Determination of inorganic and methyl mercury in biological samples by high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry

High performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) has been developed for the determination of inorganic and methyl mercury in biological samples. Different techniques used to extract inorganic and methyl mercury from biological samples were also evaluated. The samples were sonicated to extract inorganic and methyl mercury in the system of 5 mol/L HCl. A 5% (V/V) methanol-water mobile phase containing 0.06 mol/L ammonium acetate, 20 μg/L Bi and 0.1% (V/V) 2-mercaptoethanol and a C ₁₈ reversed-phase column (5 μm, 3.9 mm x 150 mm) was used for separation of CH ₃Hg ⁺ and Hg ²⁺ by HPLC. The concentrations of CH ₃Hg ⁺ and Hg ²⁺ in eluent were detected by ICP-MS. Total four certified reference materials including human hair (GBW 07601), prawn (GBW 08572) , fish (IAEA MA-B-3/TM) and bovine liver (GBW 080193) were analyzed. The results showed good accordance with the certified values. The detection limits of the method for inorganic and methyl mercury were 0.3 μg/L and 0.2 μg/L, respectively.