Uncertainty estimation in analysis of particulate-bound mercury in different size fractions of PM10 in ambient air

Different size fractions with aerodynamic diameters of (9.0-10.0) mu m, (5.8-9.0) mu m, (4.7-5.8) mu m, (3.3-4.7) mu m, (2.1-3.3) mu m, (1.1-2.1) mu m, (0.7-1.1) mu m, and (0.4-0.7) mu m of PM(10) were collected on glass fiber filter using 8-stage Andersen cascade impactor. Samples were extracted using microwave acid digestion, and analysis was performed by Direct Mercury Analyzer, DMA-80. Uncertainty resulted due to sampling and analytical procedure was calculated by applying bottom-up approach. Significant sources of uncertainty are estimated, and an uncertainty budget is prepared for each fraction. Repeatability showed maximum contribution to uncertainty budget followed by calibration curve and volume of air. Estimated expanded relative uncertainties at the 95% confidence interval for particulate-bound mercury in different size fractions were between 15 and 26%.