Determination of methylmercury in food commodities by gas-liquid chromatography with atomic emission detection.
A method was developed for determining methylmercury in various food commodities. The organomercurial species was converted to methylmercuric chloride by treatment of a sample homogenized with 1.8M HCl. The resulting chlorinated species was eluted from a Celite 545-sample homogenate column with methylene chloride. The eluate was treated with stannic chloride, and the analyte was isolated from coextractives by using a wide-bore capillary column with microwave-induced plasma atomic emission detection. The method was applied to both high- and low-moisture commodities during analysis of 32 samples of grains, cereal products, fruits, and vegetables. Methylmercury was found at trace levels (i.e., between a signal-to-noise ratio of 3:1 and 10:1) and up to 0.85 ppb. Recoveries of added methylmercury ranged from 70.0 to 114.0%. Limits of quantitation and detection were 0.63 and 0.24 pg on column, respectively, corresponding to 0.30 and 0.11 ng Hg/g sample for a 40 g sample treated according to the method.
U.S. Food and Drug Administration, Minneapolis, MN 55401, USA.
M R
MR
Madson
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RD
Thompson
D002849:Chromatography, Gas; D005504:Food Analysis; D007202:Indicators and Reagents; D008767:Methylmercury Compounds / Q000032:analysis*; D011786:Quality Control; D015203:Reproducibility of Results; D013054:Spectrophotometry, Atomic
D007202:Indicators and Reagents; D008767:Methylmercury Compounds