A speciation method based on isotope dilution and GC-MS was developed for the determination of methylmercury in fish samples. A spike containing 201Hg-enriched methylmercury was used to determine the methylmercury in tuna samples with excellent results.
The document details the development of a precise and accurate analytical method for determining methylmercury in fish samples, specifically tuna. The technique utilizes gas chromatography-mass spectrometry (GC-MS) with electron impact ionization and isotope dilution using a spike containing 201Hg-enriched methylmercury.
The concentration of the spike solution is 5.49 ± 0.02 µg g⁻¹ as Hg.
The mixture must be shaken mechanically for 5 hours.
The measurement of isotope ratios was performed using a 10-ms dwell-time per mass.