Abstract:

Crude oil is typically enriched in vanadium and nickel. Our objective is to determine if metal enrichment, including V or Ni, in oil contaminated marine sediments and beach sands can be an effective proxy for mapping oil contamination. Crude oil from the Macondo well was digested and analyzed via ICP-MS. Our analyses show V, Ni, Cu and Co concentrations of 0.77 ppm, 1.94 ppm, 130ppb, and 60 ppb, respectively.

Suggested Citation:

Hastings, David. 2014. Trace and minor element content of Macondo crude oil. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7RX9914

Publications:

Hastings, D. W., Bartlett, T., Brooks, G. R., Larson, R. A., Quinn, K. A., Razionale, D., … Hollander, D. J. (2019). Changes in Redox Conditions of Surface Sediments Following the Deepwater Horizon and Ixtoc 1 Events. Deep Oil Spills, 269–284. doi:10.1007/978-3-030-11605-7_16

Purpose:

Our objective is to determine metal content of Macondo crude oil, especially V and Ni. Enrichment of these metals could be exploited as a proxy for mapping oil contamination.

Data Parameters and Units:

ppm = parts per million or µg / g

Methods:

A crude oil sample (0.2 – 0.25 g) from the Macondo 252 well was digested with 7 mL 16 N nitric acid and 3 mL 30% hydrogen peroxide in triplicate at 175°C for thirty minutes in a Milestone Ethos EZ microwave oven in closed Teflon digestion vessels with internal temperature sensor. The resulting digest was filtered and serially diluted with ultra pure DI water to 1:10, 1:100, 1:1000. We analyzed these samples with an Agilent 7500cx ICP-MS with an octopole reaction cell located at University of South Florida College of Marine Science. Helium mode was used for V, Cr, Mn, Fe, Co, Ni, Cu, Sr, and Cd to reduce isobaric interferences and in no-gas mode for Mo, Ba, Re, and U. Prior to analysis, samples were spiked with an internal standard containing Ge, In, and Bi in order to correct for instrumental drift during analysis. Elemental concentrations were determined using a 6-point external calibration line.

Instruments:

The samples were analyzed at the ICP-MS facility at University of South Florida College of Marine Science with the assistance of Dr. Kelly A. Quinn. We used an Agilent 7500cx ICP-MS with an octopole reaction cell in helium mode for V, Cr, Mn, Fe, Co, Ni, Cu, Sr, and Cd to reduce isobaric interferences and in no-gas mode for Mo, Ba, Re, and U. Prior to analysis, samples were spiked with an internal standard containing Ge, In, and Bi in order to correct for instrumental drift during analysis.

Error Analysis:

Five oil samples were analyzed; precision is based on replicate analyses.

Individual Files: