It has been clearly demonstrated that the effects of climate change are progressing faster and more intensely in the Arctic than elsewhere. In this area, the pollutants transported from mid-latitude countries via the atmosphere and climate-related parameters highly affect each other in an inter-related way. Therefore, assessing the transport pathways of the contaminants reaching the Arctic and their temporal variation is of the utmost importance. In this context, the use of Pb isotopic analysis performed via single-quadrupole ICP-MS (ICP-Q-MS) has been successfully applied in various studies.

In this work, an ICP-Q-MS based method was optimized to achieve the sensitivity required for the precise measurement of Pb isotope ratios at the low analytical concentrations found in environmental samples collected in the Arctic. Specifically, the inter-related effect of several parameters (for example, quadrupole voltages) on the signal intensity was investigated using the experimental design approach, and the operating conditions that maximized the sensitivity and, according to Poisson statistic, the internal precision were identified.

The final method was applied to analyze PM₁₀ samples collected from October 2018 to March 2023 at Ny-Ålesund (Svalbard Island, Norwegian Arctic). During the investigated period, the isotopic composition of the atmospheric Pb showcased an evident temporal variation, caused by a shift in the Pb sources with the changing of the seasons. Overall, these results were in good agreement with prior studies concerning this area. Moreover, unlike in previous years, the difference in Pb isotopic composition between spring and summer samples in 2022 was not significant, suggesting a persistent influence of the same source of Pb in the two seasons.