Development of Environmental Analysis for Determination of Total Mercury in Fish Oil Pearls by Microwave Closed Vessels Digestion Coupled with ICP-OES

Abstract

Fish products have been shown to contain varying amounts of heavy metals, particularly mercury and fat-soluble pollutants from water pollution. This article describes a development and validation process for the determination of mercury in fish oil capsules as a contaminant by inductively coupled plasma optical emission spectrometry (ICP-OES) after closed-vessel microwave digestion in order to reach to a sufficient method due to high risk level of Hg, a highly toxic organic metal, existence in fish oil supplements. The validation was conducted using evaluation of several performance criteria. Linear range was regression coefficient (R2) is 0.999. Limits of detection were 0.0016 µg/l, recovery were assessed by spiking fish oil samples with different Hg concentrations, giving recovery from94-108% repeatability and intermediate precision relative standard deviations were 1.86 and 3.24. Validation results indicate that this method based on environmental analysis could be used in the laboratory for the routine determination with acceptable analytical performance. Furthermore, the method was supervised to determine mercury in 10 samples collected from the natural habitat of fish. The results of environmental analysis of mercury concentration in these samples comply with maximum daily mercury intake which is 1.6 μg/kg per week based on the World Health Organisation (WHO) and 0.1 μg/kg body weight per day according to the United States Environmental Protection Agency (EPA) and National Research Council (NRC).