A highly sensitive spectrophotometric method with solid-phase extraction for the determination of methylmercury in human hair

Methylmercury is the most toxic among the mercury species. In order to provide a quick method to screen samples for methylmercury, a highly sensitive spectrophotometric method was established. The method was based on formation of the red complex of methylmercury with thio-Michler's ketone, which can be extracted with n-butanol. The organic layer was determined at a maximum absorption wavelength of 564 nm. The Lambert-Beer law was obeyed for methylmercury from 1.00 × 10-7 mol/L to 2.00 × 10-5 mol/L with a correlation coefficient of 0.9992. The detection limit was 3 × 10-8 mol/L. The method was used to determine methylmercury in human hair. The recovery was from 94% to 102%, and the relative standard deviation was 2.5%. The results agreed with those obtained by gas chromatography with electron capture detection.