“…via lube oil, and from redispersed particles from the inner surfaces of the manifold and exhaust 44,45 . Note that iron is resonantly ionized in our instrument, leading to substantial signal enhancements of the Fe + signal 37,47 , but also increased Ni + and V + peaks 31 . Due to their high sulfur content, heavy fuel oils show stronger sulfate signals compared to MGO and HVO.…”