Development of a simple and rapid method for methylmercury analysis in seafood and its application on canned tuna fish samples in Riyadh Markets

Methylmercury is a potent toxin that is bioaccumulated and amplified all across the food chain, putting individuals who feed predatory fish or eat fish as an essential component in their diet in danger worldwide. Pollution with methylmercury creates a significant threat to public health as this toxin is mainly found in fish. To determine the toxicity of this compound, A unique method has been developed, with limited or replaced use of chemicals, especially more hazardous substances, reaching sensitive levels at low concentrations excellent efficiency reduces expenses and consumables by eliminating some non-essential solutions at the core of the analysis method.

The method has been developed from (EUR 25830 EN 2013), which expresses the bulk of the organic mercury content in seafood. Methylmercury was analyzed using a direct mercury analyzer and validation was performed according to the internal validation procedure developed according to Eurachem guidelines. The method was tested on random samples of canned tuna fish from the local market in Riyadh for the first time in SFDA labs. The quantification limit is 0.0055 mg/kg of methylmercury, less than the last method (EUR 25830 EN 2013), which was 0,010 mg/kg with excellent efficiency (Recovery is 86.7%). Methylmercury shows 33.1% of the total mercury in the sample. All results were below the Maximum Residue Limit MRL according to GSO CAC 193/ 2017.

Following up on monitoring and evaluating health risk assessments is recommended due to the common use of tuna and its permanent availability in the market.

Posted by: Mostafa Alsamti, Senior Lab Expert, Saudi food and Drug Authority, Saudi Arabia (16-Apr-2024)