| Abstract |
The characterization of the atomic absorption method of determining metals in particulates found in the air of workplaces is described. A dynamic aerosol generation and sampling system capable of simulating workplace atmospheres was designed, built, and characterized. The particle size of the generated aerosol was in the range of 0.1 to 10 micrometers. The position-to-position variation among the thirty sampling ports was less than plus or minus 2.5%, and the run-to-run repeatability was less than plus or minus 10%. Ruggedization of the analytical procedure using statistical screening techniques resulted in a modified procedure which was 'rugged' for the analysis of Be, Cd, Co, Cr, Cu, Mn, Mo, Ni, and Pb. Sixteen laboratories participated in the collaborative test. Three filter sample sets from the aerosol generation system containing Cd, Co, Cr, Ni, and Pb at three concentration levels and distributed over time were used. Time, metals, concentration, and laboratories were the variables studied. Analysis of variance of the collaborative data showed laboratories to be the significant factor for all metals and concentrations to be significant only for cadmium and lead. Although the analysis of variance showed statistically significant differences, the overall performance of the method was considered excellent. The overall recoveries and standard deviations for the metals on filters were: Cd, 100.8 plus or minus 9.9; Co, 97.6 plus or minus 13.9; Cr, 96.6 plus or minus 10.8; Ni, 98.6 plus or minus 10.3; and Pb, 98.7 plus or minus 12.2. |
