|MEI, NI - Shanghai Institute For Food And Drug Control|
|LIU, JIXIN - Chinese Academy Of Agricultural Sciences|
|MAO, XUEFEI - Chinese Academy Of Agricultural Sciences|
Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/2/2017
Publication Date: 8/2/2017
Citation: Mei, N., Lai, B., Liu, J., Mao, X., Chen, G. 2017. Speciation of trace mercury impurities in fish oil supplements. Food Control. 8:221-225.
Interpretive Summary: Fish oil supplement is becoming increasingly popular worldwide due to health benefits of omega-3 polyunsaturated fatty acids. However, mercury impurity causes a considerable concern because of its toxicity and bioaccumulation along the food chain. In this work, a new method was developed based on discriminative quantification using two UV light sources. With this rapid, low-cost, and friendly method, inorganic and organic mercury impurities were found to be only about 1% of those in fish, and thus much safer than seafood.
Technical Abstract: Fish oil (FO) supplement is becoming increasingly popular worldwide because of beneficial long-chain omega-3 polyunsaturated fatty acids. However, mercury (Hg) impurity causes considerable concern because of its toxicity and bioaccumulation. In this work, Hg impurities were extracted from FO by liquid-liquid partitioning. The sample solution was then mixed with a reductant (0.4% anthranilic acid-20% formic acid) and sequentially exposed to 311 and 254 nm UV radiation. The resulting Hg0 vapor was detected by atomic fluorescence spectrometry. Speciation was fulfilled by solving a set of two linear equations. This method achieved 0.50 and 0.63 ng mL-1 limits of detection for Hg++ and MeHg+, respectively. Average Hg++ and MeHg+ contents in FO samples (n=38), 0.67 +/- 0.45 and 1.1 +/- 1.3 ng mL-1, respectively, were 2-3 orders of magnitude lower than those in fish.