Atomic absorption and optical emission analysis of NASN atmospheric particulate samples for lead

Abstract

Lead analyses were performed on 945 quarterly composited particulate samples collected in 1970 by the National Air Surveillance Network by atomic absorption and spark excited optical emission spectroscopy. Duplicate analyses by atomic absorption (283.3-nm line) of 203 samples gave a pooled precision of 3.4 percent, RSD, with a detection limit of 0.50 ..mu..g/ml (0.10 ..mu..g/m/sup 3/). Duplicate optical emission (220.4-nm line) analyses of 800 samples gave a pooled precision of 11 percent, RSD, with a 9.6-..mu..g/ml (0.15 ..mu..g/m/sup 3/) detection limit. Spike recovery data were 93 +- 9 percent for atomic absorption and 102 +- 8 percent for optical emission data. Analysis of different portions of the same filters gave no significant difference by either method. The lead blank value for glass fiber filters was approximately 1 ..mu..g/in./sup 2/. For 795 samples run by both methods, the most frequently occurring difference in concentration was 8 percent which was statistically significant at the 99 percent confidence level. The emission data were higher than the atomic absorption data. No evidence was found for interferences on the 283.3-nm atomic absorption line. Times required for sample preparation and analysis were 1.2 to 1.4 man-hours per sample.