Volume 2, Issue 10 (November 2005)
Determination of Beryllium Compounds by NIOSH 7303
The fourth edition of the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods contains a new, simplified procedure for elemental analysis in workplace atmospheres by Inductively Coupled Argon Plasma Atomic Emission Spectroscopy (ICP-AES) titled NIOSH 7303. This method uses hot block digestion with hydrochloric acid (HCl) and nitric acid (HNO3). The method was presented as fully valid for elemental beryllium. It was further investigated and also found to be valid for beryllium sulfate tetrahydrate and has a recovery efficiency of about 80 % for beryllium oxide. Additionally, no matrix effect on beryllium analysis is apparent by NIOSH 7303 for five common sampling media: polyvinylchloride filters, mixed cellulose ester filters, Whatman® 42 filters, Ghost™ wipes, and Palintest® wipes. Finally, the method has been reevaluated and found to produce a beryllium detection level of 0.0002 μg/mL (0.005 μg/sample for air samples) and a quantifiable level of 0.0005 (0.0125 μg/sample). At this detection limit, the Occupational Safety and Health Administration Permissible Exposure Limit (PEL) of 0.002 mg/m3 can be achieved at the method's detection level with an air sample of 2.5 L or one tenth of the PEL with a sample of 25 L under the prescribed preparation and analytical conditions.