Gas Chromatography-Inductively Coupled Plasma-Mass Spectrometry for Mercury Speciation in Seafood

A method for mercury speciation in seafood was designed by on-line coupling gas chromatography (GC) to inductively coupled plasma mass spectrometry (ICP-MS) with an improved interface. The detection limits (S/N = 3) of methylmercury (MeHg(I)) and ethylmercury (EtHg(I)) were 0.5 pg and 1.0 pg (as Hg), respectively. The quantitative limits (S/N = 8) were 1.5 pg and 2.8 pg for MeHg(I) and EtHg(I), respectively. The linear range of MeHg(I) and EtHg(I) determination was 1–1000 pg. The hybrid technique was applied for the speciation analysis of mercury in three certified reference materials, 14 fish, and shellfish samples collected from local markets. The measured MeHg(I) concentrations was 3.7–236.6 ng g−1 (as Hg), and no EtHg(I) was detected. The recovery of MeHg(I) in real samples was in the range of 91%–102%.