Reversed-phase high-performance liquid chromatographic separation of inorganic mercury and methylmercury driven by their different coordination chemistry towards thiols

Since mercuric mercury (Hg2+) and methylmercury (CH3Hg+) display different toxicological properties in mammals, methods for their quantification in dietary items must be available. Employing Hg-specific detection, we have developed a rapid, isocratic, and affordable RP-HPLC separation of these mercurials using thiol-containing mobile phases. Optimal separation was achieved with a 50 mM phosphate-buffer containing 10 mM L-cysteine at pH 7.5. The separation is driven by the on-column formation of complexes between each mercurial and L-cysteine, which are then separated according to their different hydrophobicities. The developed method is compatible with inductively coupled plasma atomic emission spectrometry and was applied to analyze spiked human urine. (c) 2006 Elsevier B.V. All rights reserved.