Thin-window electron probe X-ray microanalysis of individual atmospheric particles above the North Sea

A recently developed, automated, standardless, quantitative analytical method, based on electron probe X-ray microanalysis using thin-window energy-dispersive X-ray detector technology, has proven to be a valuable tool for single particle analysis with the determination of the concentrations of light and heavier elements. The combined knowledge of low-Z element concentrations and air mass backward trajectories could give us information on the speciation of environmentally important chemical compounds and their reactions in the atmosphere. Individual marine aerosol particles collected over the North Sea with a nine-stage Berner cascade impactor were analysed using this new method, which resulted in a more profound characterization of the analysed aerosol samples. According to air mass backward trajectory analysis, it is inferred that the aerosol compositions of two samples (S1–S2) should be mostly under the marine influence, whereas the other two samples (S4–S5) under the continental influence. This inference is undoubtedly confirmed by the results from the single particle analysis. For the more marine samples (S1–S2), “pure” and “aged” sea salt particles are major chemical species encountered on all stage samples. Various types of particles from continental sources, such as aluminosilicates, ammonium sulfate, organic, iron oxide particles are mostly observed on all impactor stages for the more continental samples (S4–S5). This kind of detailed information on chemical compositions of aerosol samples which is provided by this analytical technique can be very much valuable for the study of atmospheric reactions of marine aerosols, which is linked to many environmental issues like e.g. nutrient deposition and marine eutrophication.