Published on January 23, 2008
Which Components of Crude Oil Dissolve in Water?: Which Components of Crude Oil Dissolve in Water? Lateefah Stanforda, Sunghwan Kimb, Geoffrey C. Kleina, Donald F. Smitha, Ryan P. Rodgersa,c,*, and Alan G. Marshalla,c,* Stanford, L.A.; Kim, S.; Klein, G.C.; Smith, D.F.; Rodgers, R.P. and Marshall, A.G., Identification of Water-Soluble Heavy Crude Oil Organics. Acidic and Basic NSO Compounds in Fresh Water and Sea Water by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Environ. Sci. Technol. 2007, 41, 2696-2702. a Dept. of Chemistry and Biochemistry, Florida State Univ., Tallahassee, FL 32306, USA b Korean Basic Science Institute, 52 Yeoeun-Dong, Yusung-Gu, Daejeon 305-333, Korea c ICR Program, National High Magnetic Field Lab, Tallahassee, Florida 32310-4005, USA The first step in understanding petroleum crude oil spills is to identify which chemical components dissolve in water. Here, we use ultrahigh-resolution magnet-based mass spectrometry to resolve and identify, for the first time, thousands of different chemical components of crude oil and water exposed to that oil. Of the 7,000+ acidic species identified in South American crude oil, surprisingly many are water-soluble, and many more in pure water than in seawater (see Figure. Top: crude oil. Bottom: water-soluble components). Water solubility depends on molecular weight, size, and heteroatom (nitrogen, oxygen, sulfur) content. Acidic oxygen-containing chemicals are most prevalent in the water-solubles, whereas acidic nitrogen-containing chemicals are least soluble. In contrast, basic nitrogen-containing chemicals are water-soluble. (Peaks noted with an asterisk in the distilled water-soluble bases portion of the Figure are nitrogen/oxygen/sulfur- containing compounds too dilute to be detected in the parent oil.) Possible structures are shown for two of the chemical components. *Supported by NSF (DMR-00-84173), NHMFL, and Florida State University.