The First International Intercomparison of Aerosol Trace Element Solubility Measurement

Atmospheric trace element solubility data produced using a variety of methods are not directly comparable. This study presents the first international intercomparison of 8 commonly used aerosol leaching protocols. Statistically lower soluble trace element fractions were obtained for all 7 trace elements analysed when using ultrapure water over ammonium acetate. Major differences in ultrapure water leach data were attributed to specific protocol features rather than the use of a batch or a flow-through technique. The ammonium leach resulted in significantly lower soluble fractions for crustal elements (aluminum, copper, iron and manganese) when compared to the Berger leach. While aeolian sources or transport history also influence the resulting trace element solubility measured, the development of "best practices" guidance on analytical protocols, data treatment and data validation would help reduce the variability in aerosol trace element solubility data produced worldwide.

Reference: Tang, M.J., Perron, M.M.G., Baker, A.R., et al. (2025). Measurement of soluble aerosol trace elements: inter-laboratory comparison of eight leaching protocols. Atmos. Meas. Tech., 18, 6125-6141. https://doi.org/10.5194/amt-18-6125-2025