From Wikipedia (entry – High Fructose Corn Syrup):
“In 2009, according to a peer-reviewed report published by Environmental Health [3] [4], high-fructose corn syrup has been found to be commonly tainted with mercury. Traces of mercury have been found in name-brand foods from makers such as Quaker, Hunt’s, Manwich, Hershey’s, Smucker’s, Kraft, Nutri-Grain, and Yoplait. Mercury is a highly toxic substance. It makes its way into high-fructose corn syrup during its production. Several chemicals are required to make high-fructose corn syrup, including caustic soda, hydrochloric acid, alpha-amylase, gluco-amylase, isomerase, powdered carbon, calcium chloride, and magnesium sulfate. Caustic soda and hydrochloric acid can contain traces of mercury.The Institute for Agriculture and Trade Policy, tested 55 consumer items, finding mercury in one third of the samples ranging from 30 to 350 parts per trillion. [43] In the United States the FDA has an action level for methylmercury in commercial marine and freshwater fish that is 1.0 parts per million (ppm), and in Canada the limit for the total of mercury content is 0.5 ppm. A 50-pound child eating just one 6-ounce serving of tuna with a mercury concentration of 0.385 ppm each week would exceed EPA’s reference dose by more than four times; a 140-pound woman eating the same amount would exceed EPA’s reference dose by 40%.[5]”