Fluorimetric determination of methylmercury as an ion-association complex with rhodamine B in the presence of iodide

Abstract

A fluorimetric method for the determination of methylmercury was established. The method was based on the formation of an ionic pair between iodide-methylmercury-rhodamine B in hydrochloric acid, which can be extracted with benzene. The fluorescence emission was measured at λex/λem 575/590 nm, and the experimental variables and possible interference were studied. The linear calibration range was 4 × 10-8 mol/L ∼ 5 × 10-7 mol/L with a correlation coefficient of 0.9992. The detection limit was 1 × 10-8 mol/L. The method was used to determine methylmercury in human hair. The recovery was in the range of 91% to 105% and the relative standard deviation was 2.8%. The results agreed with those obtained by gas chromatography with electron capture detection. © Springer-Verlag 2000.