title: An Evaluation of Aerosol- and Liquid-Generated Silica Samples for Proficiency Analytical Testing.
abstract: SRI International has prepared dynamically generated silica samples since 1980 for the National Institute of Occupational Safety and Health (NIOSH) and the American Industrial Hygiene Association (AIHA) Proficiency Analytical Testing (PAT) programs. Aerosol-generated samples were developed in 1980 to more closely approximate real world samples and to improve intrabatch precision. Liquid-generated samples may provide tighter control limits, and this method has been reexamined as the generation procedure of choice. Sample preparation procedures have also been investigated to minimize analytical uncertainty and, hence, obtain a true evaluation of the sampling error. Samples were analyzed by SRI, NIOSH, and the Wisconsin Occupational Health Laboratory, using X-ray diffraction or Fourier transform infrared spectrometry (FTIR). Results were plotted and statistically evaluated, then compared to the existing PAT interlaboratory database.
authors.affiliation: Analytical Chemistry Manager, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025.
authors.forename: Terry
authors.initials: T
authors.lastname: Hayes
authors.affiliation: Analytical Chemistry Department, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025.
authors.forename: Helen
authors.initials: H
authors.lastname: Parish
authors.affiliation: National Institute of Occupational Safety and Health, Alice Hamilton Laboratory, 5555 Ridge Ave., Cincinnati, OH 45213.
authors.forename: Rosa
authors.initials: R
authors.lastname: Key-Schwartz
authors.affiliation: Wisconsin Occupational Health Laboratory, Wisconsin State Laboratory of Hygiene, PO Box 7996, Madison, WI 53707-7996.
authors.forename: Derek
authors.initials: D
authors.lastname: Popp
keywords: Fourier transform infrared spectrometry (FTIR); X-ray diffraction (XRD); aerosol-generation; liquid-generation; proficiency analytical testing; silica