Rapid determination of methyl mercury in fish and shellfish: method development

Area of Science:

• Analytical Chemistry
• Environmental Science
• Food Safety

Background:

• Methyl mercury is a toxic compound found in fish and shellfish.
• Accurate and rapid methods are needed for its determination.

Purpose of the Study:

• To modify the AOAC official first action method for faster methyl mercury determination.
• To validate the modified method against existing AOAC methods.

Main Methods:

• Tissue homogenization and acetone washing.
• Extraction of methyl mercury chloride using toluene.
• Analysis by electron capture gas chromatography (GC).

Main Results:

• Quantitation limit of 0.25 µg Hg/g.
• No significant difference between modified and official methods.
• Average recovery of 100.5% with coefficients of variation of 1-7%.

Conclusions:

• The modified method provides rapid and accurate determination of methyl mercury in fish and shellfish.
• Essentially all mercury in the analyzed samples was in organic form.