Overview
Dufault and colleagues report a small pilot study in which an FDA investigator collected 20 high fructose corn syrup samples from three US manufacturers in February 2005, and university chemists measured total mercury by cold vapor AAS. Mercury was detected in 9 of 20 samples. The authors suggest mercury-cell chlor-alkali reagents (caustic soda, hydrochloric acid) used in corn wet-milling as the source, but could not confirm it.
Key numbers
- Manufacturer A (5 samples of 42% and 5 of 55% HFCS): 9 below the detection limit of 0.005 ug/g, one at 0.012 ug mercury (Hg)/g (Table 1).
- Manufacturer B (42% HFCS): 2 below DL, then 0.350, 0.390 and 0.065 ug Hg/g (Table 1).
- Manufacturer C (55% HFCS): 0.130, 0.400, 0.570, 0.110 and 0.240 ug Hg/g (Table 1).
Methods (brief)
About 1 g of syrup was microwave-digested in nitric acid, diluted in hydrochloric acid and analysed in triplicate by cold vapor AAS. NIST Oyster Tissue 1566b gave 0.036 ug/g against a certified 0.037 ug/g; spike recovery averaged 98.8%.
Evidence Fitness
Direct evidence for the high-fructose-corn-syrup page, with sound QA for total mercury, but only 20 samples from three manufacturers collected in a single week in 2005, so it says little about current supply. It is published as a Commentary and did not measure foods made with HFCS. Mercury was not speciated.