validation requirements for ASTM International voluntary consensus standard test methods. A Canadian reference material, CCRMP Till-1 soil, with a background beryllium concentration of 2.4 microg g(-1), was selected for study. This certified reference material (CRM) was spiked and homogenized with varying levels of beryllium oxide in order to give batches of material with beryllium concentrations of 4.36 +/- 0.69, 11.5 +/- 0.7, 124 +/- 7 and 246 +/- 16 microg g(-1) (+/- values are standard deviations). In the interlaboratory study (ILS), which was carried out in accordance with an applicable ASTM International standard practice (ASTM E691), samples of these spiked soils were subjected to extraction in dilute ammonium bifluoride at approximately 90 degrees C for 40 h. Fluorescence measurement of the extracted beryllium was carried out via detection using the high quantum yield fluorophore, hydroxybenzoquinoline sulfonate (HBQS). Interlaboratory precision estimates from six participating laboratories ranged from 0.048 to 0.103 (relative standard deviations) for the five different beryllium concentrations. Pooled bias estimates resulting from this ILS were between -0.049 and 0.177 for the various beryllium levels. These figures of merit support promulgation of the analytical procedure as an ASTM International standard test method.

No abstract

A fluorescence method for determination of beryllium and beryllium oxide particles has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health. The procedure involves dissolution of samples in ammonium bifluoride solution and adding a small aliquot of extract to a basic hydroxybenzoquinoline sulfonate fluorescent dye and measuring itsfluorescence. This method is specific to beryllium and is not affected by the presence of other metals. However, the results from such a method may be compromised by organic fluorescent impurities which have optical characteristics similar to the beryllium-bonded hydroxybenzoquinoline sulfonate. This study demonstrates that such impurities can be effectively removed by activated charcoal without compromising the sensitivity of the method or any other test attributes.

Exposures to beryllium (Be), even at extremely low levels, can cause severe health effects in a percentage of those exposed; consequently, occupational exposure limits (OELs) promulgated for this element are the lowest established for any element. This work describes the advantages of using highly alkaline dye solutions for determination of Be in occupational hygiene and environmental samples by means of an optical molecular fluorescence technique after sample extraction in 1–3% (w˖w−1) aqueous ammonium bifluoride (NH4HF2). Improved attributes include the ability to further enhance the detection limits of Be in extraction solutions of high acidity with minimal dilution, which is particularly beneficial when NH4HF2 solutions of higher concentration are used for extraction of Be from soil samples. Significant improvements in Be method detection limits (MDLs) are obtained at levels many-fold below those reported previously for this methodology. Notably, MDLs for Be of <0.01 ng l−1 / 0.1 ng per sample have been attained, which are superior to MDLs routinely reported for this element by means of the most widely used ultra-trace elemental measurement technique, inductively coupled plasma mass spectrometry (ICP-MS). Very low MDLs for Be are essential in consideration of reductions in OELs for this element in workplace air by health organizations and regulatory agencies in the USA and internationally. Applications of enhanced Be measurements to air filter samples, surface wipe samples, soils and newly-designed occupational air sampler inserts are illustrated.