Generation of multi-element reference materials on PTFE filters mimicking ambient aerosol characteristics

摘要

Multi-element reference materials (ME-RMs) mimicking atmospheric aerosol composition were generated using certified multi-element solutions on PTFE filters for use in calibration and quality checks of x-ray fluorescence (XRF) analysis. The ME-RMs reference loadings were assigned using an approach based on two assumptions: the accuracy of potassium (K) measured by energy-dispersive XRF (EDXRF) analysis at the University of California-Davis, and no change in the chemical profile of multi-element solutions when deposited on PTFE filters. A subset of ME-RMs was analyzed by EDXRF and inductively coupled plasma-mass spectrometry (ICP-MS) to check the agreement between the two methods and the reference loadings. Several statistical metrics revealed good agreements for Na, Al, Si, S, K, Ti, V, Mn, Fe, Co, Ni, Se, As, and Pb. Selected ME-RMs were tested for short-and long-term stability and homogeneity of deposit; they were shown to be homogeneously deposited and, except for Cl and Br, stable when handled and stored properly. The generated ME-RMs have the potential to fill a gap in the currently available XRF quality assurance resources by providing known element loadings in the range of interest for atmospheric aerosol measurements.