Simple and sensitive method for the determination of methylmercury in hair using thin-layer chromatography with thermal decomposition gold amalgamation atomic absorption spectrophotometry

An improved method is described for the determination of methylmercury (MeHg) in human hair that is based on thin-layer chromatography and thermal decomposition gold amalgamation atomic absorption spectrophotometry. The dithizone extraction and application procedure of this technique were optimized, thus improving its sensitivity and robustness and enabling the use of less toxic solvents than other approaches. The limit of detection was 0.18 ng MeHg (as Hg), corresponding to 0.018 mg MeHg kg -1 of hair relative to a 10 mg sample. This method is appropriate for detecting MeHg in hair at the approximate reference dose level established by the United States Environmental Protection Agency.