Non-traditional stable isotopic analysis for source tracing of atmospheric particulate matter

Atmospheric particulate matter (PM) pollution is one of the most serious global environmental problems, regarded to be associated with a wide range of diseases, e.g., cardiovascular disease, lung cancer. Mitigation of PM impact is hampered by highly uncertain source apportionment, which requires a valuable tracer to identify and constrain the emissions with high precision. Recently, with the rapid development of multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), non-traditional stable isotopes, e.g. silicon (Si), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), mercury (Hg), strontium (Sr), neodymium (Nd), have been used as valuable tracers for source apportionment of PM. Here, we summarized the latest advances in the analytical method and applications of non-traditional stable isotopes in source tracing of PM. Considering the limitation of the complex matrix effect of PM samples, a particular focus lies on a discussion of isotope analysis of PM, e.g., sample pretreatment, mass bias correction, and sensitivity improvement. Furthermore, the challenges and limitations of source tracing based on non-traditional stable isotopes were discussed and future perspectives were pointed out.