Determination of Methylmercury in Moss by Ethylation-Gas Chromatography-Cold Vapor Atomic Fluorescence Spectrometry with Solvent Extraction

An alkaline digestion and a solvent extraction technique were developed for the extraction of methylmercury in moss by aqueous-phase ethylation reaction with sodiumtetraethylborate,precollection onto a Tenax at room temperature,gas chromatographic separation and cold vapor atomic fluorescence spectrometric detection.The detection limit of this method was below0.003ng/g,and matrix spike recoveries of83%～120%were obtained with relative standard deviations≤8.6%for all samples analyzed.This method can alˉso be used to analyze trace methylmercury contents in other biological samples.