Determination of metals as markers of oilContamination in seafood by ICP-MS
Concern about fin fish, shell fish and bivalve contamination as a result of the 2010 BP Deepwater Horizon Gulf oil spill and others has become an increasingly important question. Polynuclear aromatic hydrocarbon (PAH) content has been used as an indicator of oil exposure and may help to define food safety. However, PAHs are rapidly metabolized and may not be detectable when the measurement is made, even though exposure has occurred. Metal determination, particularly nickel and vanadium, has been used to characterize oil for identification and to assess its ability for emulsification. These elements have also been shown to bioaccumulate in molluscs and may be used as a “watch” to monitor contamination. This work will demonstrate improved ICP-MS methodology to efficiently measure nickel, vanadium, and other elements in a variety of sea creatures at low concentrations. Sample preparation, detection limits, and interferences will be discussed.
Marine oil spills have become less common, but a serious cause of marine pollution contributing to seafood contamination (1, 2). Oil from natural seepages and non-point source runoff can also contribute to marine pollution. The Gulf oil spill of 2010 prompted questions on how best to monitor seafood for oil contamination. The National Oceanographic and Atmospheric Administration (NOAA) developed methodology for monitoring polynuclear aromatic hydrocarbons (PAH) compounds in seafood because they are present in oil and are carcinogenic (3). However, they are rapidly metabolized by fish and may not be detectable in fish that had been exposed to oil after a short time. In contrast, metals, which can also be toxic, may not be metabolized or may bioaccumulate and continue to be measured at levels above the native concentration. Nickel and vanadium are measured in oil to reduce chance of catalyst deactivation and have been used as a monitor for oil contamination in molluscs after a large spill off the coast of France (4, 5). The Erika oil contained nickel (45 mg kg−1) and vanadium (83 mg kg−1). Vanadium concentrations in crude oil have been rep ...