Dataset for: Unprecedented Ultrahigh resolution FT-ICR Mass Spectrometry and Parts-Per-Billion Mass Accuracy Enable Direct Characterization of Nickel and Vanadyl Porphyrins in Petroleum from Natural Seeps

We investigated a sample from a natural petroleum seep, an underwater asphalt volcano (Il Duomo (#4332-1)) discovered in 2007 off the coast of southern California in the Santa Barbara basin. Atmospheric pressure photoionization (APPI) Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) provides ultrahigh resolving power and subppm mass error(<50 ppb) to identify nickel porphyrin isotopes for unambiguous elemental composition assignment. This dataset reports the results of positive mode APPI FT-ICR MS preformed on the Il Duomo sample. In total 73959 peaks were found between 200 and 1196.28 m/z. Additionally, nickel and vanadyl petrorphyrin mass spectrum data from broadband APPI FT-ICR are included. These data resolve isobaric overlaps to confirm elemental fine structure of nickel and vanadyl porpyhrins.