Determination of As, Cd, Ni and Pb in PM10 – comparison of different sample work-up and analysis methods/Bestimmung von As, Cd, Ni und Pb in PM10 – Vergleich verschiedener Probenaufbereitungs- und Analysenverfahren

In 2015 the European Joint Research Center (JRC) for air quality in Ispra, Italy, carried out an intercomparison for the determination of PM10 and PM2.5 in ambient air. Five laboratories also analyzed the content of heavy metals (arsenic, cadmium, lead and nickel) in PM10 from filter samples collected during the intercomparison. Thus, all steps from sampling in the field to instrumental quantification of heavy metals in the laboratory could be statistically analyzed. The different techniques of sampling and sample work-up had no significant influence on the analysis results. However, the method of instrumental analysis strongly influenced them: The results of laboratories using the Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) coincided well in most cases. For laboratories using the Energy Dispersed X-Ray Fluorescence (ED-XRF) technique the uncertainty of the results strongly depended on the metal concentration. For cadmium the concentrations generally were too low for analysis by ED-XRF, for arsenic, lead and nickel the relative uncertainties decreased exponentially with increasing concentrations. The relation between metal concentration and the relative uncertainty of analysis results could be described as power functions. Analysis of lead and nickel by ED-XRF is well possible in the range of the EU limit and target values for these metals.