Development of a liquid chromatography-inductively coupled plasma mass spectrometry method for the simultaneous determination of methylmercury and inorganic mercury in human blood

摘要

We developed and validated a liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS) method for simultaneous determination of methylmercury (MeHg) and inorganic mercury (I-Hg) in human blood samples. Thallium was used as an internal standard for determination of MeHg and Hg-196 was used as an internal standard for I-Hg determination. The blood samples were extracted using a 7% (v/v) HCl solution containing 1.5% (w/v) L-cysteine. A 10% (w/v) trichloroacetic acid solution was used to precipitate proteins in the extract. Mercury species were measured by LC-ICP-MS. The linear range of the assay was 0.08-60 ng/mL for MeHg and 0.05-2.5 ng/mL for I-Hg. The method was validated with the Certified Reference Materials Blood Mercury (Institut National de Sante Publique Quebec, Quebec, Canada) and Seronorm (TM) Trace Elements Whole Blood (Sero AS, Billingstad, Norway). Additional validation was performed by comparing the results obtained with those from a widely used gas chromatography method with electron-capture detection. The proposed method was applied to the simultaneous determination of MeHg and I-Hg in human blood samples. The LC-ICP-MS method provides precise, accurate, and robust determination of MeHg and I-Hg levels in human blood over a long period and has a simple and quick sample preparation. We expect that this method will contribute to large-scale evaluation of human exposure to mercury compounds in future.