DETERMINATION OF ORGANIC (METHYL) MERCURY IN FISH BY GRAPHITE FURNACE ATOMIC-ABSORPTION SPECTROPHOTOMETRY

A method to determine organic (methyl) mercury in fish using graphite furnace atomic absorption spectrophotometry is described. Following initial acetone extraction, methylmercury is released from samples by acid cupric bromide, extracted into toluene. Addition of dithizone to the extract allows the determination of mercury in the furnace. The average recovery of added methyimercuric chloride at 2.00-and 4.00-μg levels is 97.7±5.5%. Detection limit is 0.08 μg Hg/g sample. Determination of methylmercury in aqueous sodium thiosulfate after partitioning from toluene, permits an autosampler to be used. Results of the analyses of several fish samples by this technique are compared to those of gas-liquid chromatography and Magos' selective atomic absorption method. © 1979, American Chemical Society. All rights reserved.