Rapid determination of trace methylmercury in natural crude medicine of animal origin

A rapid and simple method to determine methylmercury in natural crude medicine of animal origin was developed using gas chromatography electron capture detection (GC-ECD). Methylmercury, one of the forms of organomercury in nature, is much more toxic than inorganic and elemental mercury due to its lipid soluble property. The method is based on acidic digestion in hydrochloric acid solution following the extraction with toluene. The following parameters for the determination of methylmercury with GC-ECD were established: limit of detection 2 μg kg^-1, limit of quantification 8 μg kg^-1, linearity 10-300 ng mL^-1, reproducibility as relative standard deviations 11.8%, 10.7% and 1.7% for 300, 150, and 20 ppb solutions, respectively, and recovery 87.1-112.4%. The results on animal-origin natural medicines using the method developed in this study were assured by comparison with those obtained by the method derived for measuring methylmercury in fish.